U.S. patent application number 13/607322 was filed with the patent office on 2013-01-03 for organic photoelectric conversion material and organic thin-film photoelectric conversion device.
This patent application is currently assigned to FUJIFILM CORPORATION. Invention is credited to Tetsu KITAMURA.
Application Number | 20130005963 13/607322 |
Document ID | / |
Family ID | 41378279 |
Filed Date | 2013-01-03 |
United States Patent
Application |
20130005963 |
Kind Code |
A1 |
KITAMURA; Tetsu |
January 3, 2013 |
ORGANIC PHOTOELECTRIC CONVERSION MATERIAL AND ORGANIC THIN-FILM
PHOTOELECTRIC CONVERSION DEVICE
Abstract
An organic photoelectric conversion material for use in an
organic thin-film photoelectric conversion device, containing a
compound represented by formula 1; and an organic thin-film
photoelectric conversion device having a photoelectric conversion
layer which containing the organic photoelectric conversion
material: ##STR00001## wherein D represents an electron-donating
aromatic substituent whose bonding site atom is a sp.sup.2 carbon
atom; and a plurality of D may be the same or different from each
other.
Inventors: |
KITAMURA; Tetsu;
(Ashigarakami-gun, JP) |
Assignee: |
FUJIFILM CORPORATION
Tokyo
JP
|
Family ID: |
41378279 |
Appl. No.: |
13/607322 |
Filed: |
September 7, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12474937 |
May 29, 2009 |
|
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13607322 |
|
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Current U.S.
Class: |
544/82 ; 546/165;
546/174; 546/94; 548/100; 548/156; 548/219; 548/427; 548/455 |
Current CPC
Class: |
C07D 417/10 20130101;
C07D 403/10 20130101; H01L 51/0068 20130101; H01L 51/005 20130101;
H01L 51/0067 20130101; C07D 471/04 20130101; C07D 401/10 20130101;
H01L 51/4253 20130101; B82Y 10/00 20130101; C07D 407/10 20130101;
C07D 413/10 20130101; H01L 51/0059 20130101; C07D 409/10 20130101;
H01L 51/0047 20130101 |
Class at
Publication: |
544/82 ; 548/455;
548/427; 548/219; 548/156; 548/100; 546/174; 546/165; 546/94 |
International
Class: |
C07D 403/08 20060101
C07D403/08; C07D 417/08 20060101 C07D417/08; C07D 413/14 20060101
C07D413/14; C07D 401/08 20060101 C07D401/08; C07D 471/06 20060101
C07D471/06; C07D 413/08 20060101 C07D413/08; C07D 421/08 20060101
C07D421/08 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2008 |
JP |
2008-143256 |
Claims
1. An organic photoelectric conversion material for use in an
organic thin-film photoelectric conversion device, comprising a
compound represented by formula 1: ##STR00016## wherein D
represents an electron-donating aromatic substituent whose bonding
site atom is a sp.sup.2 carbon atom; and a plurality of D may be
the same or different from each other.
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. (canceled)
10. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Divisional of application Ser. No. 12/474,937
filed May 29, 2009, which claims benefit to Japanese Patent
Application No. 2008-143256 filed May 30, 2008. The above-noted
applications are incorporated herein by reference in their
entirety.
SUMMARY OF THE INVENTION
[0002] The present invention relates to an organic photoelectric
conversion material containing a compound having a particular
chemical structure, and to a high-performance organic thin-film
photoelectric conversion device using the organic photoelectric
conversion material.
FIELD OF THE INVENTION
[0003] The present invention relates to an organic photoelectric
conversion material containing a compound having a particular
chemical structure, and to a high-performance organic thin-film
photoelectric conversion device using the organic photoelectric
conversion material.
BACKGROUND OF THE INVENTION
[0004] With the arrival of a ubiquitous information society, an
information terminal is demanded to transfer information anytime,
anywhere. For such a terminal, flexible, light-weight, and
inexpensive electronic devices are required, but the conventional
devices using inorganic semiconductor materials such as silicon
does not sufficiently meet the requirement. Accordingly, in recent
years, electronic devices using organic semiconductor materials as
semiconductors are intensively studied for satisfying such
requirements (see, for example, Chemical Reviews, 2007, 107, p.
