U.S. patent application number 14/854317 was filed with the patent office on 2016-01-14 for deuterated compounds for luminescent applications.
The applicant listed for this patent is E I DU PONT DE NEMOURS AND COMPANY. Invention is credited to KALINDI DOGRA, ADAM FENNIMORE, WEIYING GAO, NORMAN HERRON, MICHAEL HENRY HOWARD, JR., DANIEL DAVID LECLOUX, JEFFREY A. MERLO, NORA SABINA RADU, VSEVOLOD ROSTOVTSEV, ERIC MAURICE SMITH, WEISHI WU.
Application Number | 20160013413 14/854317 |
Document ID | / |
Family ID | 42353617 |
Filed Date | 2016-01-14 |
United States Patent
Application |
20160013413 |
Kind Code |
A1 |
HERRON; NORMAN ; et
al. |
January 14, 2016 |
DEUTERATED COMPOUNDS FOR LUMINESCENT APPLICATIONS
Abstract
This invention relates to deuterated compounds that are useful
in electroluminescent applications. It also relates to electronic
devices in which the active layer includes such a deuterated
compound.
Inventors: |
HERRON; NORMAN; (NEWARK,
DE) ; ROSTOVTSEV; VSEVOLOD; (SWARTHMORE, PA) ;
MERLO; JEFFREY A.; (WILMINGTON, DE) ; HOWARD, JR.;
MICHAEL HENRY; (MONTCHANIN, DE) ; FENNIMORE;
ADAM; (WILMINGTON, DE) ; GAO; WEIYING;
(LANDENBERG, PA) ; DOGRA; KALINDI; (WILMINGTON,
DE) ; RADU; NORA SABINA; (LANDENBERG, PA) ;
WU; WEISHI; (LANDENBERG, PA) ; SMITH; ERIC
MAURICE; (HOCKESSIN, DE) ; LECLOUX; DANIEL DAVID;
(MIDLAND, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
E I DU PONT DE NEMOURS AND COMPANY |
Wilmington |
DE |
US |
|
|
Family ID: |
42353617 |
Appl. No.: |
14/854317 |
Filed: |
September 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13945381 |
Jul 18, 2013 |
9166174 |
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14854317 |
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12643511 |
Dec 21, 2009 |
8531100 |
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13945381 |
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61139834 |
Dec 22, 2008 |
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61176141 |
May 7, 2009 |
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Current U.S.
Class: |
257/40 |
Current CPC
Class: |
H01L 51/0054 20130101;
H01L 51/006 20130101; C07B 59/001 20130101; C09K 2211/1014
20130101; H05B 33/14 20130101; C07C 2603/24 20170501; H01L 51/5088
20130101; H01L 51/5012 20130101; C07C 211/61 20130101; C09K 11/06
20130101; H01L 51/0058 20130101; C07C 2603/48 20170501 |
International
Class: |
H01L 51/00 20060101
H01L051/00 |
Claims
1.-16. (canceled)
17. An organic electronic device comprising a first electrical
contact layer, a second electrical contact layer, and at least one
active layer therebetween, wherein the active layer comprises a
compound selected from the group consisting of
diarylaminochrysenes, said compound having at least one D.
18. The device of claim 17, wherein the compound has Formula II:
##STR00015## wherein: R.sup.1 is the same or different at each
occurrence and is selected from the group consisting of D, alkyl,
alkoxy and aryl, where adjacent R.sup.1 groups may be joined
together to form a 5- or 6-membered aliphatic ring; Ar.sup.1
through Ar.sup.4 are the same or different and are selected from
the group consisting of aryl groups; and b is the same or different
at each occurrence and is an integer from 0 to 5; wherein the
compound has at least one D.
19. The device of claim 18, wherein R.sup.1 is a deuterated
alkyl.
20. (canceled)
21. The device of claim 18 having Formula II, wherein b=5 and
R.sup.1 is D.
22. The device of claim 18, wherein Ar.sup.1 through Ar.sup.4 is
selected from the group consisting of naphthyl, phenylnapthyl,
naphthylphenyl, binaphthyl, and a compound having Formula III:
##STR00016## where: R.sup.2 is the same or different at each
occurrence and is selected from the group consisting of D, alkyl,
alkoxy, aryl, silyl, and siloxane, or adjacent R.sup.2 groups can
be joined to form an aromatic ring; c is the same or different at
each occurrence and is an integer from 0-4; d is the same or
different at each occurrence and is an integer from 0-5; and m is
the same or different at each occurrence and is an integer from 0
to 6.
23. The device of claim 18, wherein the compound is selected from
E3 through E9.
24. The device of claim 18, wherein the active layer is an
electroactive layer and further comprises a host material.
25. The device of claim 24, further comprising a buffer layer
between the first electrical contact layer and the active
layer.
26. The device of claim 25, wherein the buffer layer comprises at
least one electrically conductive polymer and at least one
fluorinated acid polymer.
27. The device of claim 17, wherein the compound has at least 50%
deuteration.
28. The device of claim 18, wherein the compound has at least one
substituent group on an aryl ring, wherein deuteration is on the
substituent group on the aryl ring.
29. The device of claim 18, wherein at least one of Ar.sup.1
through Ar.sup.4 is a deuterated aryl group.
30. The device of claim 29, wherein Ar.sup.1 through Ar.sup.4 are
at least 20% deuterated.
31. The device of claim 18 wherein the compound has at least one
substituent on an aryl ring, wherein deuteration is present on both
at least one substituent group and at least one aryl ring.
32. The device of claim 18, wherein R.sup.1 is a hydrocarbon
alkyl.
33. The device of claim 18, wherein b=0.
34. The device of claim 18, wherein b=5 and R.sup.1 is D.
35. The device of claim 18, wherein Ar.sup.1 through Ar.sup.4 are
perdeuterated.
Description
RELATED APPLICATION DATA
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) from U.S. Provisional Application No. 61/139,834 filed
on Dec. 22, 2008, U.S. Provisional Application No. 61/176,141 filed
on May 7, 2009, each of which is incorporated by reference herein
in its entirety.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] This invention relates to electroactive compounds which are
at least partially deuterated. It also relates to electronic
devices in which at least one active layer includes such a
compound.
[0004] 2. Description of the Related Art
[0005] Organic electronic devices that emit light, such as
light-emitting diodes that make up displays, are present in many
different kinds of electronic equipment. In all such devices, an
organic active layer is sandwiched between two electrical contact
layers. At least one of the electrical contact layers is
light-transmitting so that light can pass through the electrical
contact layer. The organic active layer emits light through the
light-transmitting electrical contact layer upon application of
electricity across the electrical contact layers.
