U.S. patent application number 12/127548 was filed with the patent office on 2008-09-25 for aromatic amine derivatives and electroluminescence device using the same.
This patent application is currently assigned to Idemitsu Kosan Co., Ltd.. Invention is credited to Masakazu FUNAHASHI, Masahiro KAWAMURA.
Application Number | 20080233434 12/127548 |
Document ID | / |
Family ID | 37717049 |
Filed Date | 2008-09-25 |
United States Patent
Application |
20080233434 |
Kind Code |
A1 |
KAWAMURA; Masahiro ; et
al. |
September 25, 2008 |
AROMATIC AMINE DERIVATIVES AND ELECTROLUMINESCENCE DEVICE USING THE
SAME
Abstract
An aromatic amine derivative with a specific structure and an
organic electroluminescence device which comprises at least one
organic thin film layer comprising a light emitting layer
sandwiched between a pair of electrode consisting of an anode and a
cathode, wherein at least one of the organic thin film layer
comprises the aromatic amine derivative singly or as its mixture
component. The organic electroluminescence device which exhibits an
enhanced current efficiency of light emission and emits blue light
with a prolonged lifetime is realized.
Inventors: |
KAWAMURA; Masahiro; (Chiba,
JP) ; FUNAHASHI; Masakazu; (Chiba, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Idemitsu Kosan Co., Ltd.
Chiyoda-ku
JP
|
Family ID: |
37717049 |
Appl. No.: |
12/127548 |
Filed: |
May 27, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11428969 |
Jul 6, 2006 |
7405326 |
|
|
12127548 |
|
|
|
|
Current U.S.
Class: |
428/704 |
Current CPC
Class: |
C07D 401/10 20130101;
C07D 409/10 20130101; C07D 409/12 20130101; C07C 211/61 20130101;
C09K 2211/1007 20130101; H01L 51/5048 20130101; C07D 401/12
20130101; C07C 2603/18 20170501; C09K 11/06 20130101; C07C 2603/26
20170501; C09K 2211/1014 20130101; H05B 33/14 20130101; C09K
2211/1011 20130101 |
Class at
Publication: |
428/704 |
International
Class: |
H01J 1/63 20060101
H01J001/63 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 8, 2005 |
JP |
2005-230127 |
Claims
1. An organic electroluminescence device which comprises at least
one organic thin film layer comprising a light emitting layer
sandwiched between a pair of electrode consisting of an anode and a
cathode, wherein at least one of the organic thin film layer
comprises: (A) a material for an organic electroluminescence device
comprising an aromatic amine derivative represented by the
following general formula (2) or by the following general formula
(3): ##STR00084## wherein Ar.sub.5 to Ar.sub.15 each independently
represents a substituted or unsubstituted aryl group having 6 to 30
ring carbon atoms or a substituted or unsubstituted heteroaryl
group having 5 to 30 ring carbon atoms; L.sub.3 to L.sub.7 each
independently represents a substituted or unsubstituted arylene
group having 6 to 30 ring carbon atoms or a substituted or
unsubstituted heteroarylene group having 5 to 30 ring carbon atoms;
and further, at least one of L.sub.3 or L.sub.4 in the general
formula (2) or at least one of L.sub.5 to L.sub.7 in the general
formula (3) is a coupling group expressed by a following general
formula (4): ##STR00085## wherein L.sub.8 and L.sub.9 each
independently represents a single bond, a substituted or
unsubstituted arylene group having 6 to 30 ring carbon atoms, a
substituted or unsubstituted heteroarylene group having 5 to 30
ring carbon atoms; R.sub.a represents a substituent and when
R.sub.a exists two or more, they may bond each other to form a
ring; and n represents an integer of 0 to 8; (B) a material for an
organic electroluminescence device comprising an aromatic amine
derivative represented by the following general formula (5):
##STR00086## wherein Ar.sub.16 to Ar.sub.19 each independently
represents a substituted or unsubstituted aryl group having 6 to 30
ring carbon atoms or a substituted or unsubstituted heteroaryl
group having 5 to 30 ring carbon atoms; L.sub.10 represents a
single bond; L.sub.11 represents a single bond, a substituted or
unsubstituted arylene group having 6 to 30 ring carbon atoms or a
substituted or unsubstituted heteroarylene group having 5 to 30
ring carbon atoms; R.sub.a represents a substituent and when
R.sub.a exists two or more, they may bond each other to form a
ring; and n represents an integer of 0 to 8; or (C) a mixture of
material (A) and material (B).
2. The organic electroluminescence device according to claim 1,
wherein the organic thin film layer comprises at least one of a
hole transporting region or a hole injecting region, and wherein at
least one of the hole transporting region or the hole injecting
region comprises the material for the organic electroluminescence
device.
3. The organic electroluminescence device according to claim 1,
wherein the organic thin film layer comprises at least one of a
hole transporting layer or a hole injecting layer, and wherein at
least one of the hole transporting layer or the hole injecting
layer comprises said material for the organic electroluminescence
device.
4. The organic electroluminescence device according to claim 1,
wherein the organic thin film layer comprises a light emitting
layer and wherein the light emitting layer comprises said material
for the organic electroluminescence device.
5. The organic electroluminescence device according to claim 1,
wherein said light emitting layer comprises said material for the
organic electroluminescence device in an amount of 0.1 to 20% by
weight.
6. The organic electroluminescence device according to claim 1,
which emits bluish light.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent
application Ser. No. 11/428,969, filed on Jul. 6, 2006, which
claims priority to Japanese patent application JP 2005-230127,
filed on Aug. 8, 2005.
TECHNICAL FIELD
[0002] The present invention relates to an organic
electroluminescence ("electroluminescence" will be occasionally
referred to as "EL", hereinafter) device. More particularly, it
relates to an organic EL device employing an aromatic amine
derivative as a light emitting material resultantly realizing a
prolonged lifetime, an enhanced efficiently of light emission and a
reasonable production cost.
BACKGROUND ART
[0003] An organic electroluminescence ("electroluminescence" will
be occasionally referred to as "EL", hereinafter) device is a
spontaneous light emitting device which utilizes the principle that
a fluorescent substance emits light by energy of recombination of
holes injected from an anode and electrons injected from a cathode
when an electric field is applied. Since an organic EL device of
the laminate type driven under a low electric voltage was reported
by C. W. Tang et al. of Eastman Kodak Company (C. W. Tang and S. A.
Vanslyke, Applied Physics Letters, Volume 51, Pages 913, 1987),
many studies have been conducted on organic EL devices using
organic materials as the constituting materials. Tang et al. used a
laminate structure using tris(8-quinolinolato)aluminum for the
light emitting layer and a triphenyldiamine derivative for the hole
transporting layer. Advantages of the laminate structure are that
the efficiency of hole injection into the light emitting layer can
be increased, that the efficiency of forming excited particles
which are formed by blocking and recombining electrons injected
from the cathode can be increased, and that excited particles
formed among the light emitting layer can be enclosed. As the
structure of the organic EL device, a two-layered structure having
a hole transporting (injecting) layer and an electron transporting
and light emitting layer and a three-layered structure having a
hole transporting (injecting) layer, a light emitting layer and an
electron transporting (injecting) layer are well known. To increase
the efficiency of recombination of injected holes and electrons in
the devices of the laminate type, the structure of the device and
the process for forming the device have been studied.
[0004] Conventionally, aromatic diamine derivatives described in
Patent Literature 1 below and aromatic diamine derivatives with
condensed rings described in Patent Literature 2 below have been
known as hole transporting materials for the organic EL devices.
Improving those aromatic amine derivatives, Patent Literature 3
below discloses a following Compound (A), and Patent Literature 4
below discloses an aromatic diamine compound represented by a
following general formula (B).
##STR00001##
[0005] In the general formula (B), at least one of A or B is an
atomic group forming a substituted or unsubstituted saturated 5 to
8 member-ring which may comprise a spiro bond.
[0006] Further, Patent Literature 5 below discloses an organic EL
device employing an aromatic triamine compound represented by a
following general formula (C). Furthermore, Patent Literature 6
below discloses an aromatic tetramine compound represented by a
following general formula (D).
##STR00002##
[0007] In the general formula (C), B.sup.1 and B.sup.2 each
independently represents a substituted or unsubstituted biphenylene
group. A in the general formula (D) is selected among the following
structures.
##STR00003##
[0008] Still further, Patent Literature 7 below and Patent
Literature 8 below each discloses 9-phenanthreneamine derivatives
represented by a following general formula (E) and a following
general formula (F) respectively.
##STR00004##
[0009] Ar.sup.1 to Ar.sup.4 in the general formula (E) are
expressed by a following structure.
##STR00005##
[0010] Although the organic EL devices employing those materials
exhibit improvement, they do not achieve practical performance yet
and accordingly, further prolonged lifetime, further enhanced
efficiency of light emission and further acceralated mobility were
eagerly demanded. [0011] Patent Literature 1: U.S. Pat. No.
4,720,432 [0012] Patent Literature 2: U.S. Pat. No. 5,061,569
[0013] Patent Literature 3: Japanese Registered Patent No. 3508984
[0014] Patent Literature 4: Japanese Unexamined Patent Application
Laid-Open No. 2002-080433 [0015] Patent Literature 5: Japanese
Registered Patent No. 3565870 [0016] Patent Literature 6: Japanese
Registered Patent No. 3220950 [0017] Patent Literature 7: Japanese
Unexamined Patent Application Laid-Open No. Heisei 11 (1999)-135261
[0018] Patent Literature 8: Japanese Unexamined Patent Application
Laid-Open No. 2002-212151
DISCLOSURE OF THE INVENTION
[0019] The present invention has been made to overcome the above
problems and has an object of providing a material comprising an
aromatic amine derivative for an organic EL device satisfying a
reduction of its driving voltage and an enhancement of its
efficiency of light emission simultaneously, together with
maintaining its prolonged lifetime.
[0020] As a result of extensive researches for overcoming the above
problems, the inventors have found that by employing an aromatic
amine derivative represented by any one of following general
formulae (1) to (3) and (5), an organic EL device with low driving
voltage and with an enhanced efficiency of light emission together
with maintaining its prolonged lifetime can be fabricated. Such
being the case, the present invention has been accomplished on the
basis of the foregoing findings and information.
[0021] Thus, the present invention provides an aromatic amine
derivative represented by any one of following general formulae (1)
to (3):
##STR00006##
wherein Ar.sub.1 to Ar.sub.4 each independently represents a
substituted or unsubstituted aryl group having 6 to 30 ring carbon
atoms or a substituted or unsubstituted heteroaryl group having 5
to 30 ring carbon atoms; L.sub.1 and L.sub.2 each independently
represents a single bond, a substituted or unsubstituted arylene
group having 6 to 30 ring carbon atoms, a substituted or
unsubstituted heteroarylene group having 5 to 30 ring carbon atoms;
when both L.sub.1 and L.sub.2 are single bonds, however, a case
where both Ar.sub.1 and Ar.sub.3 each represents a substituted or
unsubstituted phenyl group and further, a case where both Ar.sub.2
and Ar.sub.4 each represents a substituted or unsubstituted
biphenylyl group or a substituted or unsubstituted phenyl group is
excluded; R.sub.a represents a substituent and when R.sub.a exists
two or more, they may bond each other to form a ring; and n
represents an integer of 0 to 8.
##STR00007##
[0022] In the general formulae (2) and (3), Ar.sub.5 to Ar.sub.15
each independently represents a substituted or unsubstituted aryl
group having 6 to 30 ring carbon atoms or a substituted or
unsubstituted heteroaryl group having 5 to 30 ring carbon atoms;
L.sub.3 to L.sub.7 each independently represents a substituted or
unsubstituted arylene group having 6 to 30 ring carbon atoms, a
substituted or unsubstituted heteroarylene group having 5 to 30
ring carbon atoms; and further, at least one of L.sub.3 or L.sub.4
in the general formula (2) or at least one of L.sub.5 to L.sub.7 in
the general formula (3) is a coupling group expressed by a
following general formula (4):
##STR00008##
wherein L.sub.8 and L.sub.9 each independently represents a single
bond, a substituted or unsubstituted arylene group having 6 to 30
ring carbon atoms or a substituted or unsubstituted heteroarylene
group having 5 to 30 ring carbon atoms; R.sub.a represents a
substituent and when R.sub.a exists two or more, they may bond each
other to form a ring; and n represents an integer of 0 to 8.
[0023] Further, the present invention provides a material for an
organic EL device comprising the aromatic amine derivative
represented by any one of the above general formulae (1) to (3),
together with a material for an organic EL device represented by a
following general formula (5):
##STR00009##
wherein Ar.sub.16 to Ar.sub.19 each independently represents a
substituted or unsubstituted aryl group having 6 to 30 ring carbon
atoms or a substituted or unsubstituted heteroaryl group having 5
to 30 ring carbon atoms; L.sub.10 and L.sub.11 each independently
represents a single bond, a substituted or unsubstituted arylene
group having 6 to 30 ring carbon atoms or a substituted or
unsubstituted heteroarylene group having 5 to 30 ring carbon atoms;
R.sub.a represents a substituent and when R.sub.a exists two or
more, they may bond each other to form a ring; and n represents an
integer of 0 to 8.
[0024] The material for the organic EL device of the present
invention is employable as a hole injecting material, a hole
transporting material or a dopant.
[0025] The present invention provides an organic EL device which
comprises at least one organic thin film layer comprising a light
emitting layer sandwiched between an anode and a cathode, wherein
at least one of the organic thin film layer comprises the material
for the organic EL device singly or as its mixture component.
[0026] In the organic EL device of the present invention, the
material for the organic EL device is employed for at least one of
a hole injecting region or a hole transporting region.
[0027] In the organic EL device of the present invention, the
material for the organic EL device is employed for at least one of
a hole injecting layer or a hole transporting layer.
[0028] In the organic EL device of the present invention, the
material for the organic EL device is employed for a light emitting
layer.
[0029] In the organic EL device of the present invention, the light
emitting layer contains the material for the organic EL device in
an amount of 0.1 to 20% by weight.
[0030] The organic EL device of the present invention emits bluish
light.
[0031] It is particularly preferable that the material for the
organic EL device of the present invention is employed for the hole
transporting region; and further preferably, a superior organic EL
device is obtainable when the material for the organic EL device of
the present invention is employed for the hole transporting
layer.
EFFECTS OF THE INVENTION
[0032] When the material for the organic EL device represented by
any one of the general formulae (1) to (3), and (5) is employed for
any one of the organic thin film layers, preferably for the hole
transporting region or the light emitting region, more preferably
for the hole transporting layer or the light emitting layer, and
further more preferably for the hole transporting layer, it enables
to fabricate the organic EL device which emits blue light at low
driving voltage, with an enhanced efficiency of light emission and
with prolonged lifetime.