1296-1323, and "Organic Field-Effect Transistors", 2007, CRC Press,
p. 159-228).
[0005] Organic semiconductor materials are used as a photoelectric
conversion material thereby obtaining organic photoelectric
conversion devices such as optical sensors (see, for example,
JP-A-2003-234460, JP-A-2003-332551, and JP-A-2005-268609 ("JP-A"
means unexamined published Japanese patent application)), or
organic thin-film solar cells (see, for example, "Organic
Photovoltaics" (published in 2005, Taylor & Francis), p.
49-104, and Chemical Reviews, 2007, 107, p. 1324-1338). These
organic photoelectric conversion devices are easier to produce as
compared to the devices using inorganic semiconductor materials
such as silicon. Especially, when an organic semiconductor material
capable of performing film production according to a wet process is
used, it is possible to manufacture large-scale devices at a low
cost under a low temperature. There is ever reported, for example,
the organic photoelectric conversion device using a photoelectric
conversion layer that is a wet-process formed blend film composed
of P3HT (poly(3-hexylthiophene)) and PCBM
([6,6]-phenyl-C.sub.61-butyric acid methyl ester). However, the
photoelectric conversion performance of the conventional organic
photoelectric conversion device is inferior to that of a silicon
photoelectric conversion device. Therefore, improvement in
performance of the organic photoelectric conversion device is
demanded. The most outstanding issue to improvement in performance
is that especially a long wavelength range (near infrared range)
has not been used in the current device using both P3HT and PCBM
because of a narrow light absorption wavelength range of the
materials that are used in the device. Resultantly, energy
conversion efficiency is low for use of the solar cell, and
sensitivity that is required for an optical sensor is not provided
in the long wavelength range (near infrared range). For this
reason, it is required to develop an organic photoelectric
conversion material capable of absorbing light even in a longer
wavelength range (near infrared range), and capable of providing
photoelectric conversion performance (see, for example, "Organic
Photovoltaics" (published in 2005, Taylor & Francis), p.
49-104, and Chemical Reviews, 2007, 107, p. 1324-1338).
[0006] As a material capable of absorbing light even in a near
infrared range, croconium dyes are known (see, for example,
JP-A-2001-117201, and Dyes and Pigments, 1988, 10, p. 13-22).
However, there is no specific description in which the croconium
dye is actually used in an organic photoelectric conversion device.
Consequently, no photoelectric conversion performance is
confirmed.
SUMMARY OF THE INVENTION
[0007] The present invention resides in an organic photoelectric
conversion material for use in an organic thin-film photoelectric
conversion device, which comprises a compound represented by
formula 1:
##STR00002##
[0008] wherein D represents an electron-donating aromatic
substituent whose bonding site atom is a sp.sup.2 carbon atom; and
a a plurality of D may be the same or different from each
other.
[0009] Further, the present invention resides in an organic
thin-film photoelectric conversion device, having two electrode
layers and an organic thin-film photoelectric conversion layer,
wherein the photoelectric conversion layer comprises the organic
photoelectric conversion material comprising the compound
represented by formula 1.
[0010] The inventor has found that it is possible to provide
following specific photoelectric conversion materials and the
following high-performance organic thin-layer photoelectric
conversion device using the organic photoelectric conversion
material.
[0011] According to the present invention, there is provided the
following means:
(1) An organic photoelectric conversion material for use in an
organic thin-film photoelectric conversion device, comprising a
compound represented by formula 1:
##STR00003##
[0012] wherein D represents an electron-donating aromatic
substituent whose bonding site atom is a sp.sup.2 carbon atom; and
a plurality of D may be the same or different from each other.
