U.S. patent application number 16/317444 was filed with the patent office on 2019-10-10 for organic light emitting device.
The applicant listed for this patent is LG CHEM, LTD.. Invention is credited to Minwoo CHOI, Min Seung CHUN, Boon Jae JANG, Hyeon Soo JEON, Sang Young JEON.
Application Number | 20190312223 16/317444 |
Document ID | / |
Family ID | 63676342 |
Filed Date | 2019-10-10 |
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United States Patent
Application |
20190312223 |
Kind Code |
A1 |
CHUN; Min Seung ; et
al. |
October 10, 2019 |
ORGANIC LIGHT EMITTING DEVICE
Abstract
The present invention provides an organic light emitting device
including a light emitting layer comprising a compound represented
by Chemical Formula 1 and an electron transport layer comprising a
compound represented by Chemical Formula 2, and having improved
driving voltage and efficiency.
Inventors: |
CHUN; Min Seung; (Daejeon,
KR) ; JEON; Sang Young; (Daejeon, KR) ; JANG;
Boon Jae; (Daejeon, KR) ; CHOI; Minwoo;
(Daejeon, KR) ; JEON; Hyeon Soo; (Daejeon,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG CHEM, LTD. |
Seoul |
|
KR |
|
|
Family ID: |
63676342 |
Appl. No.: |
16/317444 |
Filed: |
January 3, 2018 |
PCT Filed: |
January 3, 2018 |
PCT NO: |
PCT/KR2018/000121 |
371 Date: |
January 11, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 51/0045 20130101;
H01L 51/0067 20130101; H01L 51/00 20130101; H01L 51/50 20130101;
H01L 51/0085 20130101; C09K 11/06 20130101; H01L 51/0059 20130101;
H01L 51/0072 20130101; H01L 51/0052 20130101; H01L 51/5072
20130101; H01L 51/0073 20130101; H01L 51/5016 20130101; H01L
51/5056 20130101; H01L 51/5203 20130101 |
International
Class: |
H01L 51/50 20060101
H01L051/50; C09K 11/06 20060101 C09K011/06; H01L 51/52 20060101
H01L051/52; H01L 51/00 20060101 H01L051/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2017 |
KR |
10-2017-0040552 |
Claims
1. An organic light emitting device comprising: a first electrode;
a hole transport layer, a light emitting layer; an electron
transport layer, and a second electrode, wherein the light emitting
layer comprises a compound represented by Chemical Formula 1 and
the electron transport layer comprises a compound represented by
Chemical Formula 2: ##STR00036## wherein, in Chemical Formula 1,
Ar.sub.1 and Ar.sub.2 are the same as or different from each other,
and each independently a substituted or unsubstituted C.sub.6-60
aryl, l and p are each independently an integer of 0 to 4, m and o
are each independently an integer of 0 to 2, R.sub.1 to R.sub.4 are
the same as or different from each other, and each independently
hydrogen; a substituted or unsubstituted C.sub.6-60 aryl; or
C.sub.2-60 heteroaryl containing one or more heteroatoms each
independently selected from the group consisting of N, O and S; or
R.sub.1 and R.sub.2, or R.sub.3 and R.sub.4 bond to each other to
form a substituted or unsubstituted C.sub.6-60 aromatic ring,
##STR00037## wherein, in Chemical Formula 2, X.sub.1 to X.sub.3 are
the same as or different from each other, and each independently N,
or CH, provided that at least one of X.sub.1 to X.sub.3 is N,
Ar.sub.4 and Ar.sub.5 are the same as or different from each other,
and each independently a substituted or unsubstituted C.sub.6-60;
or C.sub.2-60 heteroaryl containing one or more heteroatoms each
independently selected from the group consisting of N, O and S,
each L is the same as or different from each other, and each
independently a substituted or unsubstituted C.sub.6-60 arylene; or
C.sub.2-60 heteroarylene containing one or more heteroatoms each
independently selected from the group consisting of N, O, S and P,
and Ar.sub.6 is a substituted or unsubstituted C.sub.6-60 arylene;
or C.sub.2-60 heteroarylene containing one or more heteroatoms each
independently selected from the group consisting of N, O and S.
2. The organic light emitting device of claim 1, wherein Ar.sub.1
and Ar.sub.2 are the same as or different from each other, and each
independently phenyl, biphenylyl, naphthyl, phenanthrenyl, or
terphenyl.
3. The organic light emitting device of claim 1, wherein R.sub.1 to
R.sub.4 are the same as or different from each other, and each
independently hydrogen, or carbazolyl substituted with phenyl.
4. The organic light emitting device of claim 1, wherein the
compound represented by Chemical Formula 1 is any one selected from
the group consisting of: ##STR00038## ##STR00039## ##STR00040##
##STR00041## ##STR00042##
5. The organic light emitting device of claim 1, wherein X.sub.1 to
X.sub.3 are N.
6. The organic light emitting device of claim 1, wherein Ar.sub.4
and Ar.sub.5 are the same as or different from each other, and each
independently phenyl, phenyl substituted with methyl, or
naphthyl.