THE PREFERRED EMBODIMENT TO CARRY OUT THE INVENTION
[0033] The present invention provides an aromatic amine derivative
represented by any one of following general formulae (1) to
(3):
##STR00010##
[0034] In the general formula (1), Ar.sub.1 to Ar.sub.4 each
independently represents a substituted or unsubstituted aryl group
having 6 to 30 ring carbon atoms or a substituted or unsubstituted
heteroaryl group having 5 to 30 ring carbon atoms; L.sub.1 and
L.sub.2 each independently represents a single bond, a substituted
or unsubstituted arylene group having 6 to 30 ring carbon atoms or
a substituted or unsubstituted heteroarylene group having 5 to 30
ring carbon atoms; when both L.sub.1 and L.sub.2 are single bonds,
however, a case where both Ar.sub.1 and Ar.sub.3 each represents a
substituted or unsubstituted phenyl group and further, where both
Ar.sub.2 and Ar.sub.4 each represents a substituted or
unsubstituted biphenylyl group or a substituted or unsubstituted
phenyl group is excluded; R.sub.a represents a substituent and when
R.sub.a exists two or more, they may bond each other to form a
ring; and n represents an integer of 0 to 8.
##STR00011##
[0035] In the general formulae (2) and (3), Ar.sub.5 to Ar.sub.15
each independently represents a substituted or unsubstituted aryl
group having 6 to 30 ring carbon atoms or a substituted or
unsubstituted heteroaryl group having 5 to 30 ring carbon atoms;
L.sub.3 to L.sub.7 each independently represents a substituted or
unsubstituted arylene group having 6 to 30 ring carbon atoms or a
substituted or unsubstituted heteroarylene group having 5 to 30
ring carbon atoms; and further, at least one of L.sub.3 or L.sub.4
in the general formula (2) or at least one of L.sub.5 to L.sub.7 in
the general formula (3) is a coupling group expressed by a
following general formula (4):
##STR00012##
wherein L.sub.8 and L.sub.9 each independently represents a single
bond, a substituted or unsubstituted arylene group having 6 to 30
ring carbon atoms, a substituted or unsubstituted heteroarylene
group having 5 to 30 ring carbon atoms; R.sub.a represents a
substituent and when R.sub.a exists two or more, they may bond each
other to form a ring; and n represents an integer of 0 to 8.
[0036] Examples of the substituted or unsubstituted aryl group
having 6 to 30 ring carbon atoms include phenyl group, 1-naphthyl
group, 2-naphthyl group, 1-anthracenyl group, 2-anthracenyl group,
9-anthracenyl group, 1-phenanthryl group, 2-phenanthryl group,
3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group,
1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group,
1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl
group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl
group, p-terphenyl-3-yl group, p-terphenyl-2-yl group,
m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl
group, o-tolyl group, m-tolyl group, p-tolyl group, p-t-butylphenyl
group, p-(2-phenylpropyl)phenyl group, 3-methyl-2-naphthyl group,
4-methyl-1-naphthyl group, 4-methyl-1-anthryl group,
4'-methylbiphenyl-yl group, 4''-t-butyl-p-terphenyl-4-yl group,
fluorenyl group, etc. Preferable examples are phenyl group,
naphthyl group, biphenylyl group, terphenylyl group and phenanthryl
group.
[0037] Examples of a substituted or unsubstituted fused aromatic
group having 10 to 20 ring carbon atoms include naphthyl group,
phenanthryl group, anthranyl group, pyrenyl group, crycenyl group,
acenaphthyl group, fluorenyl group, and so on; preferably naphthyl
group and phenanthryl group. Preferable examples include phenyl
group, naphthyl group, biphenyl group, anthranil group, phenanthryl
group, pyrenyl group, crycenyl group and fluorenyl group.
Particularly preferable examples are phenyl group and naphthyl
group.
[0038] Examples of the substituted or unsubstituted heteroarylene
group having 5 to 30 ring carbon atoms include pyridyl group,
pyrazyl group, quinolyl group, isoquinolyl group, phenanthroryl
group, furyl group, benzofuryl group, dibenzofuryl group, thienyl
group, dibenzothienyl group, benzothienyl group, pyrrolyl group,
indolyl group, carbazolyl group, imidazolyl group, benzimidazolyl
group, etc. Preferable examples are pyridyl group, quinolyl group,
carbazolyl group and indolyl group.
[0039] Examples of the substituted or unsubstituted arylene group
having 6 to 30 ring carbon atoms include phenylene group,
biphenylene group, terphenylene group, quarterphenylene group,
naphthylene group, anthracenylene group, phenanthrylene group,
chrycenylene group, a pyrenylene group, fluorenylene group,
2,-6-diphenylnaphthalene-4',4''-ene group,
2-phenylnaphthalene-2,4'-ene group, etc. Preferable examples are
phenylene group, biphenylene group, terphenylene group,
fluorenylene group and naphthylene group.
[0040] Examples of the substituted or unsubstituted heteroaryl
group having 5 to 30 ring carbon atoms include monovalent group of
pyridine, quinoline, thiophene, furan, carbazole, dibenzofuran,
dibenzothiophene, fluorenone, oxazole, oxadiazole, thiadiazole,
etc. Preferable examples are pyridine, carbazole and thiophene.
[0041] Examples of the substituted or unsubstituted heteroarylene
group having 5 to 30 ring carbon atoms include pyridyl group,
pyrazyl group, quinolyl group, isoquinolyl group, phenanthroryl
group, furyl group, benzofuryl group, dibenzofuryl group, thienyl
group, dibenzothienyl group, benzothienyl group, pyrrolyl group,
indolyl group, carbazolyl group, imidazolyl group, benzimidazolyl
group, etc. Preferable examples are pyridyl group, quinolyl group,
carbazolyl group and indolyl group.
[0042] Examples of the substituent for the aryl group, arylene
group, heteroaryl group and heteroarylene group include alkyl group
(alkyl group preferably having 1 to 20 carbon atoms, more
preferably having 1 to 12 carbon atoms and particularly preferably
having 1 to 8 carbon atoms; examples include methyl group, ethyl
group, iso-propyl group, tert-butyl group, n-octyl group, n-decyl
group, n-hexadecyl group, cyclopropyl group, cyclopentyl group,
cyclohexyl group, etc.); alkenyl group (alkenyl group preferably
having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon
atoms and particularly preferably having 2 to 8 carbon atoms;
examples include vinyl group, allyl group, 2-butenyl group,
3-pentenyl group, etc.); alkynyl group (alkynyl group preferably
having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon
atoms and particularly preferably having 2 to 8 carbon atoms;
examples include propargyl group, 3-pentynyl group, etc.); amino
group (amino group preferably having 0 to 20 carbon atoms, more
preferably having 0 to 12 carbon atoms and particularly preferably
having 0 to 6 carbon atoms; examples include amino group,
methylamino group, dimethylamino group, diethylamino group,
diphenylamino group, dibenzylamino group, etc.); alkoxy group
(alkoxy group preferably having 1 to 20 carbon atoms, more
preferably having 1 to 12 carbon atoms and particularly preferably
having 1 to 8 carbon atoms; examples include methoxy group, ethoxy
group, butoxy group, etc.); aryloxy group (aryloxy group preferably
having 6 to 20 carbon atoms, more preferably having 6 to 16 carbon
atoms and particularly preferably having 6 to 12 carbon atoms;
examples include phenyloxy group, 2-naphthyloxy group, etc.); acyl
group (acyl group preferably having 1 to 20 carbon atoms, more
preferably having 1 to 16 carbon atoms and particularly preferably
having 1 to 12 carbon atoms; examples include acetyl group, benzoyl
group, formyl group, pivaloyl group, etc.); alkoxycarbonyl group
(alkoxycarbonyl group preferably having 2 to 20 carbon atoms, more
preferably having 2 to 16 carbon atoms and particularly preferably
having 2 to 12 carbon atoms; examples include methoxycarbonyl
group, ethoxycarbonyl group, etc.); aryloxycarbonyl group
(aryloxycarbonyl group preferably having 7 to 20 carbon atoms, more
preferably having 7 to 16 carbon atoms and particularly preferably
having 7 to 10 carbon atoms; examples include phenyloxycarbonyl
group, etc.); acyloxy group (acyloxy group preferably having 2 to
20 carbon atoms, more preferably having 2 to 16 carbon atoms and
particularly preferably having 2 to 10 carbon atoms; examples
include acetoxy group, benzoyloxy group, etc.); acylamino group
(acylamino group preferably having 2 to 20 carbon atoms, more
preferably having 2 to 16 carbon atoms and particularly preferably
having 2 to 10 carbon atoms; examples include acetylamino group,
benzoylamino group, etc.); alkoxycarbonylamino group
(alkoxycarbonylamino group preferably having 2 to 20 carbon atoms,
more preferably having 2 to 16 carbon atoms and particularly
preferably having 2 to 12 carbon atoms; examples include
methoxycarbonylamino group, etc.); aryloxycarbonylamino group
(aryloxycarbonylamino group preferably having 7 to 20 carbon atoms,
more preferably having 7 to 16 carbon atoms and particularly
preferably having 7 to 12 carbon atoms; examples include
phenyloxycarbonylamino group, etc.); sulfonylamino group
(sulfonylamino group preferably having 1 to 20 carbon atoms, more
preferably having 1 to 16 carbon atoms and particularly preferably
having 1 to 12 carbon atoms; examples include methanesulfonylamino
group, benzensulfonylamino group, etc.); sulfamoyl group (sulfamoyl
group preferably having 0 to 20 carbon atoms, more preferably
having 0 to 16 carbon atoms and particularly preferably having 0 to
12 carbon atoms; examples include sulfamoyl group, methylsulfamoyl
group, dimethylsulfamoyl group, phenylsulfamoyl group, etc.);
carbamoyl group (carbamoyl group preferably having 1 to 20 carbon
atoms, more preferably having 1 to 16 carbon atoms and particularly
preferably having 1 to 12 carbon atoms; examples include carbamoyl
group, methylcarbamoyl group, diethylcarbamoyl group,
phenylcarbamoyl group, etc.); alkylthio group (alkylthio group
preferably having 1 to 20 carbon atoms, more preferably having 1 to
16 carbon atoms and particularly preferably having 1 to 12 carbon
atoms; examples include methylthio group, ethylthio group, etc.);
arylthio group (arylthio group preferably having 6 to 20 carbon
atoms, more preferably having 6 to 16 carbon atoms and particularly
preferably having 6 to 12 carbon atoms; examples include phenylthio
group, etc.); sulfonyl group (sulfonyl group preferably having 1 to
20 carbon atoms, more preferably having 1 to 16 carbon atoms and
particularly preferably having 1 to 12 carbon atoms; examples
include mesyl group, tosyl group, etc.); sulfinyl group (sulfinyl
group preferably having 1 to 20 carbon atoms, more preferably
having 1 to 16 carbon atoms and particularly preferably having 1 to
12 carbon atoms; examples include methanesulfinyl group,
benzenesulfinyl group, etc.); ureide group (ureide group preferably
having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon
atoms and particularly preferably having 1 to 12 carbon atoms;
examples include ureide group, methylureide group, phenylureide
group, etc.); phosphoricamide group (phosphoricamide group
preferably having 1 to 20 carbon atoms, more preferably having 1 to
16 carbon atoms and particularly preferably having 1 to 12 carbon
atoms; examples include diethylphosphoricamide group,
phenylphosphateamide group, etc.); hydroxy group; mercapto group;
halogen atom (for example, fluorine atom, chlorine atom, bromine
atom, iodine atom); cyano group; sulfo group; carboxyl group; nitro
group; hydroxamicacid group; sulfino group; hydrazino group; imino
group; heterocyclic group (heterocyclic group preferably having 1
to 30 carbon atoms, more preferably having 1 to 12 carbon atoms;
examples of the hetero atom include nitrogen atom, oxygen atom,
sulfur atom; specific examples of the heterocyclic group include
imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl,
morpholino, benzoxazolyl, benzimidazolyl, benzothiazolyl,
carbazolyl, etc.); silyl group (silyl group preferably having 3 to
40 carbon atoms, more preferably having 3 to 30 carbon atoms and
particularly preferably having 3 to 24 carbon atoms; examples
include trimethylsilyl group, triphenylsilyl group, etc.); etc.
Those substituent may be further substituted. Furthermore, when
there are two or more substituents, the substituents may be the
same with or different from each other. Moreover, in a case where
it is possible, they may couple each other to form a ring.