(2) An organic thin-film photoelectric conversion device, having
two electrode layers and an organic thin-film photoelectric
conversion layer, wherein the photoelectric conversion layer
comprises the organic photoelectric conversion material as
described in (1). (3) The organic thin-film photoelectric
conversion device as described in (2), wherein the photoelectric
conversion layer comprises an n-type organic semiconductor material
in addition to the organic photoelectric conversion material. (4)
The organic thin-film photoelectric conversion device as described
in (3), wherein the photoelectric conversion layer has a blend film
comprising both the organic photoelectric conversion material and
the n-type organic semiconductor material. (5) The organic
thin-film photoelectric conversion device as described in (3) or
(4), wherein the n-type organic semiconductor material is at least
one compound selected from the group consisting of a fullerene
compound, a phthalocyanine compound, a naphthalene tetracarbonyl
compound, and a perylene tetracarbonyl compound. (6) The organic
thin-film photoelectric conversion device as described in any one
of (3) to (5), wherein the n-type organic semiconductor material is
a fullerene compound. (7) The organic thin-film photoelectric
conversion device as described in any one of (2) to (6), wherein a
film of the photoelectric conversion layer is formed by a
solution-coating method. (8) The organic thin-film photoelectric
conversion device as described in (7), wherein a solvent in the
solution-coating method contains at least one solvent having a
boiling point of 135.degree. C. or more and less than 300.degree.
C. (9) The organic thin-film photoelectric conversion device as
described in any one of (2) to (8), further having a buffer layer
containing an electrically conductive polymer, the buffer layer
being disposed between at least one of the electrode layers and the
organic photoelectric conversion layer. (10) The organic thin-film
photoelectric conversion device as described in any one of (2) to
(9), which is sealed under an inert atmosphere after production of
the organic thin-film photoelectric conversion device.
[0013] According to the present invention, it is possible to obtain
an organic photoelectric conversion material capable of forming a
film by using a coating method, and capable of providing a good
photoelectric conversion performance even in a long wavelength
range (near infrared range). Further, a high-performance organic
thin-film photoelectric conversion device with sensitivity in the
near infrared range may be obtained by using the organic
photoelectric conversion material.
[0014] Other and further features and advantages of the invention
will appear more fully from the following description,
appropriately referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a cross-sectional view schematically showing a
structure of an embodiment of the organic thin-film photoelectric
conversion device of the present invention.
[0016] FIG. 2 is a graph showing current-voltage characteristics of
the organic thin-layer photoelectric conversion device of the
present invention using the exemplified compound 1, in two cases
where the near infrared light is not irradiated and the near
infrared light is irradiated.
[0017] FIG. 3 is a graph showing an absorption spectrum of the
organic thin-layer photoelectric conversion device in which the
exemplified compound 1 is used.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The compound represented by formula 1 that is used in the
present invention is described in detail. Hereinafter the compound
represented by formula 1 may also be referred to as the organic
photoelectric conversion material of the present invention in some
cases.
##STR00004##
[0019] wherein D represents an electron-donating aromatic
substituent whose bonding site atom is a sp.sup.2 carbon atom. The
electron-donating aromatic substituent is defined as an aromatic
compound whose electron density is denser than that of the
non-substituted benzene ring, and also as the aromatic compound
that is more easily oxidized, but more hardly reduced as compared
to benzene. A plurality of D may be the same or different from each
other. From viewpoints of both photoelectric conversion performance
and solubility, the structure represented by D has preferably 3 to
30 carbon atoms, and more preferably 6 to 20 carbon atoms. D is
preferably represented by any one of the following formulae D-1 to
D-11.
##STR00005##
[0020] In the above chemical formulae, the mark "*" indicates a
bonding site.
[0021] In D-1 to D-11, A represents CR.sub.2, O, S, Se, Te, or NR.
B represents CR, or N. R represents a hydrogen atom, or a
substituent. m represents an integer. A plurality of R may be the
same or different from each other. The substituent represented by D
is not particularly limited, and may be selected from W that is
described below. The substituent is preferably a halogen atom, an
alkyl group, an aryl group, a heterocyclic group, a hydroxyl group,
a nitro group, or an amino group. A plurality of R may bond
together to form a ring. Such the embodiment is also
preferable.
[0022] Among D-1 to D-11, D-1 to D-7 are furthermore preferable.
D-1, D-2, D-3, D-4, and D-6 are especially preferable.