7. The organic light emitting device of claim 1, wherein L is
phenylene.
8. The organic light emitting device of claim 1, wherein Ar.sub.6
is phenylene, naphthylene, phenanthrenylene, dimethylfluorenylene,
dibenzofuranylene, or dibenzothiophenylene.
9. The organic light emitting device of claim 1, wherein the
compound represented by Chemical Formula 2 is any one selected from
the group consisting of: ##STR00043## ##STR00044## ##STR00045##
##STR00046## ##STR00047## ##STR00048## ##STR00049##
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 10-2017-0040552 filed on Mar. 30,
2017 with the Korean Intellectual Property Office, the disclosure
of which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to an organic light emitting
device having improved driving voltage and efficiency.
BACKGROUND ART
[0003] In general, an organic light emitting phenomenon refers to a
phenomenon where electric energy is converted into light energy by
using an organic material. The organic light emitting device using
the organic light emitting phenomenon has characteristics such as a
wide viewing angle, an excellent contrast, a fast response time, an
excellent luminance, driving voltage and response speed, and thus
many studies have proceeded.
[0004] The organic light emitting device generally has a structure
which comprises an anode, a cathode, and an organic material layer
interposed between the anode and the cathode. The organic material
layer frequently have a multilayered structure that comprises
different materials in order to enhance efficiency and stability of
the organic light emitting device, and for example, the organic
material layer may be formed of a hole injection layer, a hole
transport layer, a light emitting layer, an electron transport
layer, an electron injection layer and the like. In the structure
of the organic light emitting device, if a voltage is applied
between two electrodes, the holes are injected from an anode into
the organic material layer and the electrons are injected from the
cathode into the organic material layer, and when the injected
holes and the electrons meet each other, an exciton is formed, and
light is emitted when the exciton falls to a ground state
again.
[0005] In the organic light emitting device as described above,
there is a continuing demand for developing an organic light
emitting device having improved driving voltage and efficiency.
PRIOR ART LITERATURE
Patent Literature
[0006] (Patent Literature 1) Korean Patent Laid-open Publication
No. 10-2000-0051826
DETAILED DESCRIPTION OF THE INVENTION
Technical Problem
[0007] It is one object of the present invention to provide an
organic light emitting device having improved driving voltage and
efficiency.
Technical Solution
[0008] The present invention provides an organic light emitting
device comprising:
[0009] a first electrode;
[0010] a hole transport layer;
[0011] a light emitting layer;
[0012] an electron transport layer; and
[0013] a second electrode,
[0014] wherein the light emitting layer comprises a compound
represented by Chemical Formula 1 below and the electron transport
layer comprises a compound represented by Chemical Formula 2
below:
##STR00001##
[0015] in Chemical Formula 1,
[0016] Ar.sub.1 and Ar.sub.2 are the same as or different from each
other, and each independently represent a substituted or
unsubstituted C.sub.6-60 aryl,
[0017] l and p are each independently an integer of 0 to 4,
[0018] m and o are each independently an integer of 0 to 2,
[0019] R.sub.1 to R.sub.4 are the same as or different from each
other, and each independently represent hydrogen; a substituted or
unsubstituted C.sub.6-60 aryl; or C.sub.2-60 heteroaryl containing
one or more heteroatoms each independently selected from the group
consisting of N, O and S; or R.sub.1 and R.sub.2, or R.sub.3 and
R.sub.4 together form a substituted or unsubstituted C.sub.6-60
aromatic ring,
##STR00002##
[0020] in Chemical Formula 2,
[0021] X.sub.1 to X.sub.3 are the same as or different from each
other, and each independently represent N, or CH, provided that at
least one of X.sub.1 to X.sub.3 is N,
[0022] Ar.sub.4 and Ar.sub.5 are the same as or different from each
other, and each independently represent a substituted or
unsubstituted C.sub.6-60 aryl; or C.sub.2-60 heteroaryl containing
one or more heteroatoms each independently selected from the group
consisting of N, O and S;
[0023] each L is independently the same as or different from each
other, and each independently represent a substituted or
unsubstituted C.sub.6-60 arylene; or C.sub.2-60 heteroarylene
containing one or more heteroatoms each independently selected from
the group consisting of N, O, S and P, and
[0024] Ar.sub.6 is a substituted or unsubstituted C.sub.6-60
arylene; or C.sub.2-60 heteroarylene containing one or more
heteroatoms each independently selected from the group consisting
of N, O and S.
Advantageous Effects
[0025] The organic light emitting device described above is
excellent in driving voltage and efficiency.
BRIEF DESCRIPTION OF DRAWINGS
[0026] FIG. 1 shows an example of an organic light emitting device
comprising a substrate 1, an anode 2, a hole transport layer 3, a
light emitting layer 4, an electron transport layer 5, and a
cathode 6.