[0043] Examples of the substituent R.sub.a in the general formulae
(1) to (4) include alkyl group (alkyl group preferably having 1 to
20 carbon atoms, more preferably having 1 to 12 carbon atoms and
particularly preferably having 1 to 8 carbon atoms; examples
include methyl group, ethyl group, iso-propyl group, t-butyl group,
n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group,
cyclopentyl group, cyclohexyl group, etc.); alkenyl group (alkenyl
group preferably having 2 to 20 carbon atoms, more preferably
having 2 to 12 carbon atoms and particularly preferably having 2 to
8 carbon atoms; examples include vinyl group, allyl group,
2-butenyl group, 3-pentenyl group, etc.); alkynyl group (alkynyl
group preferably having 2 to 20 carbon atoms, more preferably
having 2 to 12 carbon atoms and particularly preferably having 2 to
8 carbon atoms; examples include propargyl group, 3-pentynyl group,
etc.); amino group (amino group preferably having 0 to 20 carbon
atoms, more preferably having 0 to 12 carbon atoms and particularly
preferably having 0 to 6 carbon atoms; examples include amino
group, methylamino group, dimethylamino group, diethylamino group,
diphenylamino group, dibenzylamino group, etc.); alkoxy group
(alkoxy group preferably having 1 to 20 carbon atoms, more
preferably having 1 to 12 carbon atoms and particularly preferably
having 1 to 8 carbon atoms; examples include methoxy group, ethoxy
group, butoxy group, etc.); aryloxy group (aryloxy group preferably
having 6 to 20 carbon atoms, more preferably having 6 to 16 carbon
atoms and particularly preferably having 6 to 12 carbon atoms;
examples include phenyloxy group, 2-naphthyloxy group, etc.); acyl
group (acyl group preferably having 1 to 20 carbon atoms, more
preferably having 1 to 16 carbon atoms and particularly preferably
having 1 to 12 carbon atoms; examples include acetyl group, benzoyl
group, formyl group, pivaloyl group, etc.); alkoxycarbonyl group
(alkoxycarbonyl group preferably having 2 to 20 carbon atoms, more
preferably having 2 to 16 carbon atoms and particularly preferably
having 2 to 12 carbon atoms; examples include methoxycarbonyl
group, ethoxycarbonyl group, etc.); aryloxycarbonyl group
(aryloxycarbonyl group preferably having 7 to 20 carbon atoms, more
preferably having 7 to 16 carbon atoms and particularly preferably
having 7 to 10 carbon atoms; examples include phenyloxycarbonyl
group, etc.); acyloxy group (acyloxy group preferably having 2 to
20 carbon atoms, more preferably having 2 to 16 carbon atoms and
particularly preferably having 2 to 10 carbon atoms; examples
include acetoxy group, benzoyloxy group, etc.); acylamino group
(acylamino group preferably having 2 to 20 carbon atoms, more
preferably having 2 to 16 carbon atoms and particularly preferably
having 2 to 10 carbon atoms; examples include acetylamino group,
benzoylamino group, etc.); alkoxycarbonylamino group
(alkoxycarbonylamino group preferably having 2 to 20 carbon atoms,
more preferably having 2 to 16 carbon atoms and particularly
preferably having 2 to 12 carbon atoms; examples include
methoxycarbonylamino group, etc.); aryloxycarbonylamino group
(aryloxycarbonylamino group preferably having 7 to 20 carbon atoms,
more preferably having 7 to 16 carbon atoms and particularly
preferably having 7 to 12 carbon atoms; examples include
phenyloxycarbonylamino group, etc.); sulfonylamino group
(sulfonylamino group preferably having 1 to 20 carbon atoms, more
preferably having 1 to 16 carbon atoms and particularly preferably
having 1 to 12 carbon atoms; examples include methanesulfonylamino
group, benzensulfonylamino group, etc.); sulfamoyl group (sulfamoyl
group preferably having 0 to 20 carbon atoms, more preferably
having 0 to 16 carbon atoms and particularly preferably having 0 to
12 carbon atoms; examples include sulfamoyl group, methylsulfamoyl
group, dimethylsulfamoyl group, phenylsulfamoyl group, etc.);
carbamoyl group (carbamoyl group preferably having 1 to 20 carbon
atoms, more preferably having 1 to 16 carbon atoms and particularly
preferably having 1 to 12 carbon atoms; examples include carbamoyl
group, methylcarbamoyl group, diethylcarbamoyl group,
phenylcarbamoyl group, etc.); alkylthio group (alkylthio group
preferably having 1 to 20 carbon atoms, more preferably having 1 to
16 carbon atoms and particularly preferably having 1 to 12 carbon
atoms; examples include methylthio group, ethylthio group, etc.);
arylthio group (arylthio group preferably having 6 to 20 carbon
atoms, more preferably having 6 to 16 carbon atoms and particularly
preferably having 6 to 12 carbon atoms; examples include phenylthio
group, etc.); sulfonyl group (sulfonyl group preferably having 1 to
20 carbon atoms, more preferably having 1 to 16 carbon atoms and
particularly preferably having 1 to 12 carbon atoms; examples
include mesyl group, tosyl group, etc.); sulfinyl group (sulfinyl
group preferably having 1 to 20 carbon atoms, more preferably
having 1 to 16 carbon atoms and particularly preferably having 1 to
12 carbon atoms; examples include methanesulfinyl group,
benzenesulfinyl group, etc.); ureide group (ureide group preferably
having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon
atoms and particularly preferably having 1 to 12 carbon atoms;
examples include ureide group, methylureide group, phenylureide
group, etc.); phosphoricamide group (phosphoricamide group
preferably having 1 to 20 carbon atoms, more preferably having 1 to
16 carbon atoms and particularly preferably having 1 to 12 carbon
atoms; examples include diethylphosphoricamide group,
phenylphosphateamide group, etc.); hydroxy group; mercapto group;
halogen atom (for example, fluorine atom, chlorine atom, bromine
atom, iodine atom); cyano group; sulfo group; carboxyl group; nitro
group; hydroxamicacid group; sulfino group; hydrazino group; imino
group; heterocyclic group (heterocyclic group preferably having 1
to 30 carbon atoms, more preferably having 1 to 12 carbon atoms;
examples of the hetero atom include nitrogen atom, oxygen atom,
sulfur atom; specific examples of the heterocyclic group include
imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl,
morpholino, benzoxazolyl, benzimidazolyl, benzothiazolyl,
carbazolyl, etc.); silyl group (silyl group preferably having 3 to
40 carbon atoms, more preferably having 3 to 30 carbon atoms and
particularly preferably having 3 to 24 carbon atoms; examples
include trimethylsilyl group, triphenylsilyl group, etc.); etc.
Those substituent may be further substituted. Furthermore, when
there are two or more substituents, the substituents may be the
same with or different from each other. Moreover, in a case where
it is possible, they may couple each other to form a ring.
[0044] Specific examples of aromatic amine derivative represented
by the general formulae (1) to (3) will be shown below, though not
particularly limited thereto.
##STR00013## ##STR00014## ##STR00015## ##STR00016## ##STR00017##
##STR00018## ##STR00019## ##STR00020## ##STR00021## ##STR00022##
##STR00023## ##STR00024## ##STR00025## ##STR00026## ##STR00027##
##STR00028## ##STR00029## ##STR00030## ##STR00031## ##STR00032##
##STR00033## ##STR00034## ##STR00035## ##STR00036## ##STR00037##
##STR00038## ##STR00039## ##STR00040## ##STR00041## ##STR00042##
##STR00043## ##STR00044## ##STR00045## ##STR00046## ##STR00047##
##STR00048##
[0045] The present invention provides a material for an organic EL
device comprising the aromatic amine derivative represented by any
one of the above general formulae (1) to (3), together with a
material for an organic EL device represented by a following
general formula (5):
##STR00049##
[0046] In the general formula (5), Ar.sub.16 to Ar.sub.19 each
independently represents a substituted or unsubstituted aryl group
having 6 to 30 ring carbon atoms or a substituted or unsubstituted
heteroaryl group having 5 to 30 ring carbon atoms; L.sub.10 and
L.sub.11 each independently represents a single bond, a substituted
or unsubstituted arylene group having 6 to 30 ring carbon atoms or
a substituted or unsubstituted heteroarylene group having 5 to 30
ring carbon atoms; R.sub.a represents a substituent and when
R.sub.a exists two or more, they may bond each other to form a
ring; and n represents an integer of 0 to 8. Specific examples of
Ar.sub.16 to Ar.sub.19, L.sub.10, L.sub.11 and R.sub.a are the same
as the aforementioned.
[0047] Further, the present invention provides an organic
electroluminescence device which comprises at least one organic
thin film layer comprising a light emitting layer sandwiched
between a pair of electrode consisting of an anode and a cathode,
wherein at least one of the organic thin film layer comprises the
material for the organic EL device represented by any one of the
general formulae (1) to (3) and (5) singly or as its mixture
component.
[0048] The material for the organic EL device in the present
invention provides a superior organic EL device when the material
is employed in a hole injecting region and/or a hole transporting
region or a light emitting region, preferably in a hole injecting
layer and/or a hole transporting layer or a light emitting layer,
further preferably in the hole transporting layer or the light
emitting layer.
[0049] It is preferable that the hole transporting layer or the
light emitting layer contains the material for the organic EL
device represented by any one of the general formulae (1) to (3)
and (5) in an amount of 0.1 to 20% by mass.
[0050] The organic EL device of the present invention emits bluish
light.
[0051] The construction of the organic EL device of the present
invention will be explained in detail below.
[0052] (1) Construction of the Organic EL Device
[0053] Typical examples of the construction of the organic EL
device of the present invention are shown below. However, the
present invention is not limited to those shown below.
(1) An anode/a light emitting layer/a cathode; (2) An anode/a hole
injecting layer/a light emitting layer/a cathode; (3) An anode/a
light emitting layer/an electron injecting layer/a cathode; (4) An
anode/a hole injecting layer/a light emitting layer/an electron
injecting layer/a cathode; (5) An anode/an organic semiconductor
layer/a light emitting layer/a cathode; (6) An anode/an organic
semiconductor layer/an electron barrier layer/a light emitting
layer/a cathode; (7) An anode/an organic semiconductor layer/a
light emitting layer/an adhesion improving layer/a cathode; (8) An
anode/a hole injecting layer/a hole transporting layer/a light
emitting layer/an electron injecting layer/a cathode; (9) An
anode/an insulating layer/a light emitting layer/an insulating
layer/a cathode; (10) An anode/an inorganic semiconductor layer/an
insulating layer/a light emitting layer/an insulating layer/a
cathode; (11) An anode/an organic semiconductor layer/an insulating
layer/a light emitting layer/an insulating layer/a cathode; (12) An
anode/an insulating layer/a hole injecting layer/a hole
transporting layer/a light emitting layer/an insulating layer/a
cathode; and (13) An anode/an insulating layer/a hole injecting
layer/a hole transporting layer/a light emitting layer/an electron
injecting layer/a cathode.
[0054] Among the above constructions, constructions (4) and (8) are
usually preferable.
[0055] Although the materials for the organic EL device of the
present invention may be employed for any of the above organic
layers, it is preferable that it is contained in a light emitting
region or a hole transporting region among those construction
elements. It is particularly preferable that they are contained in
the hole transporting layer.
[0056] (2) Substrate which Transmits Light
[0057] In general, the organic EL device is produced on a substrate
which transmits light. It is preferable that the substrate which
transmits light has a transmittance of light of 50% or greater in
the visible wavelength-range of 400 to 700 nanometers. It is also
preferable that a flat and smooth substrate is employed.
[0058] As the substrate which transmits light, for example, glass
sheet and synthetic resin sheet are advantageously employed.
Specific examples of the glass sheet include soda ash glass, glass
containing barium and strontium, lead glass, aluminosilicate glass,
borosilicate glass, barium borosilicate glass and quartz. Specific
examples of the synthetic resin sheet include sheet made of
polycarbonate resins, acrylic resins, polyethylene terephthalate
resins, polyether sulfide resins and polysulfone resins.
(3) Anode
[0059] The anode in the organic EL device of the present invention
covers a role of injecting holes into a hole transport layer or
into a light emitting layer, and it is effective that the anode has
a work function of 4.5 eV or greater. Specific examples of the
material for the anode include indium tin oxide (ITO) alloy, indium
zinc oxide (IZO) alloy, tin oxide (NESA), gold, silver, platinum,
copper, lanthanoid, etc. Further, an alloy or a laminate of two
kinds or more among those in combination may be employable.
[0060] The anode can be prepared by forming a thin film of the
electrode material described above in accordance with a process
such as the vapor deposition process and the sputtering
process.
[0061] When the light emitted from the light emitting layer is
obtained through the anode, it is preferable that the anode has a
transmittance of the emitted light greater than 10%. It is also
preferable that the sheet resistivity of the anode is several
hundred .OMEGA./.quadrature. or smaller. The thickness of the anode
is, in general, selected in the range of from 10 nanometers to 1
.mu.m and preferably in the range of from 10 to 200 nanometers.
(4) Light Emitting Layer
[0062] In the organic EL device of the present invention, the light
emitting layer has the following functions:
[0063] Namely,
(1) The injecting function: the function of injecting holes from
the anode or the hole injecting layer and injecting electrons from
the cathode or the electron injecting layer when an electric field
is applied; (2) The transporting function: the function of
transporting injected charges (electrons and holes) by the force of
the electric field; and (3) The light emitting function: the
function of providing the field for recombination of electrons and
holes and leading the recombination to the emission of light.
[0064] Although there may be a difference between the capability of
the holes being injected and the capability of the electrons being
injected, and although there may be a grade about the transporting
function expressed by mobilities of the holes and the electrons, it
is preferable to move charges of either ones.
[0065] As the process for forming the light emitting layer, a well
known process such as the vapor deposition process, the spin
coating process and the Laser Beam (LB) process can be employed. It
is particularly preferable that the light emitting layer is a
molecular deposit film.
[0066] The molecular deposit film is a thin film formed by
deposition of a material compound in the gas phase or a thin film
formed by solidification of a material compound in a solution or in
the liquid phase. In general, the molecular deposit film can be
distinguished from the thin film (the molecular accumulation film)
formed in accordance with the LB process based on the differences
in the aggregation structure and higher order structures and
functional differences caused by these structural differences.
[0067] In addition, as disclosed in Japanese Patent Application
Laid-Open No. Showa 57 (1982)-51781, the light emitting layer can
also be formed by dissolving a binder such as a resin and the
material compounds into a solvent to prepare a solution, followed
by forming a thin film from the prepared solution in accordance
with the spin coating process or the like.
[0068] In the present invention, any well known light emitting
material other than the present invention may be optionally
contained in the light emitting layer, or a light emitting layer
containing any other well known light emitting material may be
laminated with the light emitting layer containing the light
emitting material of the present invention each in an extent of not
obstructing to achieve the object of the present invention
respectively.
[0069] With regard to the well known light emitting material, a
material having a fused aromatic ring such as anthracene or pyrene
in its molecule is particularly preferable. Specific examples will
be described below.
[0070] A light emitting material or a dopant to be used together
with the aromatic amine derivatives includes, for example,
anthracene, naphthalene, phenanthrene, pyrene, tetracene, coronene,
chrysene, fluorescein, perylene, phthaloperylene,
naphthaloperylene, perinone, phthaloperinone, naphthaloperinone,
diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole,
aldazine, bisbenzooxazoline, bisstyryl, pyrazine, cyclopentadiene,
quinolin metal complex, aminoquinolin metal complex, benzoquinolin
metal complex, imine, diphenylethylene, vinylanthracene,
diaminecarbazol, pyran, thiopyran, polymethyne, merocyanine,
imidazol chelate oxinoid compound, quinacridone, rubrene and
fluorescent dye, but not limited thereto.
[0071] A preferable host material to be used together with the
aromatic amine derivatives of the present invention includes
compounds represented by following general formulae (i) to
(ix).
[0072] An asymmetric anthracene represented by a following general
formula (1):
##STR00050##
[0073] In the above general formula (1), Ar represents a
substituted or unsubstituted fused aromatic group having 10 to 50
ring carbon atoms;
Ar' represents a substituted or unsubstituted aromatic group having
6 to 50 ring carbon atoms; X represents a substituted or
unsubstituted aromatic group having 6 to 50 ring carbon atoms, a
substituted or unsubstituted aromatic heterocyclic group having 5
to 50 ring atoms, a substituted or unsubstituted alkyl group having
1 to 50 carbon atoms, a substituted or unsubstituted alkoxy group
having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl
group having 6 to 50 carbon atoms, a substituted or unsubstituted
aryloxy group having 5 to 50 ring atoms, a substituted or
unsubstituted arylthio group having 5 to 50 ring atoms, a
substituted or unsubstituted alkoxycarbonyl group having 1 to 50
carbon atoms, a carboxyl group, a halogen atom, a cyano group, a
nitro group and a hydroxyl group; a, b and c each independently
represents an integer of 0 to 4; n represents an integer of a to 3;
and when n is 2 or greater, within a parentheses: [ ] may be the
same with or different from each other.