[0023] In the present invention, when specific moiety in the
substituent is called "group", the site itself may not be
substituted or may be substituted by one or more (to a possible
maximum number) substituents. For example, "an alkyl group" means a
substituted or unsubstituted alkyl group. Namely, the substituents
which can be used in the compound for use in the present invention
can be further substituted.
[0024] When such a substituent is set "W", the substituent
represented by W may be any substituent and is not particularly
limited, and, examples thereof include a halogen atom, an alkyl
group (including, as well as a linear or branched alkyl group, a
cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl
group,), an alkenyl group (including, as well as a linear or
branched alkenyl group, a cycloalkenyl group and a bicycloalkenyl
group), an alkynyl group, an aryl group, a heterocyclic group, a
cyano group, a hydroxyl group, a nitro group, a carboxyl group, an
alkoxy group, an aryloxy group, a silyloxy group, a heterocyclic
oxy group, an acyloxy group, a carbamoyloxy group, an
alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino
group (including an anilino group), an ammonio group, an acylamino
group, an aminocarbonylamino group, an alkoxycarbonylamino group,
an aryloxycarbonylamino group, a sulfamoylamino group, an
alkylsulfonylamino group, an arylsulfonylamino group, a mercapto
group, an alkylthio group, an arylthio group, a heterocyclic thio
group, a sulfamoyl group, a sulfo group, an alkylsulfinyl group, an
arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group,
an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a
carbamoyl group, an arylazo group, a heterocyclic azo group, an
imido group, a phosphino group, a phosphinyl group, a phosphinyloxy
group, a phosphinylamino group, a phosphono group, a silyl group, a
hydrazino group, a ureido group, a boronic acid group
(--B(OH).sub.2), a phosphate group (--OPO(OH).sub.2), a sulfate
group (--OSO.sub.3H), and other known substituents.
[0025] Specifically, the substituent represented by W represents
the group as shown in the following items (1) to (48).
(1) Halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine
atom, an iodine atom) (2) Alkyl group (which means a linear,
branched or cyclic substituted or unsubstituted alkyl group, and
examples of the alkyl group include the groups as shown in the
following items (2-a) to (2-e)) (2-a) Alkyl group (alkyl group
having preferably from 1 to 30, more preferably from 1 to 20,
carbon atoms, e.g., methyl, ethyl, n-propyl, isopropyl, tert-butyl,
n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl) (2-b)
Cycloalkyl group (preferably a substituted or unsubstituted
cycloalkyl group having from 3 to 30, more preferably from 3 to 20,
carbon atoms, e.g., cyclohexyl, cyclopentyl,
4-n-dodecyl-cyclohexyl) (2-c) Bicycloalkyl group (preferably a
substituted or unsubstituted bicycloalkyl group having from 5 to
30, more preferably from 5 to 20, carbon atoms, e.g.,
bicyclo[1,2,2]heptan-2-yl, bicyclo[2,2,2]octan-3-yl) (2-d)
Tricycloalkyl group (preferably a substituted or unsubstituted
tricycloalkyl group having from 7 to 30, more preferably from 7 to
20, carbon atoms, e.g., 1-adamantyl) (2-e) Polycycloalkyl group
having 4 or more cyclic structures
[0026] The alkyl group in the substituents described below (for
example, an alkyl group in an alkylthio group) means an alkyl group
having such a concept and further includes an alkenyl group and an
alkynyl group.