[0027] FIG. 2 shows an example of an organic light emitting device
comprising a substrate 1, an anode 2, a hole injection layer 7, a
hole transport layer 3, a light emitting layer 4, an electron
transport layer 5, an electron injection layer 8, and a cathode
6.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] Hereinafter, the present invention will be described in more
detail to help understanding of the present invention.
[0029] In the present specification,
##STR00003##
means a bond connected to another substituent group.
[0030] As used herein, the term "substituted or unsubstituted"
means that substitution is performed by one or more substituent
groups selected from the group consisting of deuterium; a halogen
group; a nitrile group; a nitro group; a hydroxyl group; a carbonyl
group; an ester group; an imide group; an amino group; a phosphine
oxide group; an alkoxy group; an aryloxy group; an alkylthioxy
group; an arylthioxy group; an alkylsulfoxy group; an arylsulfoxy
group; a silyl group; a boron group; an alkyl group; a cycloalkyl
group; an alkenyl group; an aryl group; an aralkyl group; an
aralkenyl group; an alkylaryl group; an alkylamine group; an
aralkylamine group; a heteroarylamine group; an arylamine group; an
arylphosphine group; or a heterocyclic group containing at least
one of N, O, and S atoms, or there is no substituent group, or
substitution is performed by a substituent group where two or more
substituent groups of the exemplified substituent groups are linked
or there is no substituent group. For example, the term
"substituent group where two or more substituent groups are linked"
may be a biphenyl group. That is, the biphenyl group may be an aryl
group, or may be interpreted as a substituent group where two
phenyl groups are linked.
[0031] In the present specification, the number of carbon atoms in
a carbonyl group is not particularly limited, but is preferably 1
to 40 carbon atoms. Specifically, the carbonyl group may be
compounds having the following structures, but is not limited
thereto.
##STR00004##
[0032] In the present specification, the ester group may have a
structure in which oxygen of the ester group may be substituted by
a straight-chain, branched-chain, or cyclic alkyl group having 1 to
25 carbon atoms, or an aryl group having 6 to 25 carbon atoms.
Specifically, the ester group may be compounds having the following
structures, but is not limited thereto.
##STR00005##
[0033] In the present specification, the number of carbon atoms in
an imide group is not particularly limited, but is preferably 1 to
25. Specifically, the imide group may be compounds having the
following structures, but is not limited thereto.
##STR00006##
[0034] In the present specification, the silyl group specifically
includes a trimethylsilyl group, a triethylsilyl group, a
t-butyldimethylsilyl group, a vinyldimethylsilyl group, a
propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl
group, a phenylsilyl group, and the like, but is not limited
thereto.
[0035] In the present specification, the boron group specifically
includes a trimethylboron group, a triethylboron group, a
t-butyldimethylboron group, a triphenylboron group, a phenylboron
group, and the like, but is not limited thereto.
[0036] In the present specification, examples of a halogen group
include fluorine, chlorine, bromine, or iodine.
[0037] In the present specification, an alkyl group may be a
straight chain or a branched chain, and the number of carbon atoms
thereof is not particularly limited, but is preferably 1 to 40.
According to one embodiment, the alkyl group has 1 to 20 carbon
atoms. According to another embodiment, the alkyl group has 1 to 10
carbon atoms. According to still another embodiment, the alkyl
group has 1 to 6 carbon atoms. Specific examples of the alkyl group
include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl,
isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl,
pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl,
n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl,
3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl,
cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl,
1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl,
2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl,
2-methylpentyl, 4-methylhexyl, 5-methylhexyl, and the like, but are
not limited thereto.
[0038] In the present specification, the alkenyl group may be a
straight chain or a branched chain, and the number of carbon atoms
thereof is not particularly limited, but is preferably 2 to 40.
According to one embodiment, the alkenyl group has 2 to 20 carbon
atoms. According to another embodiment, the alkenyl group has 2 to
10 carbon atoms. According to still another embodiment, the alkenyl
group has 2 to 6 carbon atoms. Specific examples thereof include
vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl,
1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1-butenyl,
1,3-butadienyl, allyl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl,
2,2-diphenylvinyl-1-yl, 2-phenyl-2-(naphthyl-1-yl)vinyl-1-yl,
2,2-bis(diphenyl-1-yl)vinyl-1-yl, a stilbenyl group, a styrenyl
group, and the like, but are not limited thereto.
[0039] In the present specification, a cycloalkyl group is not
particularly limited, but the number of carbon atoms thereof is
preferably 3 to 60. According to one embodiment, the cycloalkyl
group has 3 to 30 carbon atoms. According to another embodiment,
the cycloalkyl group has 3 to 20 carbon atoms. According to another
embodiment, the cycloalkyl group has 3 to 6 carbon atoms. Specific
examples thereof include cyclopropyl, cyclobutyl, cyclopentyl,
3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl,
3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl,
3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl,
cyclooctyl, and the like, but are not limited thereto.
[0040] In the present specification, the aryl group is not
particularly limited, but preferably has 6 to 60 carbon atoms, and
may be a monocyclic aryl group or a polycyclic aryl group.