[0074] An asymmetric mono-anthracene derivative represented by a
following general formula (ii):
##STR00051##
[0075] In the general formula (ii), Ar.sup.1 and Ar.sup.2 each
independently represents a substituted or unsubstituted aromatic
ring group having 6 to 50 ring carbon atoms; m and n each
represents an integer of 1 to 4; however, in a case where m=n=1 and
at the same time, where each bonding position of Ar.sup.1 and
Ar.sup.2 to a benzene ring is monosymmetric each other, Ar.sup.1 is
different from Ar.sup.2, and in a case where m or n represents an
integer of 2 to 4, m is different from n;
R.sup.1 to R.sup.10 each independently represents a hydrogen atom,
a substituted or unsubstituted aromatic ring group having 6 to 50
ring carbon atoms, a substituted or unsubstituted aromatic
heterocyclic group having 5 to 50 ring atoms, a substituted or
unsubstituted alkyl group having 1 to 50 carbon atoms, a
substituted or unsubstituted cycloalkyl group, a substituted or
unsubstituted alkoxy group having 1 to 50 carbon atoms, a
substituted or unsubstituted aralkyl group having 6 to 50 carbon
atoms, a substituted or unsubstituted aryloxy group having 5 to 50
ring atoms, a substituted or unsubstituted arylthio group having 5
to 50 ring atoms, a substituted or unsubstituted alkoxycarbonyl
group having 1 to 50 carbon atoms, a substituted or unsubstituted
silyl group, a carboxyl group, a halogen atom, a cyano group, a
nitro group and a hydroxyl group.
[0076] An asymmetric pyrene derivative represented by a following
general formula (iii):
##STR00052##
[0077] In the general formula (iii), Ar and Ar' each represents a
substituted or unsubstituted aromatic group having 6 to 50 ring
carbon atoms;
L and L' each represents a substituted or unsubstituted phenylene
group, a substituted or unsubstituted naphthalenylene group, a
substituted or unsubstituted fluorenylene group or a substituted or
unsubstituted dibenzosilolylene group; m represents an integer of 0
to 2, n represents an integer of 1 to 4, s represents an integer of
0 to 2 and t represents an integer of 0 to 4; and, L or Ar bonds to
any one of 1 to 5 position of pyrene, also L' or Ar' bonds to any
one of 6 to 10 position thereof, however, when n+t makes an even
number, Ar, Ar', L and L' satisfy a following requirement (1) or a
requirement (2): (1) Ar.noteq.Ar' and/or L.noteq.L' (wherein
.noteq. means that each group has a different structure) (2) when
Ar=Ar' and L=L' (2-1) m.noteq.s and/or n.noteq.t, or (2-2) when m=8
and n=t, (2-2-1) both L and L' or pyrene each bonds respectively to
different positions of Ar and Ar', or (2-2-2) both L and L' or
pyrene each bonds respectively to the same position of Ar and Ar',
excluding a case where a pyrene derivative having both L and L' or
both Ar and Ar' bond to 1 and 6 positions thereof, or 2 and 7
positions thereof.
[0078] An asymmetric anthracene derivative represented by a
following general formula (Iv):
##STR00053##
[0079] In the general formula (Iv), A.sup.1 and A.sup.2 each
independently represents a substituted or unsubstituted fused
aromatic ring group having 10 to 20 ring carbon atoms;
Ar.sup.1 and Ar.sup.2 each independently represent a hydrogen atom,
a substituted or unsubstituted aromatic ring group having 6 to 50
ring carbon atoms; R.sup.1 to R.sup.10 each independently
represents a hydrogen atom, a substituted or unsubstituted aromatic
ring group having 6 to 50 ring carbon atoms, a substituted or
unsubstituted aromatic heterocyclic group having 5 to 50 ring
atoms, a substituted or unsubstituted alkyl group having 1 to 50
carbon atoms, a substituted or unsubstituted cycloalkyl group, a
substituted or unsubstituted alkoxy group having 1 to 50 carbon
atoms, a substituted or unsubstituted aralkyl group having 6 to 50
carbon atoms, a substituted or unsubstituted aryloxy group having 5
to 50 ring atoms, a substituted or unsubstituted arylthio group
having 5 to 50 ring atoms, a substituted or unsubstituted
alkoxycarbonyl group having 1 to 50 carbon atoms, a substituted or
unsubstituted silyl group, a carboxyl group, a halogen atom, a
cyano group, a nitro group or a hydroxyl group; Ar.sup.1, Ar.sup.2,
R.sup.9 and R.sup.10 each may be more than one, and two neighboring
groups thereof may form a saturated or unsaturated ring structure,
however, a case where the groups at 9 and 10 positions of
anthracene at the core are symmetrical about X-Y axis of symmetry
and bond each other is excluded.
[0080] An anthracene derivative represented by a following general
formula (v):
##STR00054##
[0081] In the general formula (v), R.sup.1 to R.sup.10 each
independently represents a hydrogen atom, an alkyl group, a
cycloalkyl group, an aryl group which may be substituted, an
alkoxyl group, an aryloxy group, an alkylamino group, an alkenyl
group, an arylamino group or a heterocyclic group which may be
substituted; a and b each represents an integer of 1 to 5, and when
both of a and b are 2 or greater, both R.sup.1 or both R.sup.2 may
be the same with or different from each other, additionally a
couple of R.sup.1 or both R.sup.2 may bond each other to form a
ring; a couple of R.sup.3 and R.sup.4, a couple of R.sup.5 and
R.sup.6, a couple of R.sup.7 and R.sup.8, and/or a couple of
R.sup.9 and R.sup.10 may bond each other to form a ring; L.sup.1
represents a single bond, --O--, --S--, --N(R)--, an alkylene group
or an arylene; wherein R represents an alkyl group, or an aryl
group which may be substituted.
[0082] An anthracene derivative represented by a following general
formula (vi):
##STR00055##
[0083] In the general formula (vi), R.sup.11 to R.sup.20 each
independently represents a hydrogen atom, an alkyl group, a
cycloalkyl group, an aryl group, an alkoxyl group, an aryloxy
group, an alkylamino group, an arylamino group or a heterocyclic
group which may be substituted; c, d, e and f each represents an
integer of 1 to 5, and when c, d, e and/or f are 2 or greater,
plural R.sup.11, plural R.sup.12, plural R.sup.16 or plural
R.sup.17 may be the same with or different from each other,
additionally plural R.sup.11, plural R.sup.12, plural R.sup.16 or
plural R.sup.17 may bond each other to form a ring; a couple of
R.sup.13 and R.sup.14, and/or a couple of R.sup.18 and R.sup.19 may
bond each other to form a ring; L.sup.2 represents a single bond,
--O--, --S--, --N(R)--, an alkylene group or an arylene; wherein R
represents an alkyl group, or an aryl group which may be
substituted.
[0084] A spirofluorene derivative represented by a following
general formula (vii):
##STR00056##
[0085] In the general formula (vii), A.sup.5 to A.sup.8 each
independently represented a substituted or unsubstituted biphenyl
group or a substituted or unsubstituted naphthyl group.
[0086] A compound containing a fused ring represented by a
following general formula (viii):
##STR00057##
[0087] In the general formula (viii), A.sup.9 to A.sup.14 each
independently represents a substituted or unsubstituted biphenyl
group or a substituted or unsubstituted naphthyl group as
aforementioned about A.sup.5 to A.sup.8, and R.sup.21 to R.sup.23
each independently represents a hydrogen atom, an alkyl group
having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon
atoms, an alkoxyl group having 1 to 6 carbon atoms, an aryloxy
group having 5 to 18 carbon atoms, an aralkyloxy group having 7 to
18 carbon atoms, an arylamino group having 5 to 16 carbon atoms, a
nitro group, a cyano group, an ester group having 1 to 6 carbon
atoms or a halogen atom, and at least one of A.sup.9 to A.sup.14
represents a fused aromatic ring comprising 3 or more rings.
[0088] A fluorene compound represented by a following general
formula (1x):
##STR00058##
[0089] In the general formula (1x), R.sub.1 and R.sub.2 each
independently represents a hydrogen atom, a substituted or
unsubstituted alkyl group, a substituted or unsubstituted aralkyl
group, a substituted or unsubstituted aryl group, a substituted or
unsubstituted heterocyclic group, a substituted amino group, a
cyano group or a halogen atom; both R.sub.1 and both R.sub.2
bonding to a different fluorene group may be the same with or
different from each other, and both R.sub.1 and R.sub.2 bonding to
the same fluorene group may be the same with or different from each
other; R.sub.3 and R.sub.4 each independently represents a hydrogen
atom, a substituted or unsubstituted alkyl group, a substituted or
unsubstituted aralkyl group, a substituted or unsubstituted aryl
group, or a substituted or unsubstituted heterocyclic group, and
both R.sub.3 and both R.sub.4 bonding to a different fluorene group
may be the same with or different from each other, and also both
R.sub.3 and R.sub.4 bonding to the same fluorene group may be the
same with or different from each other; Ar.sub.1 and Ar.sub.2 each
independently represents a substituted or unsubstituted fused
polycyclic aromatic group consisting of benzene rings of 3 or more
or a substituted or unsubstituted fused polycyclic heterocyclic
group comprising of benzene rings and hetero rings of 3 or more in
total; Ar.sub.1 and Ar.sub.2 may be the same with or different from
each other; and n represents an integer of 1 to 10.
[0090] Among the above host materials, an anthracene derivative is
preferable and a monoanthracene derivative is more preferable,
further an asymmetric anthracene is particularly preferable.
[0091] In addition, a phosphorescent compound may be employed as a
light emitting material for a dopant. A compound containing a
carbazole ring for a host material is preferable as the
phosphorescent compound. Although the dopant is a compound which is
able to emit light from triplet exciton and is not limited as long
as emitting light from triplet exciton, it is preferable that the
dopant is a metal complex containing at least a metal selected from
a group consisting of Ir, Ru, Pd, Pt, Os and Re.
[0092] A suitable host for phosphorescence comprising a compound
containing a carbazole ring is a compound having a function of
making a phosphorescent compound to emit light as a result of
energy transfer from its excitation state to the phosphorescent
compound. With regard to the host compound, any compound being able
to transfer exciton energy to the phosphorescent compound may be
selected, without particularly restricted, for the purpose as
appropriate. Any heterocyclic compound excluding a carbazole ring
may be contained.
[0093] Specific examples of the host compound include a carbazole
derivative, a triazole derivative, an oxazole derivative, an
oxadiazole derivatives, an imidazole derivative, a polyarylalkane
detivative, a pyrazoline derivative, a pyrazlone derivative, a
phenylene diamine derivative, an arylamine derivative, a calcone
derivative substituted by amine, a styrylanthracene derivative, a
fluorenone derivative, a hydrazone derivative, a stilbene
derivative, a silazane derivative, an aromatic tertiary amine
compound, a styrylamine compound, an aromatic dimethylidene type
compound, a porphyrin type compound, an anthraquinodimethane
derivative, an anthrone derivative, a diphenylquinon derivative, a
thiopyrandioxide derivative, a carbodimide derivative, a
fluorenylidene methane derivative, a distyrylpyrazine derivative,
heterocyclic tetracarboxylic anhydride such as a
naphthaleneperylene, a phthalocyanine derivative, a metal complex
or a metallophthalocyanine of 8-quinolinol derivative; various
metal complex polysilane-based compound represented by a metal
complex having a ligand of benzoxazole or benzothiazole; an
electro-conductive oligomer such as a poly(N-vinylcarbazole)
derivative, an aniline-based copolymer, a thiophene oligomer, a
polythiophene and so on; polymer compound such as a polythiophene
derivative, a polyphenylene derivative, a polyphenylenevinylene
derivative, a polyfluorene derivative and the like. The host
compounds may be used singly or in combination of two or more.
[0094] More specific examples include the following:
##STR00059## ##STR00060## ##STR00061##
[0095] The phosphorescent dopant is a compound capable of emitting
light from the triplet exciton. Although it is not restricted as
long as it emits light from the triplet exciton, it is preferable
that a metal complex comprises at least a metal selected from the
group of Ir, Ru, Pd, Pt, Os and Re. A porphyrin metal complex or an
orthometalized metal complex is particularly preferable. As the
porphyrin metal complex, a porphyrin platinum complex is
preferable. The phosphorescent compound may be employed singly or
in combination of two or more.
[0096] Although there are various ligands to form an orthometalized
metal complex, preferred ligands includes 2-phenylpyridine
derivatives, 7,8-benzoquinoline derivatives, 2-(2-thienyl)pyridine
derivatives, 2-(1-naphthyl)pyridine derivatives, 2-phenylquinoline
derivatives and the like. The derivatives may have substituent as
option. In particular, the derivatives having a fluorinated
compound or a trifluoromethyl group are preferable for a bluish
dopant. In addition, a ligand other than the above ligand such as
acetylacetonate and picric acid may be contained as an auxiliary
ligand.
[0097] The amount of the phosphorescent dopant in the light
emitting layer may be selected for the objective as appropriate
without particularly restricted, and for example, it may be
selected in the range of from 0.1 to 70% by mass, preferably in the
range of from 1 to 30% by mass. The emission is faint and the
advantage is not demonstrated when the amount is less than 0.1% by
mass. The concentration quenching becomes noticeable so that the
device performance is deteriorated when the amount is more than 70%
by mass.
[0098] Further, the light emitting layer may contain a hole
transporting material, a electron transporting material or a
polymer binder as option.
[0099] Furthermore, the thickness of the light emitting layer is,
in general, selected in the range of from 5 to 50 nanometers,
preferably in the range of from 7 to 50 nanometers and more
preferably in the range of from 10 to 50 nanometers. It is resulted
in difficulties to form the light emitting layer and to control
chromaticity thereof when the thickness is less than 5 nanometers,
and it may be resulted in danger of increasing driving voltage when
it is more than 50 nanometers.
(5) Hole Injecting Layer, Hole Transporting Layer
[0100] The hole injecting layer and the hole transporting layer are
layers which help injection of holes into the light emitting layer
and transport the holes to the light emitting region. The layers
exhibit a great mobility of holes and, in general, have an
ionization energy as small as 5.5 eV or smaller. For the hole
injecting layer and the hole transporting layer, a material which
transports holes to the light emitting layer at a small strength of
the electric field is preferable. A material which exhibits, for
example, a mobility of holes of at least 10.sup.-4 cm.sup.2/Vsecond
under application of an electric field of from 10.sup.4 to 10.sup.6
V/cm is preferable.