[0006] It is well known to use organic electroluminescent compounds
as the active component in light-emitting diodes. Simple organic
molecules such as anthracene, thiadiazole derivatives, and coumarin
derivatives are known to show electroluminescence. Semiconductive
conjugated polymers have also been used as electroluminescent
components, as has been disclosed in, for example, U.S. Pat. No.
5,247,190, U.S. Pat. No. 5,408,109, and Published European Patent
Application 443 861.
[0007] However, there is a continuing need for electroluminescent
compounds.
SUMMARY
[0008] There is provided a compound selected from the group
consisting of a bis(diarylamino)anthracene and a
bis(diarylamino)chrysene, wherein the compound has at least one
D.
[0009] There is also provided an electronic device comprising an
active layer comprising the above compound.
[0010] There is also provided a compound having Formula I or
Formula II:
##STR00001##
wherein: [0011] R.sup.1 is the same or different at each occurrence
and is selected from the group consisting of D, alkyl, alkoxy and
aryl, where adjacent R.sup.1 groups may be joined together to form
a 5- or 6-membered aliphatic ring; [0012] Ar.sup.1 0 through
Ar.sup.4 are the same or different and are selected from the group
consisting of aryl groups; [0013] a is the same or different at
each occurrence and is an integer from 0 to 4; and [0014] b is the
same or different at each occurrence and is an integer from 0 to 5;
[0015] wherein there is at least one D.
[0016] There is also provided an electronic device comprising an
active layer comprising a compound of Formula I or Formula II.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Embodiments are illustrated in the accompanying figures to
improve understanding of concepts as presented herein.
[0018] FIG. 1 includes an illustration of one example of an organic
electronic device.
[0019] Skilled artisans appreciate that objects in the figures are
illustrated for simplicity and clarity and have not necessarily
been drawn to scale. For example, the dimensions of some of the
objects in the figures may be exaggerated relative to other objects
to help to improve understanding of embodiments.
DETAILED DESCRIPTION
[0020] Many aspects and embodiments are disclosed herein and are
exemplary and not limiting. After reading this specification,
skilled artisans appreciate that other aspects and embodiments are
possible without departing from the scope of the invention.
[0021] Other features and benefits of any one or more of the
embodiments will be apparent from the following detailed
description, and from the claims. The detailed description first
addresses Definitions and Clarification of Terms followed by the
Electroactive Compound, the Electronic Device, and finally
Examples.
1. Definitions and Clarification of Terms
[0022] Before addressing details of embodiments described below,
some terms are defined or clarified.
[0023] As used herein, the term "aliphatic ring" is intended to
mean a cyclic group that does not have delocalized pi electrons. In
some embodiments, the aliphatic ring has no unsaturation. In some
embodiments, the ring has one double or triple bond.
[0024] The term "alkoxy" refers to the group RO--, where R is an
alkyl.
[0025] The term "alkyl" is intended to mean a group derived from an
aliphatic hydrocarbon having one point of attachment, and includes
a linear, a branched, or a cyclic group. The term is intended to
include heteroalkyls and deuterated alkyls. The term is intended to
include substituted and unsubstituted groups. The term "hydrocarbon
alkyl" refers to an alkyl group having no heteroatoms. The term
"deuterated alkyl" is a hydrocarbon alkyl having at least one
available H replaced by D. In some embodiments, an alkyl group has
from 1-20 carbon atoms.
[0026] The term "aryl" is intended to mean a group derived from an
aromatic hydrocarbon having one point of attachment. The term
"aromatic compound" is intended to mean an organic compound
comprising at least one unsaturated cyclic group having delocalized
pi electrons. The term is intended to include heteroaryls and
deuterated aryls. The term "hydrocarbon aryl" is intended to mean
aromatic compounds having no heteroatoms in the ring. The term aryl
includes groups which have a single ring and those which have
multiple rings which can be joined by a single bond or fused
together. The term "deuterated aryl" refers to an aryl group having
at least one of the available H atoms which is bonded directly to
the aryl replaced by D. The term "arylene" is intended to mean a
group derived from an aromatic hydrocarbon having two points of
attachment. Any suitable ring position of the aryl moiety may be
covalently linked to the defined chemical structure. In some
embodiments, a hydrocarbon aryl group has from 3-60 carbon atoms;
in some embodiments, 6 to 30 carbon atoms. Heteroaryl groups may
have from 3-50 carbon atoms; in some embodiments, 3-30 carbon
atoms.
[0027] The term "branched alkyl" refers to an alkyl group having at
least one secondary or tertiary carbon. The term "secondary alkyl"
refers to a branched alkyl group having a secondary carbon atom.
The term "tertiary alkyl" refers to a branched alkyl group having a
tertiary carbon atom. In some embodiments, the branched alkyl group
is attached via a secondary or tertiary carbon.
[0028] The term "charge transport," when referring to a layer,
material, member, or structure is intended to mean such layer,
material, member, or structure facilitates migration of such charge
through the thickness of such layer, material, member, or structure
with relative efficiency and small loss of charge. Hole transport
materials facilitate positive charge; electron transport material
facilitate negative charge. Although light-emitting materials may
also have some charge transport properties, the terms "charge,
hole, or electron transport layer, material, member, or structure"
are not intended to include a layer, material, member, or structure
whose primary function is light emission.
[0029] The term "compound" is intended to mean an electrically
uncharged substance made up of molecules that further consist of
atoms, wherein the atoms cannot be separated by physical means. The
phrase "adjacent to," when used to refer to layers in a device,
does not necessarily mean that one layer is immediately next to
another layer. On the other hand, the phrase "adjacent R groups,"
is used to refer to R groups that are next to each other in a
chemical formula (i.e., R groups that are on atoms joined by a
bond).
[0030] The term "deuterated" is intended to mean that at least one
available H has been replaced by D. A compound or group that is X%
deuterated, has X% of the available H replaced by D. A compound or
group which is deuterated is one in which deuterium is present in
at least 100 times the natural abundance level.
[0031] The term "electroactive" as it refers to a layer or a
material, is intended to indicate a layer or material which
electronically facilitates the operation of the device. Examples of
active materials include, but are not limited to, materials which
conduct, inject, transport, or block a charge, where the charge can
be either an electron or a hole, or materials which emit radiation
or exhibit a change in concentration of electron-hole pairs when
receiving radiation. Examples of inactive materials include, but
are not limited to, planarization materials, insulating materials,
and environmental barrier materials.
[0032] The prefix "hetero" indicates that one or more carbon atoms
have been replaced with a different atom. In some embodiments, the
different atom is N, O, or S.