According to one embodiment, the aryl group has 6 to 30 carbon
atoms. According to one embodiment, the aryl group has 6 to 20
carbon atoms. The aryl group may be a phenyl group, a biphenyl
group, a terphenyl group or the like as the monocyclic aryl group,
but is not limited thereto. Examples of the polycyclic aryl group
include a naphthyl group, an anthracenyl group, a phenanthryl
group, a pyrenyl group, a perylenyl group, a chrysenyl group, a
fluorenyl group or the like, but is not limited thereto.
[0041] In the present specification, a fluorenyl group may be
substituted, and two substituent groups may be linked with each
other to form a spiro structure. In the case where the fluorenyl
group is substituted,
##STR00007##
and the like can be formed. However, the structure is not limited
thereto.
[0042] In the present specification, the heterocyclic group is a
heterocyclic group containing at least one of O, N, Si and S as a
heteroatom, and the number of carbon atoms thereof is not
particularly limited, but is preferably 2 to 60. Examples of the
heterocyclic group include a thiophene group, a furan group, a
pyrrole group, an imidazole group, a thiazole group, an oxazole
group, an oxadiazole group, a triazole group, a pyridyl group, a
bipyridyl group, a pyrimidyl group, a triazine group, an acridyl
group, a pyridazine group, a pyrazinyl group, a quinolinyl group, a
quinazoline group, a quinoxalinyl group, a phthalazinyl group, a
pyridopyrimidinyl group, a pyridopyrazinyl group, a
pyrazinopyrazinyl group, an isoquinoline group, an indole group, a
carbazole group, a benzoxazole group, a benzimidazole group, a
benzothiazole group, a benzocarbazole group, a benzothiophene
group, a dibenzothiophene group, a benzofuranyl group, a
phenanthroline group, an isoxazolyl group, a thiadiazolyl group, a
phenothiazinyl group, a dibenzofuranyl group, and the like, but are
not limited thereto.
[0043] In the present specification, the aryl group in the aralkyl
group, the aralkenyl group, the alkylaryl group, and the arylamine
group is the same as the aforementioned examples of the aryl group.
In the present specification, the alkyl group in the aralkyl group,
the alkylaryl group and the alkylamine group is the same as the
aforementioned examples of the alkyl group. In the present
specification, the heteroaryl in the heteroarylamines can be
applied to the aforementioned description of the heterocyclic
group. In the present specification, the alkenyl group in the
aralkenyl group is the same as the aforementioned examples of the
alkenyl group. In the present specification, the aforementioned
description of the aryl group may be applied except that the
arylene is a divalent group. In the present specification, the
aforementioned description of the heterocyclic group can be applied
except that the heteroarylene is a divalent group. In the present
specification, the aforementioned description of the aryl group or
cycloalkyl group can be applied except that the hydrocarbon ring is
not a monovalent group but formed by combining two substituent
groups. In the present specification, the aforementioned
description of the heterocyclic group can be applied, except that
the heterocycle is not a monovalent group but formed by combining
two substituent groups.
[0044] The present invention provides the following organic light
emitting device:
[0045] An organic light emitting device comprising: a first
electrode; a hole transport layer; a light emitting layer; an
electron transport layer; and a second electrode, wherein the light
emitting layer includes a compound represented by Chemical Formula
1 and the electron transport layer includes a compound represented
by Chemical Formula 2.
[0046] The organic light emitting device according to the present
invention has a feature that by adjusting materials contained in
the light emitting layer and the electron transport layer and
adjusting the energy level between the respective layers, the
driving voltage can be lowered and thus the efficiency can be
improved. In particular, in the case where there is an aryl group
containing a plurality of independent heteroatoms in which a LUMO
orbital exists mainly on a linker, as in the compound represented
by Chemical Formula 2, there are advantages in that its ability to
donate electrons is improved, the electron mobility or electron
density for bulk increases, the overall conductivity increases, and
thereby the driving voltage of the device is lowered, as compared
with a compound having an aryl group containing a single
heteroatom.
[0047] Hereinafter, the present invention will be described in
detail for each configuration.
[0048] First Electrode and Second Electrode
[0049] The first electrode and second electrode used in the present
invention are electrodes used in an organic light emitting device.
For example, the first electrode is an anode and the second
electrode is a cathode, or the first electrode is a cathode and the
second electrode is an anode.
[0050] As the anode material, generally, a material having a large
work function is preferably used so that holes can be smoothly
injected into the organic material layer. Specific examples of the
anode material include metals such as vanadium, chrome, copper,
zinc, and gold, or an alloy thereof; metal oxides such as zinc
oxides, indium oxides, indium tin oxides (ITO), and indium zinc
oxides (IZO); a combination of metals and oxides, such as ZnO:Al or
SNO.sub.2:Sb; conductive polymers such as poly(3-methylthiophene),
poly[3,4-(ethylene-1,2-dioxy)thiophene](PEDOT), polypyrrole, and
polyaniline, and the like, but are not limited thereto.