[0101] When the compound of the present invention is employed in
the hole transporting region, the hole injecting layer or the hole
transporting layer may be composed of only the compound of the
present invention singly or may be composed of both the compound of
the present invention and any other material in combination.
[0102] With regard to the material which may be employed for
forming the hole injecting layer or the hole transporting layer in
combination with the compound of the present invention, any
material having the foregoing preferable properties is employed
without particularly restricted, any arbitrary material select from
conventional material commonly used as a charge transporting
material for the holes in photoconductive materials and well known
material employed for the hole injecting layer in the EL device is
usable. Regarding with the aromatic amine derivative, a compound
expressed with a following general formula is employable.
##STR00062##
[0103] In the formula, Ar.sup.3 to Ar.sup.8, Ar.sup.11 to Ar.sup.13
and Ar.sup.21 to Ar.sup.23 each independently represents a
substituted or unsubstituted aromatic group having 6 to 50 ring
carbon atoms or a substituted or unsubstituted heteroaromatic group
having 5 to 50 ring atoms; a, b, c, p, q and r each independently
represents an integer of 0 to 3; and a couple of Ar.sup.3 and
Ar.sup.4, a couple of Ar.sup.5 and Ar.sup.6, and a couple of
Ar.sup.7 and Ar.sup.8 may bond each other to form a saturated or
unsaturated ring structure.
##STR00063##
[0104] In the formula, Ar.sup.1 to Ar.sup.4 each independently
represents a substituted or unsubstituted aromatic group having 6
to 50 ring carbon atoms or a substituted or unsubstituted
heteroaromatic group having 5 to 50 ring atoms; L is a coupling
group, and represents a single bond or a substituted or
unsubstituted aromatic group having 6 to 50 ring carbon atoms or a
substituted or unsubstituted heteroaromatic group having 5 to 50
ring atoms; X represents an integer of 0 to 5; and a couple of
Ar.sup.2 and Ar.sup.3 may bond each other to form a saturated or
unsaturated ring structure.
[0105] Specific examples include triazole derivatives (refer to
U.S. Pat. No. 3,112,197, etc.), oxadiazole derivatives (refer to
U.S. Pat. No. 3,189,447, etc.), imidazole derivatives (refer to
Japanese Examined Patent KOKOKU No. Shou 37-16096, etc.), poly
arylalkane derivatives (refer to U.S. Pat. Nos. 3,615,402,
3,820,989 and 3,542,544, Japanese Examined Patent KOKOKU Nos. Shou
45-555 and Shou 51-10983, Japanese Unexamined Patent Application
Laid Open Nos. Shou 51-93224, Shou 55-17105, Shou 56-4148, Shou
55-108667, Shou 55-156953, Shou 56-36656, etc.), pyrazoline
derivatives and pyrazolone derivatives (refer to U.S. Pat. Nos.
3,180,729 and 4,278,746, Japanese Unexamined Application Patent
Laid Open Nos. Shou 55-88064, Shou 55-88065, Shou 49-105537, Shou
55-51086, Shou 56-80051, Shou 56-88141, Shou 57-45545, Shou
54-112637, Shou 55-74546, etc.), phenylenediamine derivatives
(refer to U.S. Pat. No. 3,615,404, Japanese Examined Patent KOKOKU
Nos. Shou 51-10105, Shou 46-3712 and Shou 47-25336, Japanese
Unexamined Patent Application Laid Open Nos. Shou 54-53435, Shou
54-110536, Shou 54-119925, etc.), arylamine derivatives (refer to
U.S. Pat. Nos. 3,567,450, 3,180,703, 3,240,597, 3,658,520,
4,232,103, 4,175,961 and 4,012,376, Japanese Examined Patent KOKOKU
Nos. Shou 49-35702 and Shou 39-27577, Japanese Unexamined Patent
Application Laid Open Nos. Shou 55-144250, Shou 56-119132 and Shou
56-22437, West German Patent No. 1,110,518, etc.), Chalcone
derivatives which is substituted with amino group (refer to U.S.
Pat. No. 3,526,501, etc.), oxazole derivatives (disclosed in U.S.
Pat. No. 3,257,203, etc.), styryl anthracene derivatives (refer to
Japanese Unexamine Patent Application Laid Open No. Shou 56-46234,
etc.), fluorenone derivatives (refer to Japanese Unexamined Patent
Application Laid Open No. Shou 54-110837, etc.), hydrazone
derivatives (refer to U.S. Pat. Nos. 3,717,462, Japanese Unexamined
Patent Application Laid Open Nos. Shou 54-59143, Shou 55-52063,
Shou 55-52064, Shou 55-46760, Shou 55-85495, Shou 57-11350, Shou
57-148749, Hei 2-311591, etc.), stilbene derivatives (refer to
Japanese Unexamined Patent Application Laid Open Nos. Shou
61-210363, Shou 61-228451, Shou 61-14642, Shou 61-72255, Shou
62-47646, Shou 62-36674, Shou 62-10652, Shou 62-30255, Shou
60-93455, Shou 60-94462, Shou 60-174749, Shou 60-175052, etc.),
silazane derivatives (U.S. Pat. No. 4,950,950), polysilane-based
copolymers (Japanese Unexamined Patent Application Laid-Open No.
Hei 2-204996), aniline-based copolymers (Japanese Unexamined Patent
Application Laid-Open No. Hei 2-282263), an electroconductive
polymer oligomer which is disclosed in Japanese Unexamined Patent
Application Laid-Open No Hei 1-211399 (particularly, thiophene
oligomer), etc.
[0106] With regard to the material of the hole injecting layer, the
above materials are also employable, however, porphyrin compounds,
aromatic tertiary amine compounds and styryl amine compounds (refer
to U.S. Pat. No. 4,127,412, Japanese Unexamined Patent Application
Laid Open Nos. Shou 53-27033, Shou 54-58445, Shou 54-149634, Shou
54-64299, Shou 55-79450, Shou 55-144250, Shou 56-119132, Shou
61-295558, Shou 61-98353, Shou 63-295695, etc.) are preferable and
the aromatic tertiary amine compounds are particularly
preferable.
[0107] Further examples include, for example,
4,4'-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (abbreviated as NPD
below) having 2 fused aromatic rings in its molecule described in
U.S. Pat. Nos. 5,061,569, 4,4',4''-tris
(N-(3-methylphenyl)-N-phenylamino)triphenylamine (abbreviated as
MTDATA below) made by connecting three triphenylamine units to form
a star burst type, etc.
[0108] Besides, a compound with heterocyclic derivative structure
having a nitrogen atom expressed with a following general formula
disclosed in Japanese Registered Patent No. 03571977 is also
employable.
##STR00064##
[0109] In the formula, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5
and R.sub.6 each independently represents any one of a substituted
or unsubstituted alkyl group, a substituted or unsubstituted aryl
group, a substituted or unsubstituted aralkyl group or a
substituted or unsubstituted heterocyclic group. However, R.sub.1,
R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 may be the same with
or different from each other. Further, a couple of R.sub.1 and
R.sub.2, a couple of R.sub.3 and R.sub.4, a couple of R.sub.5 and
R.sub.6; or a couple of R.sub.1 and R.sub.6, a couple of R.sub.2
and R.sub.3, and a couple of R.sub.4 and R.sub.5 may bond each
other to form a fused ring structure.
[0110] Still further, a compound expressed with a following general
formula disclosed in US Patent Application Publication No.
2004/0113547 is also employable.
##STR00065##
[0111] In the formula, R1 to R6 are substituents, and preferably,
they each independently represents an electron withdrawing group
such as cyano group, nitro group, sulfonyl group, carbonyl group,
trifluoromethyl group, halogen atom, etc.
[0112] Further, except the above-mentioned aromatic
dimethylidene-based compound described as a material for the light
emitting layer, inorganic compound such as p-type silicon, p-type
silicon carbide or so is employable as the material for the hole
injecting layer. To form the hole injecting layer or the hole
transporting layer, a thin film may be formed from the material for
the hole injecting layer or the hole transporting layer,
respectively, in accordance with a well known process such as the
vacuum vapor deposition process, the spin coating process, the
casting process and the LB process. Although the thickness of the
hole injecting layer and the hole transporting layer is not
particularly limited, the thickness is usually from 5 nanometers to
5 .mu.m. It is preferable that the hole injecting layer or the hole
transporting layer comprises the compound of the present invention
in the hole transporting region. Further, the hole injecting layer
or the hole transporting layer may be composed of single layer
comprising one or more kind of those materials or may be laminated
with a hole injecting layer or a hole transporting layer each
comprising another kind of compound respectively.
[0113] In the organic EL device of the present invention, the
organic semiconductor layer assists to inject the holes or to
inject the electrons into the light emitting layer, and it is
preferable for the organic semiconductor layer to have a
conductance of 10.sup.-10 S/cm or greater. With regard to a
material for the organic semiconductor layer, electro-conductive
oligomers such as an oligomer having thiophene, an oligomer having
arylamine disclosed in Japanese Unexamined Patent Application
Laid-Open No. Hei 8-193191 and so on, electro-conductive dendrimers
such as a dendrimer having an arylamine dendrimer and so on are
employable.
(6) Electron Injection Layer
[0114] The electron injection layer in the organic EL device of the
present invention is a layer which assists injection of electrons
into the light emitting layer and exhibits a great mobility of
electrons. Among the electron injecting layers, an adhesion
improving layer is a layer made of a material exhibiting excellent
adhesion with the cathode. As the material for the electron
injecting layer, 8-hydroxyquinoline, metal complexes of derivatives
thereof and oxadiazole derivatives are preferable.
[0115] Examples of the 8-hydroxyquinoline and metal complexes of
derivatives thereof include metal chelate of oxinoid compounds
including chelate of oxine (in general, 8-quinolinol or
8-hydroxyquinoline).
[0116] For example, tris(8-quinolinol)aluminum (alq) can be
employed as the electron injecting material.
[0117] Further, examples of the oxadiazole delivertives include an
electron transfer compound shown as the following general
formulae:
##STR00066##
[0118] wherein Ar.sup.1, Ar.sup.2, Ar.sup.3, Ar.sup.5, Ar.sup.6 and
Ar.sup.9 each independently represents a substituted or
unsubstituted aryl group respectively, which may be the same with
or different from each other; Ar.sup.4, Ar.sup.7 and Ar.sup.8 each
independently represents a substituted or unsubstituted arylene
group, which may be the same with or different from each other.
[0119] Examples of aryl group include a phenyl group, a biphenyl
group, an anthranil group, a perilenyl group and a pyrenyl group.
Further, examples of the arylene group include a phenylene group, a
naphthylene group, a biphenylene group, an anthranylene group, a
perilenylene group, a pyrenylene group, etc. Furthermore, examples
of the substituent include an alkyl group having 1 to 10 carbon
atoms, an alkoxy group or a cyano group each having 1 to 10 carbon
atoms respectively, etc. With regard to the electron transfer
compound, those compounds having a thin film forming capability are
preferable.
[0120] Specific examples of the electron transfer compounds are
shown below:
##STR00067##
[0121] Further, it is known that another compound with heterocycles
having a nitrogen atom is preferable as the electron transporting
material.
[0122] Further, materials shown by following general formulae (E)
to (J) are employable for the electron injecting layer and the
electron transporting layer.
[0123] A heterocyclic derivative having a nitrogen atom represented
by a following general formula (E) or general formula (F):
##STR00068##
##STR00069##
[0124] In the general formulae (E) and (F), A.sup.1 to A.sup.3 each
independently represents a nitrogen atom or a carbon atom;
Ar.sup.1 represents a substituted or unsubstituted aryl group
having 6 to 60 ring carbon atoms or a substituted or unsubstituted
heteroaryl group having 3 to 60 ring carbon atoms; Ar.sup.2
represents a hydrogen atom, a substituted or unsubstituted aryl
group having 6 to 60 ring carbon atoms, a substituted or
unsubstituted heteroaryl group having 3 to 60 ring carbon atoms, a
substituted or unsubstituted alkyl group having 1 to 20 carbon
atoms, a substituted or unsubstituted alkoxy group having 1 to 20
carbon atoms or those divalent groups. However, at least one of
Ar.sup.1 or Ar.sup.2 represents a substituted or unsubstituted
fused ring group having 10 to 60 ring carbon atoms or a substituted
or unsubstituted monohetero fused ring group having 3 to 60 ring
carbon atoms; L.sup.1, L.sup.2 and L each independently represents
a single bond, a substituted or unsubstituted arylene group having
6 to 60 ring carbon atoms, a substituted or unsubstituted
heteroarylene group having 3 to 60 ring carbon atoms or a
substituted or unsubstituted fluorenylene group; R represents a
hydrogen atom, a substituted or unsubstituted aryl group having 6
to 60 ring carbon atoms, a substituted or unsubstituted heteroaryl
group having 3 to 60 ring carbon atoms, a substituted or
unsubstituted alkyl group having 1 to 20 carbon atoms, or a
substituted or unsubstituted alkoxy group having 1 to 20 carbon
atoms; n represents an integer of 0 to 5; when n is 2 or greater,
plural of R may be the same with or different from each other; and
adjacent couple of the plural of R may bond each other to form a
carbocyclic aliphatic ring or a carbocyclic aromatic ring.
[0125] A heterocyclic derivative having a nitrogen atom represented
by a following general formula (G):
HAr-L-Ar.sup.1-Ar.sup.2 (G)
wherein HAr represents a heterocyclic group having a nitrogen atom,
which has 3 to 40 carbon atoms and which may have a substituent; L
represents a single bond, an arylene group having 6 to 60 carbon
atoms and may have a substituent, a heteroarylene group having 3 to
60 carbon atoms and may have a substituent or a fluorenylene group
which may have a substituent; Ar.sup.1 represents a divalent
aromatic hydrocarbon group having 6 to 60 carbon atoms and may have
a substituent; and Ar.sup.2 represents an aryl group having 6 to 60
carbon atoms and may have a substituent or a heteroaryl group
having 3 to 60 carbon atoms and may have a substituent.