[0033] The term "layer" is used interchangeably with the term
"film" and refers to a coating covering a desired area. The term is
not limited by size. The area can be as large as an entire device
or as small as a specific functional area such as the actual visual
display, or as small as a single sub-pixel. Layers and films can be
formed by any conventional deposition technique, including vapor
deposition, liquid deposition (continuous and discontinuous
techniques), and thermal transfer. Continuous deposition
techniques, include but are not limited to, spin coating, gravure
coating, curtain coating, dip coating, slot-die coating, spray
coating, and continuous nozzle coating. Discontinuous deposition
techniques include, but are not limited to, ink jet printing,
gravure printing, and screen printing.
[0034] The term "organic electronic device" or sometimes just
"electronic device" is intended to mean a device including one or
more organic semiconductor layers or materials.
[0035] The term "oxyalkyl" is intended to mean a heteroalkyl group
having one or more carbons replaced with oxygens. The term includes
groups which are linked via an oxygen.
[0036] The term "silyl" refers to the group R.sub.3Si--, where R is
H, D, C1-20 alkyl, fluoroalkyl, or aryl. In some embodiments, one
or more carbons in an R alkyl group are replaced with Si. In some
embodiments, the silyl groups are
(hexyl).sub.2Si(Me)CH.sub.2CH.sub.2Si(Me).sub.2-- and
[CF.sub.3(CF.sub.2).sub.6CH.sub.2CH.sub.2].sub.2SiMe--.
[0037] The term "siloxane" refers to the group (RO).sub.3Si--,
where R is H, D, C1-20 alkyl, or fluoroalkyl.
[0038] All groups can be substituted or unsubstituted unless
otherwise indicated. In some embodiments, the substituents are
selected from the group consisting of D, halide, alkyl, alkoxy,
aryl, and cyano. An optionally substituted group, such as, but not
limited to, alkyl or aryl, may be substituted with one or more
substituents which may be the same or different. Other suitable
substituents include nitro, cyano, --N(R')(R''), hydroxy, carboxy,
alkenyl, alkynyl, aryloxy, alkoxycarbonyl, perfluoroalkyl,
perfluoroalkoxy, arylalkyl, silyl, siloxane, thioalkoxy,
--S(O).sub.2--N(R')(R''), --C(.dbd.O)--N(R)(R''), (R')(R'')N-alkyl,
(R')(R'')N-alkoxyalkyl, (R')(R'')N-alkylaryloxyalkyl,
--S(O).sub.s-aryl (where s=0-2) or --S(O).sub.s-heteroaryl (where
s=0-2). Each R' and R'' is independently an optionally substituted
alkyl, cycloalkyl, or aryl group. R' and R'', together with the
nitrogen atom to which they are bound, can form a ring system in
certain embodiments. Substituents may also be crosslinking groups.
As used herein, the terms "comprises," "comprising," "includes,"
"including," "has," "having" or any other variation thereof, are
intended to cover a non-exclusive inclusion. For example, a
process, method, article, or apparatus that comprises a list of
elements is not necessarily limited to only those elements but may
include other elements not expressly listed or inherent to such
process, method, article, or apparatus. Further, unless expressly
stated to the contrary, "or" refers to an inclusive or and not to
an exclusive or. For example, a condition A or B is satisfied by
any one of the following: A is true (or present) and B is false (or
not present), A is false (or not present) and B is true (or
present), and both A and B are true (or present).
[0039] Also, use of "a" or "an" are employed to describe elements
and components described herein. This is done merely for
convenience and to give a general sense of the scope of the
invention. This description should be read to include one or at
least one and the singular also includes the plural unless it is
obvious that it is meant otherwise.
[0040] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
methods and materials similar or equivalent to those described
herein can be used in the practice or testing of the present
invention, suitable methods and materials are described below. All
publications, patent applications, patents, and other references
mentioned herein are incorporated by reference in their entirety.
In case of conflict, the present specification, including
definitions, will control. In addition, the materials, methods, and
examples are illustrative only and not intended to be limiting.
[0041] The IUPAC numbering system is used throughout, where the
groups from the Periodic Table are numbered from left to right as
1-18 (CRC Handbook of Chemistry and Physics, 81st Edition,
2000).
2. Electroactive Compound
[0042] The compound described herein is a
bis(diarylamino)anthracene or a bis(diarylamino)chrysene having at
least one D. In some embodiments, the compound is at least 10%
deuterated; in some embodiments, at least 20% deuterated; in some
embodiments, at least 30% deuterated; in some embodiments, at least
40% deuterated; in some embodiments, at least 50% deuterated; in
some embodiments, at least 60% deuterated; in some embodiments, at
least 70% deuterated; in some embodiments, at least 80% deuterated;
in some embodiments, at least 90% deuterated.
[0043] In some embodiments, the electroactive compound has Formula
I or Formula II:
##STR00002##
wherein: [0044] R.sup.1 is the same or different at each occurrence
and is selected from the group consisting of D, alkyl, alkoxy and
aryl, where adjacent R.sup.1 groups may be joined together to form
a 5- or 6-membered aliphatic ring; [0045] Ar.sup.1 through Ar.sup.4
are the same or different and are selected from the group
consisting of aryl groups; [0046] a is the same or different at
each occurrence and is an integer from 0 to 4; and [0047] b is the
same or different at each occurrence and is an integer from 0 to 5;
[0048] wherein the compound has at least one D. In some
embodiments, the compounds are capable of red, green or blue
emission.
[0049] In some embodiments of Formulae I and II, the deuteration is
on a substituent group on an aryl ring. The aryl group having a
deuterated substituent group can be can be the core anthracene
group of Formula I or the core chrysene group of Formula II; or an
aryl on the nitrogen; or a substituent aryl group. In some
embodiments, the deuterated substituent group on an aryl ring is
selected from alkyl, aryl, alkoxy, and aryloxy. In some
embodiments, the substituent groups are at least 10% deuterated; in
some embodiments, at least 20% deuterated; in some embodiments, at
least 30% deuterated; in some embodiments, at least 40% deuterated;
in some embodiments, at least 50% deuterated; in some embodiments,
at least 60% deuterated; in some embodiments, at least 70%
deuterated; in some embodiments, at least 80% deuterated; in some
embodiments, at least 90% deuterated.
[0050] In some embodiments of Formulae I and II, the deuteration is
on any one or more of the aryl groups Ar.sup.1 through Ar.sup.4. In
this case, at least one of Ar.sup.1 through Ar.sup.4 is a
deuterated aryl group. In some embodiments, Ar.sup.1 through
Ar.sup.4 are at least 10% deuterated. By this it is meant that at
least 10% of all the available H bonded to aryl C in Ar.sup.1
through Ar.sup.4 are replaced with D. In some embodiments, each
aryl ring will have some D. In some embodiments, some, and not all
of the aryl rings have D. In some embodiments, Ar.sup.1 through
Ar.sup.4 are at least 20% deuterated; in some embodiments, at least
30% deuterated; in some embodiments, at least 40% deuterated; in
some embodiments, at least 50% deuterated; in some embodiments, at
least 60% deuterated; in some embodiments, at least 70% deuterated;
in some embodiments, at least 80% deuterated; in some embodiments,
at least 90% deuterated.