(3) Alkenyl group (which means a linear, branched or cyclic
substituted or unsubstituted alkenyl group, and examples of the
alkenyl group include the groups as shown in the following items
(3-a) to (3-c)) (3-a) Alkenyl group (preferably a substituted or
unsubstituted alkenyl group having from 2 to 30, more preferably
from 2 to 20, carbon atoms, e.g., vinyl, allyl, prenyl, geranyl,
oreyl) (3-b) Cycloalkenyl group (preferably a substituted or
unsubstituted cycloalkenyl group having from 3 to 30, more
preferably from 3 to 20, carbon atoms, e.g., 2-cyclopenten-1-yl,
2-cyclohexen-1-yl) (3-c) Bicycloalkenyl group (a substituted or
unsubstituted bicycloalkenyl group, preferably a substituted or
unsubstituted bicycloalkenyl group having from 5 to 30, more
preferably from 5 to 20, carbon atoms, e.g.,
bicyclo[2,2,1]hept-2-en-1-yl, bicyclo[2,2,2]oct-2-en-4-yl) (4)
Alkynyl group (preferably a substituted or unsubstituted alkynyl
group having from 2 to 30, more preferably from 2 to 20, carbon
atoms, e.g., ethynyl, propargyl, trimethylsilylethynyl) (5) Aryl
group (preferably a substituted or unsubstituted aryl group having
from 6 to 30, more preferably from 6 to 20, carbon atoms, e.g.,
phenyl, p-tolyl, naphthyl, m-chlorophenyl,
o-hexadecanoylaminophenyl, ferrocenyl) (6) Heterocyclic group
(preferably a monovalent group resultant from removing one hydrogen
atom of a 5- or 6-membered substituted or unsubstituted aromatic or
non-aromatic heterocyclic compound, more preferably a 5- or
6-membered aromatic heterocyclic group having from 2 to 50 carbon
atoms, and their hetero atoms of thereof include N, O, Se, Te, Si
and Ge; e.g., 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl;
the heterocyclic group may also be a cationic heterocyclic group
such as 1-methyl-2-pyridinio and 1-methyl-2-quinolinio) (7) Cyano
group (8) Hydroxyl group (9) Nitro group (10) Carboxyl group (11)
Alkoxy group (preferably a substituted or unsubstituted alkoxy
group having from 1 to 30, more preferably from 1 to 20, carbon
atoms, e.g., methoxy, ethoxy, isopropoxy, tert-butoxy, n-octyloxy,
2-methoxyethoxy) (12) Aryloxy group (preferably a substituted or
unsubstituted aryloxy group having from 6 to 30, more preferably
from 6 to 20, carbon atoms, e.g., phenoxy, 2-methylphenoxy,
4-tert-butylphenoxy, 3-nitrophenoxy, 2-tradecanoylaminophenoxy)
(13) Silyloxy group (preferably a silyloxy group having from 3 to
30, more preferably from 2 to 20, carbon atoms, e.g.,
trimethylsilyloxy, tert-butyldimethylsilyloxy) (14) Heterocyclic
oxy group (preferably a substituted or unsubstituted heterocyclic
oxy group having from 2 to 30, more preferably from 2 to 20, carbon
atoms, e.g., 1-phenyltetrazol-5-oxy, 2-tetrahydropyranyloxy) (15)
Acyloxy group (preferably a formyloxy group, a substituted or
unsubstituted alkylcarbonyloxy group having from 2 to 30, more
preferably from 2 to 20, carbon atoms or a substituted or
unsubstituted arylcarbonyloxy group having from 6 to 30, more
preferably from 6 to 20, carbon atoms, e.g., formyloxy, acetyloxy,
pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy)
(16) Carbamoyloxy group (preferably a substituted or unsubstituted
carbamoyloxy group having from 1 to 30, more preferably from 1 to
20, carbon atoms, e.g., N,N-dimethylcarbamoyloxy,
N,N-diethylcarbamoyloxy, morpholinocarbonyloxy,
N,N-di-n-octylaminocarbonyloxy, N-n-octylcarbamoyloxy) (17)
Alkoxycarbonyloxy group (preferably a substituted or unsubstituted
alkoxycarbonyloxy group having from 2 to 30, more preferably from 2
to 20, carbon atoms, e.g., methoxycarbonyloxy, ethoxycarbonyloxy,
tert-butoxycarbonyloxy, n-octylcarbonyloxy) (18) Aryloxycarbonyloxy
group (preferably a substituted or unsubstituted aryloxycarbonyloxy
group having from 7 to 30, more preferably from 7 to 20, carbon