[0126] A silacyclopentadiene derivative represented by a following
general formula (H):
##STR00070##
wherein X and Y each independently represents a saturated or
unsaturated hydrocarbon group having 1 to 6 carbon atoms, an alkoxy
group, an alkenyloxy group, an alkynyloxy group, a hydroxy group, a
substituted or unsubstituted aryl group, a substituted or
unsubstituted hetero ring, or a structure forming a saturated or
unsaturated ring by bonding X and Y; R.sub.1 to R.sub.4 each
independently represents a hydrogen atom, a halogen atom, a
substituted or unsubstituted alkyl group having 1 to 6 carbon
atoms, an alkoxy group, an aryloxy group, a perfluoroalkyl group, a
perfluoro alkoxy group, an amino group, an alkyl carbonyl group, an
arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl
group, an azo group, an alkylcarbonyl oxy group, an arylcarbonyl
oxy group, alkoxycarbonyl oxy group, aryloxy carbonyl oxy group, a
sulfinyl group, a sulfonyl group, a sulfanilic group, a silyl
group, a carbamoyl group, an aryl group, a hetero ring group, an
alkenyl group, an alkynyl group, a nitro group, a formyl group, a
nitroso group, a formyloxy group, an isocyano group, a cyanate
group, an isocyanate group, a thiocyanate group, an isothiocyanate
group or a cyano group; or in an adjacent case, a structure made by
fusing a substituted or unsubstituted ring.
[0127] A borane derivative represented by a following general
formula (1):
##STR00071##
wherein R.sub.1 to R.sub.5 and Z.sub.2 each independently
represents a hydrogen atom, a saturated or unsaturated hydrocarbon
group, an aromatic group, a hetero ring group, substituted amino
group, a substituted boryl group, an alkoxy group or an aryloxy
group; X, Y and Z.sub.1 each independently represents a saturated
or unsaturated hydrocarbon group, an aromatic group, a heterocyclic
group, substituted amino group, an alkoxy group or an aryloxy
group; substituents of Z.sub.1 and Z.sub.2 may bonds each other to
form a fused ring; n represents an integer of 1 to 3, and when n is
2 or greater, plural of Z.sub.1 may be different from each other;
however, a case where n is 1, where X, Y and R.sub.2 are methyl
groups, and where R.sub.8 is a hydrogen atom or a substituted boryl
group and a case where n is 3 and where Z.sub.1 is a methyl group
are excluded.
##STR00072##
wherein Q.sub.1 and Q.sub.2 each independently represents a ligand
expressed by a following general formula (K), L represents a
halogen atom, a substituted or unsubstituted alkyl group, a
substituted or unsubstituted cycloalkyl group, a substituted or
unsubstituted aryl group, a substituted or unsubstituted
heterocyclic group, and --OR.sup.1 (R.sup.1 represents a hydrogen
atom, a substituted or unsubstituted alkyl group, a substituted or
unsubstituted cycloalkyl group, a substituted or unsubstituted aryl
group, a substituted or unsubstituted heterocyclic group) or a
ligand expressed by --O--Ga-Q.sup.3(Q.sup.4) wherein Q.sup.3 and
Q.sup.4 are the same as Q.sub.1 and Q.sub.2.
##STR00073##
wherein A.sup.1 and A.sup.2 each represents a fused 6 member-aryl
ring structure which may be substituted.
[0128] The metal-complex is powerfully characterized as n type
semiconductor, and its electron injection capability is exciting.
Besides, because generation energy in complex formation is small,
bonding property between the metal in the formed metal-complex and
the ligand becomes strong, and as a result, fluorescence quantum
efficiency as the light emitting material also becomes great.
[0129] Specific examples of substituents of rings A.sup.1 and
A.sup.2 each forming the ligand of general formula (K) include
halogen atoms such as chlorine atom, bromine atom, iodine atom and
fluorine atom; substituted or unsubstituted alkyl group such as
methyl group, ethyl group, propyl group, butyl group, s-butyl
group, t-butyl group, pentyl group, hexyl group, heptyl group,
octyl group, stearyl group, trichloromethyl group, etc.;
substituted or unsubstituted aryl group such as phenyl group,
naphthyl group, 3-methylphenyl group, 3-methoxyphenyl group,
3-fluorophenyl group, 3-trichloromethylphenyl group,
3-trifluoromethylphenyl group, 3-nitrophenyl group, etc.;
substituted or unsubstituted alkoxy group such as methoxy group,
n-butoxy group, t-butoxy group, trichloromethoxy group,
trifluoroethoxy group, pentafluoropropoxy group,
2,2,3,3-tetrafluoropropoxy group, 1,1,1,3,3,3-hexafluoro-2-propoxy
group, 6-(perfluoroethyl)hexyloxy group, etc.; substituted or
unsubstituted aryloxy group such as phenoxy group, p-nitrophenoxy
group, p-tert-butylphenoxy group, 3-fluorophenoxy group,
pentafluorophenyl group, 3-trifluoromethylphenoxy group, etc.;
substituted or unsubstituted alkylthio group such as methylthio
group, ethylthio group, tert-butylthio group, hexylthio group,
octylthio group, trifluoromethylthio group, etc.; substituted or
unsubstituted arylthio group such as phenylthio group,
p-nitrophenylthio group, p-tert-butylphenylthio group,
3-fluorophenylthio group, pentafluorophenylthio group,
3-trifluoromethylphenylthio group, etc.; mono- or di-substituted
amino group such as cyano group, nitro group, amino group,
methylamino group, diethylamino group, ethylamino group,
diethylamino group, dipropylamino group, dibutyl amino group,
diphenylamino group, etc.; acylamino-group such as
bis(acetoxymethyl)amino group, bis(acetoxyethyl)amino group,
bis(acetoxypropyl)amino group, bis(acetoxybutyl) amino group, etc.;
carbamoyl group such as hydroxy group, siloxy group, acyl group,
methylcarbamoyl group, dimethylcarbamoyl group, ethylcarbamoyl
group, diethylcarbamoyl group, a propylcarbamoyl group, butyl
carbamoyl group, a phenylcarbamoyl group, etc.; cycloalkyl group
such as carboxylic acid group, sulfonic acid group, imido group,
cyclopentane group, cyclohexyl group, etc.; aryl group such as
phenyl group, naphthyl group, biphenyl group, anthranil group,
phenanthryl group, fluorenyl group, pyrenyl group, etc.;
heterocyclic group such as pyridinyl group, pyrazinyl group,
pyrimidinyl group, pyridazinyl group, triazinyl group, indolinyl
group, quinolinyl group, acridinyl group, pyrrolidinyl group,
dioxanyl group, piperidinyl group, morpholidinyl group, piperazinyl
group, triazinyl group, carbazolyl group, furanyl group, thiophenyl
group, oxazolyl group, an oxadiazolyl group, a benzoxazolyl group,
a thiazolyl group, a thiadiazolyl group, benzothiazolyl group,
triazolyl group, imidazolyl group, benzimidazolyl group, pranyl
group, etc. Further, above-mentioned substituents may bond each
other to form further 6 membered aryl ring or heterocycle.
[0130] In the present invention, it is preferable that a reductive
dopant is added in either the electron transporting region or an
interfacial region between the cathode and the organic layer. The
reductive dopant used in the present invention is defined as a
substance which reduces the electron transporting compound.
Examples of the reductive dopant include at least one compound
selected from alkali metals, alkali metallic complexes, alkali
metal compounds, alkaline earth metals, alkaline earth metallic
complexes, alkaline earth metal compounds, rare earth metals, rare
earth metallic complexes and rare earth metal compounds. Examples
of the alkali metal compound, the alkaline earth metal compound and
the rare earth metal compound described above include oxides and
halides of the respective metals.
[0131] Examples of the preferable reductive dopant include at least
one alkali metal selected from a group consisting of Na (the work
function: 2.36 eV), K (the work function: 2.28 eV), Rb (the work
function: 2.16 eV) and Cs (the work function: 1.95 eV) or at least
one alkaline earth metals selected from a group consisting of Ca
(the work function: 2.9 eV), Sr (the work function: 2.0 to 2.5 eV)
and Ba (the work function: 2.52 eV); whose work function of 2.9 eV
or smaller is particularly preferable. Among those, more preferable
reductive dopants include at least one kind or more alkali metal
selected from the group consisting of K, Rb and Cs, the latter Rb
or Cs being farther more preferable and the last Cs being the most
preferable. Those alkali metals have particularly high reducing
capability, and only an addition of relatively small amount of them
into an electron injection region enables to achieve both
improvement of luminance and lifetime extension of the organic EL
device. Further, with regard to the reductive dopant with work
function of 2.9 eV or smaller, a combination of two or more kinds
of the alkali metal is also preferable, and particularly,
combinations containing Cs, for example, combinations of Cs and Na,
Cs and K, Cs and Rb, or Cs and Na and K are preferable. Containing
Cs in combination enables to reveal reducing capability
effectively, and the addition into the electron injection region
expects both improvement of luminance and lifetime extension of the
organic EL device.
[0132] In the organic EL device of the present invention, an
electron injecting layer comprising electric insulating material
and semiconductor may be disposed between the cathode and the
organic layer. The disposition of the electron injecting layer
enables to effectively prevent a leak of electric current and to
improve the electron injection property. It is preferable that at
least one metal compound selected from the group consisting of
alkali metal chalcogenides, alkaline earth metal chalcogenides,
alkali metal halides and alkaline earth metal halides is used as
the insulating material. It is preferable that the electron
injecting layer is constituted with the above alkali metal
chalcogenide since the electron injecting property can be improved.
Preferable examples of the alkali metal chalcogenide include
Li.sub.2O, LiO, Na.sub.2S and Na.sub.2Se. Preferable examples of
the alkaline earth metal chalcogenide include CaO, BaO, SrO, BeO,
BaS and CaSe. Preferable examples of the alkali metal halide
include LiF, NaF, KF, LiCl, KCl and NaCl. Preferable examples of
the alkaline earth metal halide include fluorides such as
CaF.sub.2, BaF.sub.2, SrF.sub.2, MgF.sub.2 and BeF.sub.2 and
halides other than the fluorides.
[0133] Examples of the semiconductor constituting the electron
transporting layer include oxides, nitrides and oxide nitrides
containing at least one element selected from Ba, Ca, Sr, Yb, Al,
Ga, In, Li, Na, Cd, Mg, Si, Ta, Sb and Zn, which are used singly or
in combination of two or more. It is preferable that the inorganic
compound constituting the electron transporting layer is in the
form of a fine crystalline or amorphous insulating thin film. When
the electron transporting layer is constituted with the above
insulating thin film, a more uniform thin film can be formed and
defective pixels such as dark spots can be decreased. Examples of
the inorganic compound include the alkali metal chalcogenides, the
alkaline earth metal chalcogenides, the alkali metal halides and
the alkaline earth metal halides which are described above.
(7) Cathode
[0134] As the cathode, an electrode substance such as metal, alloy,
electro-conductive compound and those mixture having a small work
function (4 eV or smaller) is employed. Examples of the electrode
substance include sodium, sodium-potassium alloy, magnesium,
lithium, magnesium-silver alloy, aluminum/aluminum oxide,
aluminum-lithium alloy, indium, rare earth metal, etc.
[0135] The cathode can be prepared by forming a thin film of the
electrode material described above in accordance with a process
such as the vapor deposition process and the sputtering
process.
[0136] When the light emitted from the light emitting layer is
obtained through the cathode, it is preferable that the cathode has
a transmittance of the emitted light greater than 10%.
[0137] It is also preferable that the sheet resistivity of the
cathode is several hundred .OMEGA./.quadrature. or smaller and that
the thickness of the cathode is, in general, selected in the range
of from 10 nanometers to 1 .mu.m and preferably in the range of
from 50 to 200 nanometers.
(8) Insulating Layer
[0138] In general, an organic EL device tends to form defects in
pixels due to leak and short circuit since an electric field is
applied to ultra-thin films. To prevent the formation of the
defects, a layer of an insulating thin film may be inserted between
the pair of electrodes.
[0139] Examples of the material employed for the insulating layer
include aluminum oxide, lithium fluoride, lithium oxide, cesium
fluoride, cesium oxide, magnesium oxide, magnesium fluoride,
calcium oxide, calcium fluoride, aluminum nitride, titanium oxide,
silicon oxide, germanium oxide, silicon nitride, boron nitride,
molybdenum oxide, ruthenium oxide and vanadium oxide.
[0140] Mixtures and laminates of the above compounds can also be
employed.
(9) Fabrication Example of an Organic EL Device
[0141] To fabricate an organic EL device of the present invention,
for example, an anode, a light emitting layer and, where necessary,
a hole injecting layer and an electron injecting layer are formed
in accordance with the aforementioned process using the
aforementioned materials, and a cathode is formed in the last step.
An organic EL device may be produced by forming the aforementioned
layers in the order reverse to that described above, i.e., a
cathode being formed in the first step and an anode in the last
step.
[0142] An embodiment of the process for fabricating an organic EL
device having a construction in which an anode, a hole injecting
layer, a light emitting layer, an electron injecting layer and a
cathode are disposed sequentially on a light-transmitting substrate
will be described in the following.
[0143] First, a thin film consisting of a desired electrode
substance, for example, a substance for the anode is formed over a
suitable substrate so as to finally achieve a film thickness of 1
.mu.m or thinner, preferably within a range from 10 nanometers to
200 nanometers in accordance with a vapor deposition method, a
sputtering method, etc. Then, a hole injecting layer is formed on
the anode. The hole injecting layer can be formed in accordance
with the vacuum vapor deposition process, the spin coating process,
the casting process or the LB process, as described above. The
vacuum vapor deposition process is preferable since a uniform film
can be easily obtained and the possibility of formation of pin
holes is small. When the hole injecting layer is formed in
accordance with the vacuum vapor deposition process, it is
preferable that the conditions in general are suitably selected in
the following ranges: temperature of the deposition source: 50 to
450.degree. C.; vacuum level: 10.sup.-7 to 10.sup.-3 torr;
deposition rate: 0.01 to 50 nanometers/second; temperature of the
substrate: -50 to 300.degree. C.; and film thickness: 5 nanometers
to 5 .mu.m; although the conditions of the vacuum vapor deposition
are different depending on the employed compound (the material for
the hole injecting layer) and the crystal structure and the
recombination structure of the hole injecting layer to be
formed.
[0144] Subsequently, the light-emitting layer is formed on the
hole-injecting layer formed above. Also the formation of the light
emitting layer can be made by forming the light emitting material
according to the present invention into a thin film in accordance
with the vacuum vapor deposition process, the sputtering process,
the spin coating process or the casting process. The vacuum vapor
deposition process is preferable because a uniform film can be
easily obtained and the possibility of formation of pinholes is
small. When the light-emitting layer is formed in accordance with
the vacuum vapor deposition process, in general, the conditions of
the vacuum vapor deposition process can be selected in the same
ranges as those described for the vacuum vapor deposition of the
hole-injecting layer although the conditions are different
depending on the used compound.