[0051] In some embodiments of Formulae I and II, the deuteration is
present on both the substituent groups and the aryl groups.
In some embodiments, the compound of Formulae I and II is at least
10% deuterated; in some embodiments, at least 20% deuterated; in
some embodiments, at least 30% deuterated; in some embodiments, at
least 40% deuterated; in some embodiments, at least 50% deuterated;
in some embodiments, at least 60% deuterated; in some embodiments,
at least 70% deuterated; in some embodiments, at least 80%
deuterated; in some embodiments, at least 90% deuterated.
[0052] In some embodiments of Formula I, both a=0.
[0053] In some embodiments of Formula I, at least one a is greater
than 0. In some embodiments, at least one R.sup.1 is a hydrocarbon
alkyl. In some embodiments, R.sup.1 is a deuterated alkyl. In some
embodiments, R.sup.1 is selected from a branched hydrocarbon alkyl
and a cyclic hydrocarbon alkyl.
[0054] In some embodiments of Formula I, both a=4 and R.sup.1 is
D.
[0055] In Formula II, the bond to (R.sup.1), is intended to
indicate that the R.sup.1 group can be at any site on the two fused
rings.
[0056] In some embodiments of Formula II, both b=0.
[0057] In some embodiments of Formula II, at least one b is greater
than 0. In some embodiments, at least one R.sup.1 is a hydrocarbon
alkyl. In some embodiments, R.sup.1 is selected from a branched
hydrocarbon alkyl and a cyclic hydrocarbon alkyl.
[0058] In some embodiments of Formula II, both b=5 and R.sup.1 is
D.
[0059] In some embodiments, at least one of Ar.sup.1 through
Ar.sup.4 has Formula III:
##STR00003##
where: [0060] R.sup.2 is the same or different at each occurrence
and is selected from the group consisting of D, alkyl, alkoxy,
aryl, silyl, and siloxane, or adjacent R.sup.2 groups can be joined
to form an aromatic ring; [0061] c is the same or different at each
occurrence and is an integer from 0-4; [0062] d is the same or
different at each occurrence and is an integer from 0-5; and [0063]
m is the same or different at each occurrence and is an integer
from 0 to 6.
[0064] In some embodiments, at least one of Ar.sup.1 through
Ar.sup.4 has Formula IV:
##STR00004##
where: [0065] R.sup.2 is the same or different at each occurrence
and is selected from the group consisting of D, alkyl, alkoxy, and
aryl, or adjacent R.sup.2 groups can be joined to form an aromatic
ring; [0066] c is the same or different at each occurrence and is
an integer from 0-4; [0067] d is the same or different at each
occurrence and is an integer from 0-5; and [0068] m is the same or
different at each occurrence and is an integer from 0 to 6.
[0069] In some embodiments, Ar.sup.1 through Ar.sup.4 is selected
from the group consisting of phenyl, biphenyl, terphenyl, naphthyl,
phenylnapthyl, naphthylphenyl, and binaphthyl.
[0070] In some embodiments, Ar.sup.1 through Ar.sup.4 are
perdeuterated.
[0071] In some embodiments, Ar.sup.1 through Ar.sup.4 are
perdeuterated, except for one alkyl group on a terminal aryl.
[0072] In some embodiments, the compounds are symmetrical with
respect to the diarylamino groups. In this case, Ar.sup.1=Ar.sup.3,
and Ar.sup.2=Ar.sup.4.
[0073] In some embodiments, the compounds are non-symmetrical with
respect to the diarylamino groups. In this case, Ar.sup.1 is
different from both Ar.sup.3 and Ar.sup.4. In some embodiments,
Ar.sup.2 is also different from both Ar.sup.3 and Ar.sup.4.
[0074] Some non-limiting examples of compounds having Formula I
include Compounds E1 and E2 below:
##STR00005##
[0075] Some non-limiting examples of compounds having Formula II
include Compounds E3 through E9 below:
##STR00006## ##STR00007##
[0076] The non-deuterated analog compounds can be made using any
technique that will yield a C--C or C--N bond. A variety of such
techniques are known, such as Suzuki, Yamamoto, Stille, and Pd- or
Ni-catalyzed C--N couplings. The new deuterated compound can then
be prepared in a similar manner using deuterated precursor
materials or, more generally, by treating the non-deuterated
compound with deuterated solvent, such as d6-benzene, in the
presence of a Lewis acid H/D exchange catalyst, such as aluminum
trichloride or ethyl aluminum chloride. Exemplary preparations are
given in the Examples. The level of deuteration can be determined
by NMR analysis and by mass spectrometry, such as Atmospheric
Solids Analysis Probe Mass Spectrometry (ASAP-MS).
[0077] The compounds described herein can be formed into films
using liquid deposition techniques. Surprisingly and unexpectedly,
these compounds have greatly improved properties when compared to
analogous non-deuterated compounds. Electronic devices including an
active layer with the compounds described herein, have greatly
improved lifetimes. In addition, the lifetime increases are
achieved in combination with high quantum efficiency and good color
saturation. Furthermore, the deuterated compounds described herein
have greater air tolerance than the non-deuterated analogs. This
can result in greater processing tolerance both for the preparation
and purification of the materials and in the formation of
electronic devices using the materials.
[0078] The new deuterated compounds described herein have utility
as hole transport materials, as electroluminescent materials, and
as hosts for elecgtroluminescent materials.
3. Electronic Device
[0079] Organic electronic devices that may benefit from having one
or more layers comprising the electroluminescent materials
described herein include, but are not limited to, (1) devices that
convert electrical energy into radiation (e.g., a light-emitting
diode, light emitting diode display, or diode laser), (2) devices
that detect signals through electronics processes (e.g.,
photodetectors, photoconductive cells, photoresistors,
photoswitches, phototransistors, phototubes, IR detectors), (3)
devices that convert radiation into electrical energy, (e.g., a
photovoltaic device or solar cell), and (4) devices that include
one or more electronic components that include one or more organic
semi-conductor layers (e.g., a transistor or diode).
[0080] One illustration of an organic electronic device structure
is shown in FIG. 1. The device 100 has a first electrical contact
layer, an anode layer 110 and a second electrical contact layer, a
cathode layer 160, and an electroactive layer 140 between them.
Adjacent to the anode is a buffer layer 120. Adjacent to the buffer
layer is a hole transport layer 130, comprising hole transport
material. Adjacent to the cathode may be an electron transport
layer 150, comprising an electron transport material. As an option,
devices may use one or more additional hole injection or hole
transport layers (not shown) next to the anode 110 and/or one or
more additional electron injection or electron transport layers
(not shown) next to the cathode 160.