[0051] As the cathode material, generally, a material having a
small work function is preferably used so that electrons can be
easily injected into the organic material layer. Specific examples
of the cathode material include metals such as magnesium, calcium,
sodium, potassium, titanium, indium, yttrium, lithium, gadolinium,
aluminum, silver, tin, and lead, or an alloy thereof; a
multilayered structure material such as LiF/Al or LiO.sub.2/Al, and
the like, but are not limited thereto.
[0052] In addition, a hole injection layer may be further included
on the anode. The hole injection layer is composed of a hole
injection material, and the hole injection material is preferably a
compound which has an ability of transporting the holes, a hole
injection effect in the anode and an excellent hole injection
effect to the light emitting layer or the light emitting material,
prevents movement of an exciton generated in the light emitting
layer to the electron injection layer or the electron injection
material, and has an excellent thin film forming ability.
[0053] It is preferable that a HOMO (highest occupied molecular
orbital) of the hole injection material is between the work
function of the anode material and a HOMO of a peripheral organic
material layer. Specific examples of the hole injection material
include metal porphyrine, oligothiophene, an arylamine-based
organic material, a hexanitrilehexaazatriphenylene-based organic
material, a quinacridone-based organic material, a perylene-based
organic material, anthraquinone, polyaniline and
polythiophene-based conductive polymer, and the like, but are not
limited thereto.
[0054] Hole Transport Layer
[0055] The hole transport layer used in the present invention is a
layer that receives holes from an anode or a hole injection layer
formed on the anode and transports the holes to the light emitting
layer.
[0056] The hole transport material is suitably a material having
large mobility to the holes, which may receive holes from the anode
or the hole injection layer and transfer the holes to the light
emitting layer. Specific examples thereof include an
arylamine-based organic material, a conductive polymer, a block
copolymer in which a conjugate portion and a non-conjugate portion
are present together, and the like, but are not limited
thereto.
[0057] Light Emitting Layer
[0058] The light emitting layer used in the present invention means
a layer that emits light in the visible light region by combining
holes and electrons respectively transported from the hole
transport layer and the electron transport layer.
[0059] In particular, the light emitting layer according to the
present invention includes a compound represented by Chemical
Formula 1. The compound represented by Chemical Formula 1 functions
as a host of the light emitting layer.
[0060] Preferably, Ar.sub.1 and Ar.sub.2 are the same as or
different from each other, and each independently represent phenyl,
biphenylyl, naphthyl, phenanthrenyl, or terphenyl.
[0061] Preferably, R.sub.1 to R.sub.4 are the same as or different
from each other, and each independently represent hydrogen, or
carbazolyl substituted with phenyl.
[0062] Preferably, the compound represented by Chemical Formula 1
is any one selected from the group consisting of:
##STR00008## ##STR00009## ##STR00010## ##STR00011##
##STR00012##
[0063] The compound represented by Chemical Formula 1 can be
prepared, by a preparation method as shown in the following
Reaction Scheme 1. The preparation method can be further specified
in Preparation Examples to be described later.
[0064] [Reaction Scheme 1]
##STR00013##
[0065] in Reaction Scheme 1, Ar.sub.1, Ar.sub.2, l, p, m, o, and
R.sub.1 to R.sub.4 are as defined above, and X is halogen (I, Br,
or Cl). The reaction is a step of coupling a compound substituted
with halogen and an aromatic compound substituted with boronic acid
derivative using a palladium catalyzed reaction to prepare a
compound represented by Chemical Formula 1. The preparation method
can be further specified in Preparation Examples to be described
later.
[0066] The light emitting layer includes a dopant in addition to
the compound represented by Chemical Formula 1. The dopant includes
an aromatic amine derivative, a styrylamine compound, a boron
complex, a fluoranthene compound, a metal complex, and the like.
Specifically, the aromatic amine derivative is a condensed aromatic
cycle derivative having a substituted or unsubstituted arylamino
group, examples thereof include pyrene, anthracene, chrysene, and
periflanthene having the arylamino group, and the like, the
styrylamine compound is a compound where at least one arylvinyl
group is substituted in substituted or unsubstituted arylamine, in
which one or two or more substituent groups selected from the group
consisting of an aryl group, a silyl group, an alkyl group, a
cycloalkyl group, and an arylamino group are substituted or
unsubstituted. Specific examples thereof include styrylamine,
styryldiamine, styryltriamine, styryltetramine, and the like, but
are not limited thereto. Further, examples of the metal complex
include an iridium complex, a platinum complex, and the like, but
are not limited thereto.
[0067] Electron Transport Layer
[0068] The electron transport layer used in the present invention
is a layer that receives electrons from a cathode or an electron
injection layer formed on the cathode and transports the electrons
to the light emitting layer.
[0069] In particular, the electron transport layer according to the
present invention includes a compound represented by Chemical
Formula 2.
[0070] Preferably, X.sub.1 to X.sub.3 are N.
[0071] Preferably, Ar.sub.4 and Ar.sub.5 are the same as or
different from each other, and each independently represent phenyl,
phenyl substituted with methyl, or naphthyl.