[0145] Next, the electron-injecting layer is formed on the
light-emitting layer formed above. Similarly to the hole injecting
layer and the light-emitting layer, it is preferable that the
electron-injecting layer is formed in accordance with the vacuum
vapor deposition process since a uniform film must be obtained. The
conditions of the vacuum vapor deposition can be selected in the
same ranges as those for the hole injecting layer and the
light-emitting layer.
[0146] Although the aromatic amine derivatives depend on that it is
contained in a light emitting layer or a hole transporting layer,
it may be vapor deposited together with other materials. In
addition, when the spin coating process is employed, it may be
contained therein by blending it with other materials.
[0147] In the last step, the cathode is formed on the
electron-injecting layer, and an organic EL device can be
fabricated.
[0148] The cathode is made of a metal and can be formed in
accordance with the vacuum vapor deposition process or the
sputtering process. It is preferable that the vacuum vapor
deposition process is employed in order to prevent the lower
organic layers from damages during the formation of the film.
[0149] In the above fabrication of the organic EL device, it is
preferable that the above layers from the anode to the cathode are
formed successively while the fabrication system is kept in a
vacuum after being evacuated.
[0150] The process for forming the layers in the organic EL device
of the present invention is not particularly limited. A
conventional process such as the vacuum vapor deposition process
and the spin coating process can be used. The organic thin film
layer comprising the compound represented by the foregoing general
formula (1) used in the organic EL device of the present invention
can be formed in accordance with the vacuum vapor deposition
process, the molecular beam epitaxy process (the MBE process) or,
using a solution prepared by dissolving the compound into a
solvent, in accordance with a conventional coating process such as
the dipping process, the spin coating process, the casting process,
the bar coating process and the roller coating process.
[0151] The thickness of each layer in the organic thin film layer
in the organic EL device of the present invention is not
particularly limited. In general, an excessively thin layer tends
to have defects such as pin holes, and an excessively thick layer
requires a high applied voltage resultantly in decreasing the
efficiency. Therefore, a thickness within the range of several
nanometers to 1 .mu.m is preferable.
[0152] The organic EL device which can be fabricated as described
above emits light when a DC voltage of 5 to 40 V is applied in the
condition that the anode is connected to a positive electrode (+)
and the cathode is connected to a negative electrode (-). When the
connection is reversed, no electric current is observed and no
light is emitted at all. When an alternating voltage is applied to
the organic EL device, the uniform light emission is observed only
in the condition that the polarity of the anode is positive and the
polarity of the cathode is negative. When an alternating voltage is
applied to the organic EL device, any type of wave shape can be
employed.
[0153] This invention will be described in further detail with
reference to Examples, which does not limit the scope of the
invention.
EXAMPLE
(A) Synthesis Example 1
Synthesis of Intermediate Product
[0154] (A-1) Synthesis of 2,7-dibromo-9,10-dihydrophenanthrene
[0155] Dissolving 30.0 g of 9,10-dihydrophenanthrene into 200
milliliter of (MeO).sub.3PO, and a solution prepared by mixing 56.7
g of bromine with 100 milliliter of (MeO).sub.3PO was dripped into
the resultant solution contained in a flask. Shading the flask from
light, the reacted solution was stirred for 8 hours. As a result, a
white precipitation generated. After the completion of the
reaction, the white precipitation in the reacted solution was
separated by filtration. After washing the resultant crystal with a
use of methanol, it was vacuum dried and 32.7 g of
2,7-dibromo-9,10-dihydrophenanthrene was obtained as white
crystal.
(A-2) Synthesis of 2,7-dibromophenanthrene
[0156] Preparing 32.7 g of 2,7-dibromo-9,10-dihydrophenanthrene,
24.1 g of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and 500
milliliter of benzene as a mixture solution, the solution was
refluxed with heating under an ambient atmosphere of argon gas for
64 hours. The reacted solution was cooled down to a room
temperature, and further filtered. Concentrating the filtrate by
means of an evaporator, the residue was washed with a use of
methanol. After refining the filtered product by means of a short
column, the refined product was recrystallized with a use of
toluene and as a result, 15.5 g of 2,7-dibromophenanthrene was
obtained as colorless needle crystals.
(B) Synthesis Example 2
Synthesis of Phenanthreneamine Derivative
##STR00074## ##STR00075## ##STR00076## ##STR00077##
##STR00078##
[0157] (B-1) Synthesis of Compound 1
[0158] Adding 0.66% by weight toluene solution in an amount of 100
microliter prepared by dissolving tri-t-butylphosphine into a mixed
solution prepared by dissolving 3.36 g of 2,7-dibromophenanthrene,
5.26 g of N-phenyl-1-naphthylamine, 183 milligram of
tris(dibenzylideneacetone)dipalladium (O) and 1.34 g of
t-butoxysodium into toluene in an amount of 100 milliliter, the
resultant solution was refluxed with heating for 5 hours. After
cooling the resultant solution down to a room temperature, the
precipitated solid was separated by filtration. The resultant solid
was washed with uses of methanol, water, methanol and toluene
sequentially and further, it was dried under a reduced pressure.
After dissolving the solid in hot toluene, it was filtered while
heating and then, cooling down to a room temperature, a crystal
resultantly precipitated. The crystal was separated by filtration
and re-crystallizing with a use of toluene, 3.26 g of pale greenish
white crystal was obtained. As a result of mass spectrum analysis,
the pale greenish white crystal was identified as the aimed
substance, and it was recognized that m/e=612 for molecular weight
of 612.26.
(B-2) Synthesis of Compound 2
[0159] (1) Synthesis of
N-(4-bromophenyl)-N-phenyl-1-naphthylamine
[0160] Adding 17.6 g of N,N'-dimethylethylenediamine into a
solution prepared by mixing 21.9 g of N-phenyl-1-naphthylamine,
28.2 g of 4-bromoiodobenzene, 14.4 g of t-butoxysodium, 3.81 g of
copper powder and 100 milliliter of xylene, the resultant solution
was refluxed with heating under ambient atmosphere of argon gas for
24 hours. After cooling the resultant solution down to a room
temperature, the solution was filtered and insolubles were removed
followed by concentrating the filtrate. Refining the residue by
means of a silicagel column chromatography, 25.4 g of
N-(4-bromophenyl)-N-phenyl-1-naphthylamine was obtained.
(2) Synthesis of 4-(N-1-naphthyl-N-phenylamino)phenylboronic
Acid
[0161] Under an ambient atmosphere of argon gas, cooling a solution
prepared by mixing 18.7 g of
N-(4-bromophenyl)-N-phenyl-1-naphthylamine, 100 milliliter of dried
ethyl ether and 100 milliliter of dried toluene down to a
temperature of -78.degree. C., a hexane solution of 1.6M normal
butyllithium in an amount 32.8 milliliter was dripped into the
cooled solution. The reacted solution was stirred for 1 hour while
warming up to a temperature of 0.degree. C. Cooling the reacted
solution down to the temperature of -78.degree. C. again, a
solution prepared by dissolving 23.5 g of boric acid triisopropyl
into dried ether in an amount of 50 milliliter was dripped down to
the cooled solution. The resultant solution was further stirred at
a room temperature for 5 hours. Adding 100 milliliter of 1 N
hydrochloric acid and after stirring the resultant solution for 1
hour, a water layer was removed. After drying an organic layer with
a use of magnesium sulfate, the solvent was distillated away under
a reduced pressure. Refining a resultant solid by means of a
silicagel column chromatography, 10.2 g of
4-(N-1-naphthyl-N-phenylamino)phenylboronic acid was obtained.
(3) Synthesis of
2-bromo-7-(N-1-naphthyl-N-phenylamino)phenanthrene
[0162] Under an atmospheric argon gas flow, 13.7 g of
N-phenyl-1-naphthylamine, 21.0 g of 2,7-dibromophenanthrene, 13.0 g
of potassium carbonate, 0.400 g of copper powder and 40 milliliter
of decalin were prepared as a mixed solution, and the solution
reacted at a temperature of 200.degree. C. for 6 days.
[0163] After the reaction, the resultant solution was filtered
while heating and an insoluble substance was washed with a use of
toluene, followed by concentration together with the filtrate.
Adding 30 milliliter of toluene onto the residue, precipitated
crystal was removed by filtration, and the filtrate was
concentrated. Subsequently adding 100 milliliter of methanol onto
the residue, a supernatant liquid was disposed as waste water after
stirring and then, further adding 30 milliliter of methanol, a
supernatant liquid was disposed as waste water again after
stirring, followed by a column refinement and as a result, yellow
powder was obtained. Dissolving the yellow powder into 15
milliliter of toluene while heating, and adding 15 milliliter of
hexane, the resultant solution was cooled down. Separating a
precipitated crystal by filtration, 13.4 g of
2-bromo-7-(N-1-naphthyl-N-phenylamino) phenanthrene was
obtained.
(4) Synthesis of Compound 2
[0164] Under an atmospheric argon gas flow, 5.00 g of
2-bromo-7-(N-1-naphthyl-N-phenylamino)phenanthrene, 4.29 g of
4-(N-1-naphthyl-N-phenylamino) phenylboronic acid, 243 milligram of
tetrakis(triphenylphosphine)palladium (O), 40 milliliter of toluene
and 20 milliliter of 2M sodium carbonate aqueous solution were
prepared as a mixed solution, and the solution was refluxed with
heating for 8 hours. After the completion of the reaction, the
solution was filtered. After washing a solid obtained by filtering
with uses of water and methanol, further re-crystallizing with a
use of toluene, 3.12 g of pale greenish white crystal was obtained.
As a result of mass spectrum analysis, the pale greenish white
crystal was identified as the aimed substance, and it was
recognized that m/e=688 for molecular weight of 688.29.
(B-3) Synthesis of Compound 3
[0165] Compound 3 was synthesized in the same manner as Compound 2
except that N-biphenyl aniline was employed instead of
N-phenyl-1-naphthylamine. As a result of mass spectrum analysis,
the Compound 3 was identified as the aimed substance, and it was
recognized that m/e=740 for molecular weight of 740.32.
(B-4) Synthesis of Compound 4
[0166] Compound 4 was synthesized in the same manner as Compound 2
except that 2,7-dibromophenanthrene was employed instead of
2-bromo-7-(N-1-naphthyl-N-phenylamino)phenanthrene. As a result of
mass spectrum analysis, the Compound 4 was identified as the aimed
substance, and it was recognized that m/e=764 for molecular weight
of 764.32.
(B-5) Synthesis of Compound 5
[0167] Adding 0.66% by weight toluene solution in an amount of 200
microliter prepared by dissolving tri-t-butylphosphine into a mixed
solution prepared by dissolving 10.4 g of
2-bromo-7-(N-1-naphthyl-N-phenylamino)phenanthrene, 0.930 g of
aniline, 366 milligram of tris(dibenzylideneacetone)dipalladium (O)
and 2.68 g of t-butoxysodium into toluene in an amount of 200
milliliter, the resultant solution was refluxed with heating for 5
hours. After cooling the resultant solution down to a room
temperature, the precipitated solid was separated by filtration.
The resultant solid was washed with uses of methanol, water,
methanol and toluene sequentially and further, it was dried under a
reduced pressure. After dissolving the solid in hot toluene, it was
filtered while heating and then, cooling down to a room
temperature, a crystal resultantly precipitated. The crystal was
separated by filtration and re-crystallizing with a use of toluene,
7.26 g of pale greenish white crystal was obtained. As a result of
mass spectrum analysis, the pale greenish white crystal was
identified as the aimed substance, and it was recognized that
m/e=879 for molecular weight of 879.36.
(B-6) Synthesis of Compound 6
[0168] Compound 6 was synthesized in the same manner as Compound 5
except that 2-bromo-7-[N,N-bis(4-biphenyl)amino]phenanthrene was
employed instead of
2-bromo-7-(N-1-naphthyl-N-phenylamino)phenanthrene. As a result of
mass spectrum analysis, the Compound 6 was identified as the aimed
substance, and it was recognized that m/e=1083 for molecular weight
of 1083.46.
(B-7) Synthesis of Compound 7
[0169] Compound 7 was synthesized in the same manner as Compound 5
except that 2-bromo-7-[N-(4-biphenyl)-N-phenylamino]phenanthrene
was employed instead of
2-bromo-7-(N-1-naphthyl-N-phenylamino)phenanthrene. As a result of
mass spectrum analysis, the Compound 7 was identified as the aimed
substance, and it was recognized that m/e=931 for molecular weight
of 931.39.
(B-8) Synthesis of Compound 8
[0170] (1) Synthesis of
4-bromo-4'-(N-1-naphthyl-N-phenylamino)biphenyl
[0171] Under an atmospheric argon gas flow, 13.7 g of
N-phenyl-1-naphthylamine, 19.5 g of 4,4'-dibromobiphenyl, 13.0 g of
potassium carbonate, 0.400 g of copper powder and 40 milliliter of
decalin were prepared as a mixed solution, and the solution reacted
at a temperature of 200.degree. C. for 6 days. After the reaction,
the resultant solution was filtered while heating and an insoluble
substance was washed with a use of toluene, followed by
concentration together with the filtrate. Adding 30 milliliter of
toluene onto the residue, precipitated crystal was removed by
filtration, and the filtrate was concentrated. Subsequently adding
100 milliliter of methanol onto the residue, a supernatant liquid
was disposed as waste water after stirring and then, further adding
30 milliliter of methanol, a supernatant liquid was disposed as
waste water again after stirring, followed by a column refinement
and as a result, yellow powder was obtained. Dissolving the yellow
powder into 15 milliliter of toluene while heating, and adding 15
milliliter of hexane, the resultant solution was cooled down.
Separating a precipitated crystal by filtration, 13.4 g of
4-bromo-4'-(N-1-naphthyl-N-phenylamino)biphenyl was obtained.
(2) Synthesis of N,N'-diphenyl-N-1-naphthylbenzidine
[0172] Adding 0.66% by weight toluene solution in an amount of 100
microliter prepared by dissolving tri-t-butylphosphine into a mixed
solution prepared by dissolving 4.50 g of
4-bromo-4'-(N-1-naphthyl-N-phenylamino)biphenyl, 1.11 g of aniline,
183 milligram of tris(dibenzylideneacetone)dipalladium(O) and 1.35
g of t-butoxysodium into toluene in an amount of 100 milliliter,
the resultant solution was stirred at a room temperature for 5
hours. After the completion of the reaction, the solution was
filtered with a use of celite and the filtrate was extracted with
toluene. Concentrating the filtrate under a reduced pressure, the
resultant crude product was refined by means of a column and as a
result, 3.50 g of pale yellow powder was obtained
(3) Synthesis of Compound 8
[0173] Adding 0.66% by weight toluene solution in an amount of 50
microliter prepared by dissolving tri-t-butylphosphine into a mixed
solution prepared by dissolving 2.37 g of
2-bromo-7-(N-1-naphthyl-N-phenylamino)phenanthrene, 2.25 g of
N,N'-diphenyl-N-1-naphthylbenzidine, 91.5 milligram of
tris(dibenzylideneacetone)dipalladium(O) and 0.670 g of
t-butoxysodium into toluene in an amount of 50 milliliter, the
resultant solution was refluxed with heating for 5 hours. After
cooling the resultant solution down to a room temperature, the
precipitated solid was separated by filtration. The resultant solid
was washed with uses of methanol, water, methanol and toluene
sequentially and further, it was dried under a reduced pressure.