[0081] Layers 120 through 150 are individually and collectively
referred to as the active layers.
[0082] In one embodiment, the different layers have the following
range of thicknesses: anode 110, 500-5000 .ANG., in one embodiment
1000-2000 .ANG.; buffer layer 120, 50-2000 .ANG., in one embodiment
200-1000 .ANG.; hole transport layer 130, 50-2000 .ANG., in one
embodiment 200-1000 .ANG.; electroactive layer 140, 10-2000 .ANG.,
in one embodiment 100-1000 .ANG.; layer 150, 50-2000 .ANG., in one
embodiment 100-1000 .ANG.; cathode 160, 200-10000 .ANG., in one
embodiment 300-5000 .ANG.. The location of the electron-hole
recombination zone in the device, and thus the emission spectrum of
the device, can be affected by the relative thickness of each
layer. The desired ratio of layer thicknesses will depend on the
exact nature of the materials used.
[0083] Depending upon the application of the device 100, the
electroactive layer 140 can be a light-emitting layer that is
activated by an applied voltage (such as in a light-emitting diode
or light-emitting electrochemical cell), or a layer of material
that responds to radiant energy and generates a signal with or
without an applied bias voltage (such as in a photodetector).
Examples of photodetectors include photoconductive cells,
photoresistors, photoswitches, phototransistors, and phototubes,
and photovoltaic cells, as these terms are described in Markus,
John, Electronics and Nucleonics Dictionary, 470 and 476
(McGraw-Hill, Inc. 1966).
[0084] In some embodiments, the new deuterated compounds are useful
as hole transport materials in layer 130. In some embodiments, at
least one additional layer includes a deuterated material. In some
embodiments, the additional layer is the buffer layer 120. In some
embodiments, the additional layer is the electroactive layer 140.
In some embodiments, the additional layer is the electron transport
layer 150.
[0085] In some embodiments, the new deuterated compounds are useful
as host materials for electroactive materials in electroactive
layer 140. In some embodiments, the emissive material is also
deuterated. In some embodiments, at least one additional layer
includes a deuterated material. In some embodiments, the additional
layer is the buffer layer 120. In some embodiments, the additional
layer is the hole transport layer 130. In some embodiments, the
additional layer is the electron transport layer 150.
[0086] In some embodiments, the new deuterated compounds are useful
as electroactive materials in electroactive layer 140. In some
embodiments, a host is also present in the electroactive layer. In
some embodiments, the host material is also deuterated. In some
embodiments, at least one additional layer includes a deuterated
material. In some embodiments, the additional layer is the buffer
layer 120. In some embodiments, the additional layer is the hole
transport layer 130. In some embodiments, the additional layer is
the electron transport layer 150
[0087] In some embodiments, the new deuterated compounds are useful
as electron transport materials in layer 150. In some embodiments,
at least one additional layer includes a deuterated material. In
some embodiments, the additional layer is the buffer layer 120. In
some embodiments, the additional layer is the hole transport layer
130. In some embodiments, the additional layer is the electroactive
layer 140.
[0088] In some embodiments, an electronic device has deuterated
materials in any combination of layers selected from the group
consisting of the buffer layer, the hole transport layer, the
electroactive layer, and the electron transport layer.
[0089] In some embodiments, the devices have additional layers to
aid in processing or to improve functionality. Any or all of these
layers can include deuterated materials. In some embodiments, all
the organic device layers comprise deuterated materials. In some
embodiments, all the organic device layers consist essentially of
deuterated materials.
a. Electroactive Layer
[0090] The new deuterated compounds described herein are useful as
electroactive materials in layer 140. The compounds can be used
alone, or in combination with a host material.
[0091] In some embodiments, the electroactive layer consists
essentially of a host material and the new deuterated compound
described herein.
[0092] In some embodiments, the host is a bis-condensed cyclic
aromatic compound.
[0093] In some embodiments, the host is an anthracene derivative
compound. In some embodiments the compound has the formula:
An-L-An
where: [0094] An is an anthracene moiety; [0095] L is a divalent
connecting group. In some embodiments of this formula, L is a
single bond, --O--, --S--, --N(R)--, or an aromatic group. In some
embodiments, An is a mono- or diphenylanthryl moiety.
[0096] In some embodiments, the host has the formula:
A-An-A
where: [0097] An is an anthracene moiety; [0098] A is the same or
different at each occurrence and is an aromatic group.
[0099] In some embodiments, the A groups are attached at the 9- and
10-positions of the anthracene moiety. In some embodiments, A is
selected from the group consisting naphthyl, naphthylphenylene, and
naphthylnaphthylene. In some embodiments the compound is
symmetrical and in some embodiments the compound is
non-symmetrical.
[0100] In some embodiments, the host has the formula:
##STR00008##
where: [0101] A.sup.1 and A.sup.2 are the same or different at each
occurrence and are selected from the group consisting of H, an
aromatic group, an alkyl group and an alkenyl group, or A may
represent one or more fused aromatic rings; [0102] p and q are the
same or different and are an integer from 1-3. In some embodiments,
the anthracene derivative is non-symmetrical. In some embodiments,
p=2 and q=1. In some embodiments, at least one of A.sup.1 and
A.sup.2 is a naphthyl group. In some embodiments, additional
substituents are present.
[0103] In some embodiments, the host is selected from the group
consisting of
##STR00009##
and combinations thereof.
[0104] The new deuterated compounds described herein, in addition
to being useful as electroactive materials in the electroactive
layer, can also act as charge carrying hosts for other
electroactive materials in the electroactive layer 140. In some
embodiments, the electroactive layer consists essentially of the
new deuterated material and one or more electroactive
materials.
b. Other Device Layers
[0105] The other layers in the device can be made of any materials
that are known to be useful in such layers.
[0106] The anode 110, is an electrode that is particularly
efficient for injecting positive charge carriers. It can be made
of, for example, materials containing a metal, mixed metal, alloy,
metal oxide or mixed-metal oxide, or it can be a conducting
polymer, or mixtures thereof. Suitable metals include the Group 11
metals, the metals in Groups 4-6, and the Group 8-10 transition
metals. If the anode is to be light-transmitting, mixed-metal
oxides of Groups 12, 13 and 14 metals, such as indium-tin-oxide,
are generally used. The anode 110 can also comprise an organic
material such as polyaniline as described in "Flexible
light-emitting diodes made from soluble conducting polymer," Nature
vol. 357, pp 477-479 (11 Jun. 1992). At least one of the anode and
cathode is desirably at least partially transparent to allow the
generated light to be observed.