[0072] Preferably, L is phenylene.
[0073] Preferably, Ar.sub.6 is phenylene, naphthylene,
phenanthrenylene, dimethylfluorenylene, dibenzofuranylene, or
dibenzothiophenylene.
[0074] Preferably, the compound represented by Chemical Formula 2
is any one selected from the group consisting of:
##STR00014## ##STR00015## ##STR00016## ##STR00017## ##STR00018##
##STR00019## ##STR00020##
[0075] The compound represented by Chemical Formula 2 can be
prepared, by a preparation method as shown in the following
Reaction Scheme 2.
##STR00021##
[0076] in Reaction Scheme 2, X.sub.1 to X.sub.3, Ar.sub.4,
Ar.sub.5, L, and Ar.sub.6 are as defined above, and X is halogen
(I, Br, or Cl). The reaction is a step of coupling a compound
substituted with halogen and an aromatic compound substituted with
boronic acid derivative using a palladium catalyzed reaction to
prepare a compound represented by Chemical Formula 2. The
preparation method can be further specified in Preparation Examples
to be described later.
[0077] Electron Injection Layer
[0078] The organic light emitting device according to the present
invention may further include an electron injection layer between
the electron transport layer and the cathode. The electron
injection layer is a layer injecting electrons from the electrode,
and a compound which has an ability of transporting the electrons,
an electron injection effect from the cathode, and an excellent
electron injection effect to the light emitting layer or the light
emitting material, prevents movement of an exciton generated in the
light emitting layer to the hole injection layer, and has an
excellent thin film forming ability is preferable.
[0079] Specific examples materials that can be used for the
electron injection layer include fluorenone, anthraquinodimethane,
diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole,
imidazole, perylene tetracarboxylic acid, fluorenylidene methane,
anthrone, and the like, and its derivative, a metal complex
compound, a nitrogen-containing 5-membered cycle derivative, and
the like, but are not limited thereto.
[0080] Examples of the metal complex compound include
8-hydroxyquinolinato lithium, bis(8-hydroxyquinolinato)zinc,
bis(8-hydroxyquinolinato)copper,
bis(8-hydroxyquinolinato)manganese,
tris(8-hydroxyquinolinato)aluminum,
tris(2-methyl-8-hydroxyquinolinato)aluminum,
tris(8-hydroxyquinolinato)gallium,
bis(10-hydroxybenzo[h]quinolinato)beryllium,
bis(10-hydroxybenzo[h]quinolinato)zinc,
bis(2-methyl-8-quinolinato)chlorogallium,
bis(2-methyl-8-quinolinato)(o-cresolato)gallium,
bis(2-methyl-8-quinolinato)(1-naphtholato)aluminum,
bis(2-methyl-8-quinolinato)(2-naphtholato)gallium, and the like,
but are not limited thereto.
[0081] Organic Light Emitting Device
[0082] The structure of the organic light emitting device according
to the present invention is illustrated in FIG. 1. FIG. 1 shows an
example of an organic light emitting device comprising a substrate
1, an anode 2, a hole transport layer 3, a light emitting layer 4,
an electron transport layer 5, and a cathode 6.
[0083] Further, another structure of the organic light emitting
device according to the present invention is illustrated in FIG. 2.
FIG. 2 shows an example of an organic light emitting device
comprising a substrate 1, an anode 2, a hole injection layer 7, a
hole transport layer 3, a light emitting layer 4, an electron
transport layer 5, an electron injection layer 8 and a cathode
6.
[0084] The organic light emitting device according to the present
invention may be manufactured by sequentially laminating the
above-described structures. In this case, the organic light
emitting device may be manufactured by depositing a metal, metal
oxides having conductivity, or an alloy thereof on the substrate by
using a PVD (physical vapor deposition) method such as a sputtering
method or an e-beam evaporation method to form the anode, forming
the organic material layer including the hole injection layer, the
hole transport layer, the light emitting layer, and the electron
transport layer thereon, and then depositing a material that can be
used as the cathode thereon. In addition to such a method, the
organic light emitting device may be manufactured by sequentially
depositing a cathode material, an organic material layer and an
anode material on a substrate. In addition, the light emitting
layer may be formed by subjecting a host and a dopant to a vacuum
evaporation as well as a solution coating. Herein, the solution
coating method means spin coating, dip coating, doctor blading,
inkjet printing, screen printing, spray method, roll coating, or
the like, but is not limited thereto.
[0085] In addition to such a method, the organic light emitting
device may be manufactured by sequentially depositing a cathode
material, an organic material layer, and an anode material on a
substrate (International Publication WO 2003/012890). However, the
manufacturing method is not limited thereto.
[0086] Meanwhile, the organic light emitting device according to
the present invention may be a front side emission type, a back
side emission type, or a double side emission type according to the
used material.
[0087] Hereinafter, preferred examples of the present invention
will be described in order to facilitate understanding of the
present invention. However, the following examples are presented
for illustrative purposes only, and the scope of the present
invention is not limited thereto.