After dissolving the solid in hot toluene, it was filtered while
heating and then, cooling down to a room temperature, a crystal
resultantly precipitated. The crystal was separated by filtration
and re-crystallizing with a use of toluene, 3.26 g of pale greenish
white crystal was obtained. As a result of mass spectrum analysis,
the pale greenish white crystal was identified as the aimed
substance, and it was recognized that m/e=855 for molecular weight
of 855.36.
(B-9) Synthesis of Compound 9
[0174] (1) Synthesis of
4-bromo-4''-(N-1-naphthyl-N-phenylamino)-p-terphenyl
[0175] Under an atmospheric argon gas flow, 13.7 g of
N,N-diphenylamine, 24.3 g of 4,4''-dibromo-p-terphenyl, 13.0 g of
potassium carbonate, 0.400 g of copper powder and 40 milliliter of
decalin were prepared as a mixed solution, and the solution reacted
at a temperature of 200.degree. C. for 6 days.
[0176] After the reaction, the resultant solution was filtered
while heating and an insoluble substance was washed with a use of
toluene, followed by concentration together with the filtrate.
Adding 30 milliliter of toluene onto the residue, precipitated
crystal was removed by filtration, and the filtrate was
concentrated. Subsequently adding 100 milliliter of methanol onto
the residue, a supernatant liquid was disposed as waste water after
stirring and then, further adding 30 milliliter of methanol, a
supernatant liquid was disposed as waste water again after
stirring, followed by a column refinement and as a result, yellow
powder was obtained. Dissolving the yellow powder into 15
milliliter of toluene while heating, and adding 15 milliliter of
hexane, the resultant solution was cooled down. Separating a
precipitated crystal by filtration, 13.4 g of
4-bromo-4''-diphenylamino-p-terphenyl was obtained.
(2) Synthesis of
2-(N-1-naphthyl-N-phenylamino)-7-(N-phenylamino)phenanthrene
[0177] Adding 0.66% by weight toluene solution in an amount of 100
microliter prepared by dissolving tri-t-butylphosphine into a mixed
solution prepared by dissolving 4.74 g of
4-bromo-4'-(N-1-naphthyl-N-phenylamino)biphenyl, 1.11 g of aniline,
183 milligram of tris(dibenzylideneacetone)dipalladium(O) and 1.35
g of t-butoxysodium into toluene in an amount of 100 milliliter,
the resultant solution was stirred at a room temperature for 5
hours. After the completion of the reaction, the solution was
filtered. The resultant solid was washed with uses of methanol,
water, methanol and toluene sequentially and further, it was dried
under a reduced pressure and as a result, 3.50 g of gray powder
(crude product) was obtained.
(3) Synthesis of Compound 9
[0178] Adding 0.66% by weight toluene solution in an amount of 50
microliter prepared by dissolving tri-t-butylphosphine into a mixed
solution prepared by dissolving 2.63 g of
4-bromo-4''-diphenylamino-p-terphenyl, 2.91 g of
2-(N-1-naphthyl-N-phenylamino)-7-(N-phenylamino)phenanthrene, 91.5
milligram of tris(dibenzylideneacetone)dipalladium(O) and 0.670 g
of t-butoxysodium into toluene in an amount of 50 milliliter, the
resultant solution was refluxed with heating for 5 hours. After
cooling the resultant solution down to a room temperature, the
precipitated solid was separated by filtration. The resultant solid
was washed with uses of methanol, water, methanol and toluene
sequentially and further, it was dried under a reduced pressure.
After dissolving the solid into hot toluene, it was filtered while
heating and then, cooling down to a room temperature, a crystal
resultantly precipitated. The crystal was separated by filtration
and re-crystallizing with a use of toluene, 2.26 g of pale greenish
white crystal was obtained. As a result of mass spectrum analysis,
the pale greenish white crystal was identified as the aimed
substance, and it was recognized that m/e=931 for molecular weight
of 931.39.
(B-10) Synthesis of Compound 10
[0179] (1) Synthesis of 2,7-bis(N-anilino)phenanthrene
[0180] Adding 0.66% by weight toluene solution in an amount of 100
microliter prepared by dissolving tri-t-butoxysodium into a mixed
solution prepared by dissolving 3.36 g of 2,7-dibromophenanthrene,
1.11 g of aniline, 183 milligram of
tris(dibenzylideneacetone)dipalladium(O) and 1.34 g of
t-butylphosphine into toluene in an amount of 100 milliliter, the
resultant solution was refluxed with heating for 5 hours. After
cooling the resultant solution down to a room temperature, the
precipitated solid was separated by filtration. The resultant solid
was washed with uses of methanol, water, methanol and toluene
sequentially and further, it was dried under a reduced pressure and
as a result, 3.26 g of gray solid was obtained.
(2) Synthesis of Compound 10
[0181] Adding 0.66% by weight toluene solution in an amount of 100
microliter prepared by dissolving tri-t-butylphosphine into a mixed
solution prepared by dissolving 1.80 g of
2,7-bis(N-anilino)phenanthrene, 4.40 g of
4-bromo-4'-(N,N-diphenylamino)biphenyl, 183 milligram of
tris(dibenzylideneacetone)dipalladium(O) and 1.35 g of
t-butoxysodium into toluene in an amount of 50 milliliter, the
resultant solution was refluxed with heating for 5 hours. After
cooling the resultant solution down to a room temperature, the
precipitated solid was separated by filtration. The resultant solid
was washed with uses of methanol, water, methanol and toluene
sequentially and further, it was dried under a reduced pressure.
After dissolving the solid into hot toluene, it was filtered while
heating and then, cooling down to a room temperature, a crystal
resultantly precipitated. The crystal was separated by filtration
and re-crystallizing with a use of toluene, 2.20 g of pale greenish
white crystal was obtained. As a result of mass spectrum analysis,
the pale greenish white crystal was identified as the aimed
substance, and it was recognized that m/e=998 for molecular weight
of 998.43.
(B-11) Synthesis of Compound 11
[0182] Compound 11 was synthesized in the same manner as Compound
10 except that 4-bromotriphenyl amine was employed instead of
4-bromo-4'-(N,N-diphenylamino)biphenyl. As a result of mass
spectrum analysis, the Compound 11 was identified as the aimed
substance, and it was recognized that m/e=846 for molecular weight
of 846.37.
Example 1
[0183] A glass substrate (manufactured by GEOMATEC Company) of 25
mm.times.75 mm.times.1.1 mm thickness having an ITO transparent
electrode was cleaned by application of ultrasonic wave in
isopropyl alcohol for 5 minutes and then by exposure to ozone
generated by ultraviolet light for 30 minutes. The glass substrate
having the transparent electrode lines which had been cleaned was
attached to a substrate holder of a vacuum vapor deposition
apparatus. On the surface of the cleaned substrate at the side
having the transparent electrode, a film of Compound 1 having a
thickness of 80 nanometers was formed in accordance with a
resistance heating vapor deposition process so that the formed film
covered the transparent electrode. The formed film of Compound 1
worked as the hole injecting layer. Over the formed film of
Compound 1,9-(2-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene
(abbreviated as AN-1 below) having a thickness of 40 nanometers was
further formed in accordance with the resistance heating vapor
deposition process. At the same time, the following amine compound
D-1 having styryl group as light emitting molecule was deposited
with a weight ratio of AN-1: D-1=40:2. The formed film worked as a
light emitting layer. On the film formed above, a film of Alq
having a thickness of 10 nanometers was formed. The formed film
worked as an electron injecting layer. Thereafter, Li (the source
of lithium: manufactured by SAES GETTERS Company) as a reductive
dopant and Alq were binary vapor deposited and an Alq:Li film (film
thickness: 10 nanometers) was formed as the electron injecting
layer (or the cathode). On the Alq:Li film, metallic aluminum was
deposited to form a metal cathode and an organic El device was
fabricated.
##STR00079##
Examples 2 to 10
[0184] Organic EL devices were fabricated in accordance with the
same procedures as those conducted in Example 1 except that
Compound 1 was replaced with Compounds 2 to 10 respectively.
Comparative Examples 1 to 7
[0185] Organic EL devices were fabricated in accordance with the
same procedures as those conducted in Example 1 except that
Compound 1 was replaced with following Compounds (A) to (G)
respectively.
##STR00080## ##STR00081## ##STR00082##
[0186] Table 1 shows performance measurement results about the
organic EL devices each fabricated in Examples 1 to 10 and
Comparative Examples 1 to 7 respectively.
TABLE-US-00001 TABLE 1 Current Current Density Efficiency Color of
Half Lifetime (mA/cm.sup.2) (cd/A) Light (hours) Compound @ 5 V @
100 cd/m.sup.2 Emission @1000 cd/m.sup.2 Example 1 Compound 1 3.12
6.4 Blue 3500 Example 2 Compound 2 3.21 6.5 Blue 3500 Example 3
Compound 3 3.18 6.6 Blue 3500 Example 4 Compound 4 3.05 6.4 Blue
3500 Example 5 Compound 5 3.31 6.8 Blue 4000 Example 6 Compound 6
3.30 6.3 Blue 4000 Example 7 Compound 7 3.30 6.4 Blue 4000 Example
8 Compound 8 3.21 6.7 Blue 4000 Example 9 Compound 9 3.40 6.6 Blue
4000 Example 10 Compound 10 3.50 6.6 Blue 3500 Co. Example 1
Compound (A) 2.32 5.8 Blue 1500 Co. Example 2 Compound (B) 2.44 5.1
Blue 2000 Co. Example 3 Compound (C) 2.54 6.2 Blue 1500 Co. Example
4 Compound (D) 3.12 5.8 Blue 1000 Co. Example 5 Compound (E) 3.11
6.2 Blue 1000 Co. Example 6 Compound (F) 2.01 6.0 Blue 2000 Co.
Example 7 Compound (G) 2.18 6.1 Blue 2000 Notification: In the
Table 1, "Co. Example" means "Comparative Example".
[0187] Referring the Table 1, it verifies that an employment of the
compound in the present invention for a hole injecting layer
provides favorable hole injection property, an enhanced current
efficiency of light emission. Further, while maintaining the
favorable hole injection property and the enhanced current
efficiency of light emission, it also provides a prolonged
lifetime. Still further, it also verifies that the structure of
2,7-phenanthrene diamine is more remarkably effective than the
structure of 9-phenanthreneamine (Comparative examples 6 and
7).
Example 11
[0188] A glass substrate (manufactured by GEOMATEC Company) of 25
mm.times.75 mm.times.1.1 mm thickness having an ITO transparent
electrode was cleaned by application of ultrasonic wave in
isopropyl alcohol for 5 minutes and then by exposure to ozone
generated by ultraviolet light for 30 minutes. The glass substrate
having the transparent electrode lines which had been cleaned was
attached to a substrate holder of a vacuum vapor deposition
apparatus. On the surface of the cleaned substrate at the side
having the transparent electrode, a film of Compound 11 having a
thickness of 60 nanometers was formed in accordance with a
resistance heating vapor deposition process so that the formed film
covered the transparent electrode. The formed film of Compound 11
worked as the first hole injecting layer (the hole transporting
layer). Subsequent to the film-forming of the film of Compound 11,
a film of 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (referred
to as a "film of NPD", hereunder) having a thickness of 20
nanometers was formed over the film of Compound 11 in accordance
with the resistance heating vapor deposition process. The formed
film of NPD worked as the second hole injecting layer (the hole
transporting layer). Subsequent to the film-forming of the film of
NPD, a film of AN-1 having a thickness of 40 nanometers was further
formed over the film of NPD in accordance with the resistance
heating vapor deposition process. At the same time, the amine
compound D-1 was vapor deposited as a light emitting molecule with
an weight ratio of AN-1:D-1=40:2. The formed film worked as a light
emitting layer. On the film formed above, a film of Alq having a
thickness of 10 nanometers was formed. The formed film worked as an
electron injecting layer. Thereafter, Li (the source of lithium:
manufactured by SAES GETTERS Company) as a reductive dopant and Alq
were binary vapor deposited and an Alq:Li film (film thickness: 10
nanometers) was formed as the electron injecting layer (or the
cathode). On the Alq:Li film, metallic aluminum was vapor deposited
to form a metal cathode and an organic El device was
fabricated.
Comparative Example 8
[0189] An organic EL device was fabricated in accordance with the
same procedure as conducted in Example 11 except that Compound 11
was replaced with a following Compound (E).
##STR00083##
[0190] Table 2 shows performance measurement results about the
organic EL devices each fabricated in Example 11 and Comparative
Example 8 respectively.
TABLE-US-00002 TABLE 2 Current Current Half Density Efficiency
Color of Lifetime (mA/cm.sup.2) (cd/A) Light (hours) Compound @ 5 V
@100 cd/m.sup.2 Emission @1000 cd/m.sup.2 Example 11 Compound 11
3.01 6.6 Blue 5500 Co. Example 8 Compound (E) 2.32 6.2 Blue 5200
Notification: In the Table 2, "Co. Example" also means "Comparative
Example".
[0191] An employment of the compound in the present invention for a
hole injecting layer provides favorable hole injection property, an
enhanced current efficiency of light emission and a prolonged
lifetime.
[0192] As the detailed explanation above, because the organic
electroluminescence device of the present invention has an organic
thin film layer comprising materials containing a substituted or
unsubstituted aromatic amine derivative and a material for the
organic EL device both having a phenanthrenylene group in their
coupling group, it reveals a prolonged lifetime, favorable hole
injection property and an enhanced current efficiency of light
emission as compared with the devices employing conventional
compounds or materials for the organic EL device.
INDUSTRIAL APPLICABILITY
[0193] The organic EL device using the aromatic amine derivative
and the material for the organic EL device according to the present
invention exhibits an enhanced current efficiency of light emission
and emits blue light with a prolonged lifetime. Accordingly, it is
extremely useful as highly practical organic EL device.
Resultantly, the EL device is useful as a flat panel light emitting
member for a wall-hanging type television or as a light source of
backlight and the like for display devices.
* * * * *