[0107] The buffer layer 120 comprises buffer material and may have
one or more functions in an organic electronic device, including
but not limited to, planarization of the underlying layer, charge
transport and/or charge injection properties, scavenging of
impurities such as oxygen or metal ions, and other aspects to
facilitate or to improve the performance of the organic electronic
device. Buffer materials may be polymers, oligomers, or small
molecules. They may be vapour deposited or deposited from liquids
which may be in the form of solutions, dispersions, suspensions,
emulsions, colloidal mixtures, or other compositions.
[0108] The buffer layer can be formed with polymeric materials,
such as polyaniline (PANI) or polyethylenedioxythiophene (PEDOT),
which are often doped with protonic acids. The protonic acids can
be, for example, poly(styrenesulfonic acid),
poly(2-acrylamido-2-methyl-1-propanesulfonic acid), and the
like.
[0109] The buffer layer can comprise charge transfer compounds, and
the like, such as copper phthalocyanine and the
tetrathiafulvalene-tetracyanoquinodimethane system (TTF-TCNQ).
[0110] In some embodiments, the buffer layer comprises at least one
electrically conductive polymer and at least one fluorinated acid
polymer. Such materials have been described in, for example,
published U.S. patent applications 2004-0102577, 2004-0127637, and
2005/205860
[0111] In some embodiments, the new deuterated compounds described
herein have utility as hole transport materials. Examples of other
hole transport materials for layer 130 have been summarized for
example, in Kirk-Othmer Encyclopedia of Chemical Technology, Fourth
Edition, Vol. 18, p. 837-860, 1996, by Y. Wang. Both hole
transporting molecules and polymers can be used. Commonly used hole
transporting molecules are:
N,N'-diphenyl-N,N'-bis(3-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine
(TPD), 1,1-bis[(di-4-tolylamino) phenyl]cyclohexane (TAPC),
N,N'-bis(4-methylphenyl)-N,N'-bis(4-ethylphenyl)-[1,1'-(3,3'-dimethyl)bip-
henyl]-4,4'-diamine (ETPD),
tetrakis-(3-methylphenyl)-N,N,N',N'-2,5-phenylenediamine (PDA),
a-phenyl-4-N,N-diphenylaminostyrene (TPS),
p-(diethylamino)benzaldehyde diphenylhydrazone (DEH),
triphenylamine (TPA),
bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane
(MPMP),
1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]
pyrazoline (PPR or DEASP),
1,2-trans-bis(9H-carbazol-9-yl)cyclobutane (DCZB),
N,N,N',N'-tetrakis(4-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine
(TTB), N,N'-bis(naphthalen-1-yl)-N,N'-bis-(phenyl)benzidine
(.alpha.-NPB), and porphyrinic compounds, such as copper
phthalocyanine. Commonly used hole transporting polymers are
polyvinylcarbazole, (phenylmethyl)-polysilane, and polyaniline. It
is also possible to obtain hole transporting polymers by doping
hole transporting molecules such as those mentioned above into
polymers such as polystyrene and polycarbonate. In some cases,
triarylamine polymers are used, especially triarylamine-fluorene
copolymers. In some cases, the polymers and copolymers are
crosslinkable. Examples of crosslinkable hole transport polymers
can be found in, for example, published US patent application
2005-0184287 and published PCT application WO 2005/052027. In some
embodiments, the hole transport layer is doped with a p-dopant,
such as tetrafluorotetracyanoquinodimethane and
perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride.
[0112] In some embodiments, the new deuterated compounds described
herein have utility as electron transport materials. Examples of
other electron transport materials which can be used in layer 150
include metal chelated oxinoid compounds, such as
tris(8-hydroxyquinolato)aluminum (Alq.sub.3);
bis(2-methyl-8-quinolinolato)(para-phenyl-phenolato)aluminum(III)
(BAIQ); and azole compounds such as
2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD) and
3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ),
and 1,3,5-tri(phenyl-2-benzimidazole)benzene (TPBI); quinoxaline
derivatives such as 2,3-bis(4-fluorophenyl)quinoxaline;
phenanthroline derivatives such as 9,10-diphenylphenanthroline
(DPA) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA); and
mixtures thereof. The electron-transport layer may also be doped
with n-dopants, such as Cs or other alkali metals. Layer 150 can
function both to facilitate electron transport, and also serve as a
buffer layer or confinement layer to prevent quenching of the
exciton at layer interfaces. Preferably, this layer promotes
electron mobility and reduces exciton quenching.
[0113] The cathode 160, is an electrode that is particularly
efficient for injecting electrons or negative charge carriers. The
cathode can be any metal or nonmetal having a lower work function
than the anode. Materials for the cathode can be selected from
alkali metals of Group 1 (e.g., Li, Cs), the Group 2 (alkaline
earth) metals, the Group 12 metals, including the rare earth
elements and lanthanides, and the actinides. Materials such as
aluminum, indium, calcium, barium, samarium and magnesium, as well
as combinations, can be used. Li- or Cs-containing organometallic
compounds, LiF, CsF, and Li.sub.2O can also be deposited between
the organic layer and the cathode layer to lower the operating
voltage.
[0114] It is known to have other layers in organic electronic
devices. For example, there can be a layer (not shown) between the
anode 110 and buffer layer 120 to control the amount of positive
charge injected and/or to provide band-gap matching of the layers,
or to function as a protective layer. Layers that are known in the
art can be used, such as copper phthalocyanine, silicon
oxy-nitride, fluorocarbons, silanes, or an ultra-thin layer of a
metal, such as Pt. Alternatively, some or all of anode layer 110,
active layers 120, 130, 140, and 150, or cathode layer 160, can be
surface-treated to increase charge carrier transport efficiency.
The choice of materials for each of the component layers is
preferably determined by balancing the positive and negative
charges in the emitter layer to provide a device with high
electroluminescence efficiency.
[0115] It is understood that each functional layer can be made up
of more than one layer.
[0116] The device can be prepared by a variety of techniques,
including sequential vapor deposition of the individual layers on a
suitable substrate. Substrates such as glass, plastics, and metals
can be used. Conventional vapor deposition techniques can be used,
such as thermal evaporation, chemical vapor deposition, and the
like. Alternatively, the organic layers can be applied from
solutions or dispersions in suitable solvents, using conventional
coating or printing techniques, including but not limited to
spin-coating, dip-coating, roll-to-roll techniques, ink-jet
printing, screen-printing, gravure printing and the like.
[0117] To achieve a high efficiency LED, the HOMO (highest occupied
molecular orbital) of the hole transport material desirably aligns
with the work function of the anode, and the LUMO (lowest
un-occupied molecular orbital) of the electron transport material
desirably aligns with the work function of the cathode. Chemical
compatibility and sublimation temperature of the materials are also
important considerations in selecting the electron and hole
transport materials.