Preparation Example 1
Preparation Example 1-1
##STR00022##
[0089] The compound (20 g, 69.7 mmol) represented by Chemical
Formula 1-A and the compound (27.8 g, 69.7 mmol) represented by
Chemical Formula 1-B were added to 300 mL of THF under nitrogen
atmosphere, 150 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(1.6 g, 1.4 mmol) was added thereto, and then the mixture was
heated and stirred for 6 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (30.1 g, yield 77%)
represented by Chemical Formula 1-1.
[0090] MS: [M+H].sup.+=561
Preparation Example 1-2
##STR00023##
[0092] The compound (10 g, 30.2 mmol) represented by Chemical
Formula 1-C and the compound (19.5 g, 60.4 mmol) represented by
Chemical Formula 1-D were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(0.7 g, 0.6 mmol) was added thereto, and then the mixture was
heated and stirred for 7 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (14.5 g, yield 66%)
represented by Chemical Formula 1-2.
[0093] MS: [M+H].sup.+=726
Preparation Example 1-3
##STR00024##
[0095] The compound (15 g, 44.5 mmol) represented by Chemical
Formula 1-E and the compound (14.3 g, 44.5 mmol) represented by
Chemical Formula 1-0 were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(1.03 g, 0.9 mmol) was added thereto, and then the mixture was
heated and stirred for 10 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (17.9 g, yield 75%)
represented by Chemical Formula 1-3.
[0096] MS: [M+H].sup.+=535
Preparation Example 1-4
##STR00025##
[0098] The compound (15 g, 41.3 mmol) represented by Chemical
Formula 1-F and the compound (16.4 g, 41.3 mmol) represented by
Chemical Formula 1-G were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(0.95 g, 0.8 mmol) was added thereto, and then the mixture was
heated and stirred for 8 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (17.9 g, yield 68%)
represented by Chemical Formula 1-4.
[0099] MS: [M+H].sup.+=637
Preparation Example 2
Preparation Example 2-1
##STR00026##
[0101] The compound (20 g, 51.5 mmol) represented by Chemical
Formula 2-A and the compound (11.1 g, 25.8 mmol) represented by
Chemical Formula 2-B were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(1.2 g, 1.0 mmol) was added thereto, and then the mixture was
heated and stirred for 6 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (15.5 g, yield 76%)
represented by Chemical Formula 2-1.
[0102] MS: [M+H].sup.+=793
Preparation Example 2-2
##STR00027##
[0104] The compound (20 g, 51.5 mmol) represented by Chemical
Formula 2-C and the compound (11.1 g, 25.8 mmol) represented by
Chemical Formula 2-B were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(1.2 g, 1.0 mmol) was added thereto, and then the mixture was
heated and stirred for 8 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (17.1 g, yield 84%)
represented by Chemical Formula 2-2.
[0105] MS: [M+H].sup.+=793
Preparation Example 2-3
##STR00028##
[0107] The compound (20 g, 51.5 mmol) represented by Chemical
Formula 2-C and the compound (9.8 g, 25.8 mmol) represented by
Chemical Formula 2-D were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(1.2 g, 1.0 mmol) was added thereto, and then the mixture was
heated and stirred for 10 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (17.1 g, yield 84%)
represented by Chemical Formula 2-3.
[0108] MS: [M+H].sup.+=743
Preparation Example 2-4
##STR00029##
[0110] The compound (20 g, 51.5 mmol) represented by Chemical
Formula 2-A and the compound (9.8 g, 25.8 mmol) represented by
Chemical Formula 2-E were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(1.2 g, 1.0 mmol) was added thereto, and then the mixture was
heated and stirred for 7 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (13.2 g, yield 69%)
represented by Chemical Formula 2-4.
[0111] MS: [M+H].sup.+=743
Preparation Example 2-5
##STR00030##
[0113] The compound (20 g, 51.5 mmol) represented by Chemical
Formula 2-C and the compound (9.8 g, 25.8 mmol) represented by
Chemical Formula 2-F were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(1.2 g, 1.0 mmol) was added thereto, and then the mixture was
heated and stirred for 9 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (14.7 g, yield 77%)
represented by Chemical Formula 2-5.
[0114] MS: [M+H].sup.+=743
Preparation Example 2-6
##STR00031##
[0116] The compound (20 g, 51.5 mmol) represented by Chemical
Formula 2-C and the compound (10.8 g, 25.8 mmol) represented by
Chemical Formula 2-G were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(1.2 g, 1.0 mmol) was added thereto, and then the mixture was
heated and stirred for 12 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (13.3 g, yield 66%)
represented by Chemical Formula 2-6.