[0118] It is understood that the efficiency of devices made with
the chrysene compounds described herein, can be further improved by
optimizing the other layers in the device. For example, more
efficient cathodes such as Ca, Ba or LiF can be used. Shaped
substrates and novel hole transport materials that result in a
reduction in operating voltage or increase quantum efficiency are
also applicable. Additional layers can also be added to tailor the
energy levels of the various layers and facilitate
electroluminescence.
[0119] The compounds of the invention often are fluorescent and
photoluminescent and can be useful in applications other than
OLEDs, such as oxygen sensitive indicators and as fluorescent
indicators in bioassays.
EXAMPLES
[0120] The following examples illustrate certain features and
advantages of the present invention. They are intended to be
illustrative of the invention, but not limiting. All percentages
are by weight, unless otherwise indicated.
Comparative Example A
[0121] This example illustrates the preparation of a non-deuterated
electroluminescent material, Comparative Compound A.
##STR00010##
(a) Preparation of 1-(4-tert-butylstyryl)naphthalene
[0122] An oven-dried 500 ml three-neck round bottom flask was
equipped with a magnetic stir bar, addition funnel and nitrogen
inlet connector. The flask was charged with
(1-napthylmethyl)triphenylphosphonium chloride (12.07 g, 27.5 mmol)
and 200 ml of anhydrous THF. Sodium hydride (1.1 g, 25 mmol) was
added in one portion. The mixture became bright orange and was left
to stir overnight at room tempearture. A solution of
4-tert-butyl-benzaldehyde (7.1 g, 25 mmol) in anhydrous THF (30 ml)
was added to the addition funnel with a cannula. The aldehyde
solution was added to the reaction mixture dropwise over 45
minutes. Reaction was left to stir at room temperature for 24 hours
(orange color went away). Silica gel was added to the reaction
mixture and volatiles were removed under reduced pressure. The
crude product was purified by column chromatography on silica gel
using 5-10% dichloromethane in hexanes. The product was isolated as
a mixture of cis- and trans-isomers (6.3 g, 89%) and used without
separation. The structure was confirmed by .sup.1H NMR.
(b) Preparation of 3-tert-butylchrysene
[0123] 1-(4-tert-Butylstyryl)naphthalenes (4.0 g, 14.0 mmol) were
dissolved in dry toluene (1 l) in a one-liter photochemical vessel,
equipped with nitrogen inlet and a stirbar. A bottle of dry
propylene oxide was cooled in ice-water before 100 ml of the
epoxide was withdrawn with a syringe and added to the reaction
mixture. Iodine (3.61 g, 14.2 mmol) was added last. Condenser was
attached on top of the photochemical vessel and halogen lamp
(Hanovia, 450 W) was turned on. Reaction was stopped by turning off
the lamp when no more iodine was left in the reaction mixture, as
evidenced by the disappearance of its color. The reaction was
complete in 3.5 hours. Toluene and excess propylene oxide were
removed under reduced pressure to yield a dark yellow solid. Crude
product was dissolved in a small amount of 25% dichloromethane in
hexane, passed through a 4'' plug of neutral alumina, and washed
with 25% dichloromethane in hexane (about one liter). Volatiles
were removed to give 3.6 g (91%) of 3-tert-butylchrysene as a
yellow solid. The structure was confirmed by .sup.1H NMR.
(c) Preparation of 6,12-dibromo-3-tert-butylchrysene
[0124] 3-tert-Butylchrysene (4.0 g, 14.1 mmol) and
trimethylphosphate (110 ml) were mixed in a 500 ml round-bottom
flask. After bromine (4.95 g, 31 mmol) was added, a reflux
condenser was attached to the flask and reaction mixture was
stirred for one hour in an oil bath at 105.degree. C. A white
precipitate formed almost immediately. Reaction mixture was worked
up by pouring it onto a small amount of ice water (100 ml). The
mixture was vacuum-filtered and washed well with water. The
resulting tan solid was dried under vacuum. The crude product was
boiled in methanol (100 ml), cooled to room temperature and
filtered again to yield 3.74 g (60%) of a white solid. The
structure was confirmed by .sup.1H NMR.
(d) Preparation of
3-tert-butyl-N.sup.6,N.sup.6,N.sup.12,N.sup.12-tetraphenylchrysene-6,12-d-
iamine, Comparative Compound A
[0125] In a drybox, 6,12-dibromo-3-tert-butylchrysene (0.8 g, 1.81
mmol) and diphenylamine (1.22 g, 7.2 mmol) were combined in a 500
ml round-bottom flask and dissolved in 10 ml of dry toluene.
2-Biphenyl-di-tert-butylphosphine (0.072 g, 0.04 mmol) and
tris(dibenzylideneacetone)dipalladium(0) (0.036 g, 0.02 mmol) were
dissolved in 5 ml of dry toluene and stirred for 10 minutes. The
catalyst solution was added to the reaction mixture, stirred for 10
minutes and followed by sodium tert-butoxide (0.35 g, 3.62 mmol)
and 5 ml of dry toluene. After another 10 minutes, the reaction
flask was brought out of the drybox, attached to a nitrogen line
and stirred at 110.degree. C. overnight. Next day, reaction mixture
was cooled to room temperature and filtered through a two-inch plug
of silica gel and Celite, washing with 500 ml of dichloromethane.
Removal of volatiles under reduced pressure gave a dark brown oil.
The crude product was further purified by flash chromatography on
silica gel using Isolera purification system from Biotage. The
resulting solid was washed with methanol and then recrystallized
from hot hexane to yield 0.26 g (25%) of the product. The structure
was confirmed by .sup.1H NMR.
Example 1
[0126] This example illustrates the preparation of a compound
having Formula II, Compound E3.
##STR00011##
[0127] This compound was prepared from
6,12-dibromo-3-tert-butylchrysene and di(perdeuterophenyl)amine
using the procedure described above for Comparative Compound A.
Yield 0.37 g (36%). The structure of Compound E3 was confirmed by
.sup.1H NMR.
Comparative Example B
[0128] This example illustrates the preparation of a non-deuterated
electroluminescent material, Comparative Compound B
##STR00012##
0.45 g of 2,6-di-t-butyl-9,10-dibromoanthracene (1 mM) (Muller, U.;
Adam, M.; Mullen, K. Chem. Ber. 1994, 127, 437-444) was placed in a
round bottom flask in a nitrogen filled glove box and 0.38 g (2.2
mM) diphenylamine and 0.2 g sodium tert-butoxide (2 mM) with 40 mL
toluene were added. 0.15 g Pd.sub.2DBA.sub.3 (0.15 mM) and 0.07 g
P(t-Bu)3 (0.3 mM) were dissolved in 10 mL toluene and added to the
first solution with stirring. When all materials are mixed the
solution slowly exotherms and becomes yellow brown. The solution
was stirred and heated in the glove box at 80 C under nitrogen for
1 hr. The solution immediately is dark purple but on reaching
.about.80 C it is dark yellow green with a noticeable green
luminescence. After cooling to room temperature the solution is
removed from the glove box and filtered through a short
basic-alumina plug eluting with toluene to give a bright
yellow-green band. Evaporation and recrystallization from
toluene/methanol gave the expected product as confirmed by 1-H nmr,
in yield of 0.55 g
Example 2
[0129] This example illustrates the preparation of a compound
having Formula I, Compound E1.