[0117] MS: [M+H].sup.+=783
Preparation Example 2-7
##STR00032##
[0119] The compound (20 g, 45.8 mmol) represented by Chemical
Formula 2-H and the compound (7.6 g, 22.9 mmol) represented by
Chemical Formula 2-1 were added to 200 mL of THF under nitrogen
atmosphere, 100 mL of 2M potassium carbonate aqueous solution was
added while stirring, and tetrakis triphenylphosphine palladium
(1.2 g, 1.0 mmol) was added thereto, and then the mixture was
heated and stirred for 8 hours. After lowering the temperature to
room temperature, the reaction was terminated, the potassium
carbonate aqueous solution was removed, and a white solid formed
during the reaction was filtered. The filtered solid was
recrystallized from THF to prepare the compound (13.6 g, yield 75%)
represented by Chemical Formula 2-7.
[0120] MS: [M+H].sup.+=793
[0121] In addition to the above compounds, the compounds used in
the following Examples and Comparative Examples were as
follows.
##STR00033## ##STR00034## ##STR00035##
Example and Comparative Example
[0122] A glass substrate on which a thin film of ITO (indium tin
oxide) was coated in a thickness of 150 mm was added to distilled
water containing the detergent dissolved therein and washed by the
ultrasonic wave. The used detergent was a product commercially
available from Fisher Co. and the distilled water was one which had
been twice filtered by using a filter commercially available from
Millipore Co. The ITO was washed for 30 minutes, and ultrasonic
washing was then repeated twice for 10 minutes by using distilled
water. After the washing with distilled water was completed, the
substrate was ultrasonically washed with isopropyl alcohol,
acetone, and methanol solvent, and dried, after which it was
transported to a plasma cleaner. In addition, the substrate was
cleaned with oxygen plasma for 5 minutes, and then transferred to a
vacuum evaporator. On the ITO transparent electrode thus prepared,
a compound HI-1 described below was thermally vacuum-deposited in a
thickness of 50 .ANG. to form a hole injection layer. A compound
HTL was then thermally vacuum-deposited on the hole injection layer
in a thickness of 200 .ANG. to form a hole transport layer. Then,
the compound of Preparation Example 1-1 previously prepared as a
host and a GD compound as a dopant (weight ratio of 9:1) were
simultaneously vacuum-deposited to form a light emitting layer
having a thickness of 400 .ANG.. Then, the compound of Preparation
Example 2-1 previously prepared was vacuum-deposited in a thickness
of 350 .ANG. to form an electron transport layer. Then, LiG was
vacuum-deposited in a thickness of 10 .ANG. to form an electron
injection layer, and aluminum (1000 .ANG.) was vapor-deposited to
form a cathode, thereby preparing an organic light emitting
device.
[0123] An organic light emitting device was prepared in the same
manner as described above, except that a material as shown in Table
1 below was used and a light emitting layer and an electron
transport layer were used.
[0124] An electric current was applied to the prepared organic
light emitting device to measure the driving voltage, efficiency,
and color coordinate, and the results are shown in Table 1
below.
TABLE-US-00001 TABLE 1 Material applied Electron @ 10 mA/cm.sup.2
Host transport layer V Cd/A CIE_x CIE_y Example 1 1-1 2-1 4.0 57.3
0.354 0.353 Example 2 1-2 2-2 3.5 58.1 0.333 0.332 Example 3 1-3
2-3 3.5 56.7 0.338 0.337 Example 4 1-9 2-4 3.4 55.4 0.338 0.337
Example 5 1-1 2-5 4.2 55.7 0.342 0.341 Example 6 1-2 2-6 3.1 58.9
0.353 0.352 Example 7 1-3 2-7 4.3 56.0 0.330 0.329 Example 8 1-9
2-1 3.2 57.3 0.333 0.332 Example 9 1-1 2-2 3.8 58.4 0.335 0.334
Example 10 1-2 2-4 3.9 55.0 0.337 0.336 Example 11 1-3 2-6 4.0 56.4
0.353 0.353 Example 12 1-9 2-7 3.6 58.5 0.328 0.327 Comparative
Host 1 ETL1 6.0 33.6 0.323 0.322 Example 1 Comparative Host 2 ETL2
6.5 43.7 0.327 0.326 Example 2 Comparative 1-1 ETL1 6.6 44.4 0.329
0.328 Example 3 Comparative 1-2 ETL2 6.6 45.5 0.330 0.330 Example 4
Comparative 1-3 ETL1 5.8 50.0 0.350 0.349 Example 5 Comparative
Host 1 2-1 5.6 47.0 0.324 0.323 Example 6 Comparative Host 2 2-2
6.1 44.6 0.333 0.332 Example 7 Comparative Host 1 2-4 5.6 44.6
0.335 0.334 Example 8 Comparative Host 2 2-7 5.8 37.3 0.338 0.337
Example 9 Comparative Host 3 ETL3 5.6 40.0 0.329 0.330 Example
10
[0125] As shown in Table 1, it was confirmed that the driving
voltage of the organic light emitting device according to the
present invention was significantly lower than that of Comparative
Examples.
TABLE-US-00002 [Explanation of Sign] 1: substrate 2: anode, 3: hole
transport layer 4: light emitting layer 5: electron transport layer
6: cathode 7: hole injection layer 8: electron injection layer
* * * * *