##STR00013##
This compound was prepared from
9,10-dibromo-2,6di-tert-butylanthracene and
di(perdeuterophenyl)amine using the procedure described above for
Comparative Compound B. Yield 0.55 g. The structure of Compound E1
was confirmed by .sup.1H NMR.
Example 3 and Comparative Example C
[0130] These examples demonstrate the fabrication and performance
of a device with a blue emitter. The following materials were
used:
##STR00014##
[0131] The device had the following structure on a glass
substrate:
[0132] anode=Indium Tin Oxide (ITO): 50 nm
[0133] buffer layer=Buffer 1 (50 nm), which is an aqueous
dispersion of an electrically conductive polymer and a polymeric
fluorinated sulfonic acid. Such materials have been described in,
for example, published U.S. patent applications US 2004/0102577, US
2004/0127637, and US 2005/0205860.
[0134] hole transport layer=polymer P1 (20 nm)
[0135] electroactive layer=13:1 host H1:dopant (40 nm)
[0136] electron transport layer=a metal quinolate derivative (10
nm)
[0137] cathode=CsF/AI (0.7/100 nm)
[0138] OLED devices were fabricated by a combination of solution
processing and thermal evaporation techniques. Patterned indium tin
oxide (ITO) coated glass substrates from Thin Film Devices, Inc
were used. These ITO substrates are based on Corning 1737 glass
coated with ITO having a sheet resistance of 30 ohms/square and 80%
light transmission. The patterned ITO substrates were cleaned
ultrasonically in aqueous detergent solution and rinsed with
distilled water. The patterned ITO was subsequently cleaned
ultrasonically in acetone, rinsed with isopropanol, and dried in a
stream of nitrogen.
[0139] Immediately before device fabrication the cleaned, patterned
ITO substrates were treated with UV ozone for 10 minutes.
Immediately after cooling, an aqueous dispersion of Buffer 1 was
spin-coated over the ITO surface and heated to remove solvent.
After cooling, the substrates were then spin-coated with a solution
of a hole transport material, and then heated to remove solvent.
After cooling the substrates were spin-coated with the emissive
layer solution, and heated to remove solvent. The substrates were
masked and placed in a vacuum chamber. The electron transport layer
was deposited by thermal evaporation, followed by a layer of CsF.
Masks were then changed in vacuo and a layer of Al was deposited by
thermal evaporation. The chamber was vented, and the devices were
encapsulated using a glass lid, dessicant, and UV curable
epoxy.
[0140] The OLED samples were characterized by measuring their (1)
current-voltage (I-V) curves, (2) electroluminescence radiance
versus voltage, and (3) electroluminescence spectra versus voltage.
All three measurements were performed at the same time and
controlled by a computer. The current efficiency of the device at a
certain voltage is determined by dividing the electroluminescence
radiance of the LED by the current density needed to run the
device. The unit is a cd/A. The power efficiency is the current
efficiency divided by the operating voltage. The unit is 1 m/W. The
device data is given in Table 1.
TABLE-US-00001 TABLE 1 Device Performance CE Voltage CIE CIE Lum.
1/2 Example Dopant [cd/A] (V) [x] [y] Life [h] Comp. Ex. C
Comparative A 2.9 4.9 0.144 0.080 400 Ex. 3 Compound E3 2.9 4.9
0.145 0.081 1175 * All data @ 1000 nits, CE = current efficiency;
CIEx and CIEy are the x and y color coordinates according to the
C.I.E. chromaticity scale (Commission Internationale de
L'Eclairage, 1931). Lum. 1/2 Life is defined as the time in hours
for a device to reach one-half the initial luminance.
[0141] The relative lifetime of devices made with the chrysene
dopants having Formula II are significantly better than devices
made with comparative Compound A.
Example 4 and Comparative Example D
[0142] These examples demonstrate the fabrication and performance
of a device with a green emitter.
[0143] The device had the following structure on a glass
substrate:
[0144] anode=ITO (180 nm)
[0145] buffer layer=Buffer 1 (50 nm)
[0146] hole transport layer=polymer P1 (20 nm)
[0147] electroactive layer=13:1 host H1:dopant (60 nm)
[0148] electron transport layer=a metal quinolate derivative (10
nm)
[0149] cathode=CsF/AI (1.0/100 nm)
OLED devices were fabricated as described above for Example 3. The
device data (average of three devices) is given in Table 2.
TABLE-US-00002 TABLE 2 Device Performance CE Voltage CIE CIE Lum.
1/2 Example Dopant [cd/A] (V) [x] [y] Life [h] Comp. Ex. D
Comparative B 15.5 4.7 0.20 0.61 19,494 Ex. 2 Compound E1 17.5 4.3
0.19 0.60 56,670
[0150] The relative lifetime of devices made with the anthracene
dopants having Formula I are significantly better than devices made
with the anthracene dopant comparative Compound B.
[0151] Note that not all of the activities described above in the
general description or the examples are required, that a portion of
a specific activity may not be required, and that one or more
further activities may be performed in addition to those described.
Still further, the order in which activities are listed are not
necessarily the order in which they are performed.
[0152] In the foregoing specification, the concepts have been
described with reference to specific embodiments. However, one of
ordinary skill in the art appreciates that various modifications
and changes can be made without departing from the scope of the
invention as set forth in the claims below. Accordingly, the
specification and figures are to be regarded in an illustrative
rather than a restrictive sense, and all such modifications are
intended to be included within the scope of invention.
[0153] Benefits, other advantages, and solutions to problems have
been described above with regard to specific embodiments. However,
the benefits, advantages, solutions to problems, and any feature(s)
that may cause any benefit, advantage, or solution to occur or
become more pronounced are not to be construed as a critical,
required, or essential feature of any or all the claims.
[0154] It is to be appreciated that certain features are, for
clarity, described herein in the context of separate embodiments,
may also be provided in combination in a single embodiment.
Conversely, various features that are, for brevity, described in
the context of a single embodiment, may also be provided separately
or in any subcombination. Further, reference to values stated in
ranges include each and every value within that range.
* * * * *