atoms, e.g., phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy,
p-n-hexadecyloxyphenoxycarbonyloxy) (19) Amino group (preferably an
amino group, a substituted or unsubstituted alkylamino group having
from 1 to 30, more preferably from 1 to 20, carbon atoms or a
substituted or unsubstituted anilino group having from 6 to 30
carbon atoms, e.g., amino, methylamino, dimethylamino, anilino,
N-methyl-anilino, diphenylamino) (20) Ammonio group (preferably an
ammonio group or an ammonio group substituted by a substituted or
unsubstituted alkyl, aryl or heterocyclic group having from 1 to
30, more preferably from 1 to 20, carbon atoms, e.g.,
trimethylammonio, triethylammonio, diphenylmethylammonio) (21)
Acylamino group (preferably a formylamino group, a substituted or
unsubstituted alkylcarbonylamino group having from 1 to 30, more
preferably from 1 to 20, carbon atoms or a substituted or
unsubstituted arylcarbonylamino group having from 6 to 30 carbon
atoms, e.g., formylamino, acetylamino, pivaloylamino, lauroylamino,
benzoylamino, 3,4,5-tri-n-octyloxyphenylcarbonylamino) (22)
Aminocarbonylamino group (preferably a substituted or unsubstituted
aminocarbonylamino group having from 1 to 30, more preferably from
1 to 20, carbon atoms, e.g., carbamoylamino,
N,N-dimethylaminocarbonylamino, N,N-diethylaminocarbonylamino,
morpholinocarbonylamino) (23) Alkoxycarbonylamino group (preferably
a substituted or unsubstituted alkoxycarbonylamino group having
from 2 to 30, more preferably from 2 to 20, carbon atoms, e.g.,
methoxycarbonylamino, ethoxycarbonylamino,
tert-butoxycarbonylamino, n-octadecyloxycarbonylamino,
N-methyl-methoxycarbonylamino) (24) Aryloxycarbonylamino group
(preferably a substituted or unsubstituted aryloxycarbonylamino
group having from 7 to 30, more preferably from 7 to 20, carbon
atoms, e.g., phenoxycarbonylamino, p-chlorophenoxycarbonylamino,
m-(n-octyloxy) phenoxycarbonylamino) (25) Sulfamoylamino group
(preferably a substituted or unsubstituted sulfamoylamino group
having from 0 to 30, more preferably from 0 to 20, carbon atoms,
e.g., sulfamoylamino, N,N-dimethylaminosulfonylamino,
N-n-octylaminosulfonylamino) (26) Alkyl- or aryl-sulfonylamino
group (preferably a substituted or unsubstituted alkylsulfonylamino
group having from 1 to 30, more preferably from 1 to 20, carbon
atoms or a substituted or unsubstituted arylsulfonylamino group
having from 6 to 30 carbon atoms, e.g., methylsulfonylamino,
butylsulfonylamino, phenylsulfonylamino,
2,3,5-trichlorophenylsulfonylamino, p-methylphenylsulfonylamino)
(27) Mercapto group (28) Alkylthio group (preferably a substituted
or unsubstituted alkylthio group having from 1 to 30, more
preferably from 1 to 20, carbon atoms, e.g., methylthio, ethylthio,
n-hexadecylthio) (29) Arylthio group (preferably a substituted or
unsubstituted arylthio group having from 6 to 30, more preferably
from 6 to 20, carbon atoms, e.g., phenylthio, p-chlorophenylthio,
m-methoxyphenylthio) (30) Heterocyclic thio group (preferably a
substituted or unsubstituted heterocyclic thio group having from 2
to 30, more preferably from 2 to 20, carbon atoms, e.g.,
2-benzothiazolylthio, 1-phenyltetrazol-5-ylthio) (31) Sulfamoyl
group (preferably a substituted or unsubstituted sulfamoyl group
having from 0 to 30, more preferably from 0 to 20, carbon atoms,
e.g., N-ethylsulfamoyl, N-(3-dodecyloxypropyl)sulfamoyl,
N,N-dimethylsulfamoyl, N-acetylsulfamoyl, N-benzoylsulfamoyl,
N--(N'-phenylcarbamoyl)sulfamoyl) (32) Sulfo group (33) Alkyl- or
aryl-sulfinyl group (preferably a substituted or unsubstituted
alkylsulfinyl group having from 1 to 30, more preferably from 1 to
20, carbon atoms or a substituted or unsubstituted arylsulfinyl
group having from 6 to 30, more preferably from 61 to 20, carbon
atoms, e.g., methylsulfinyl, ethylsulfinyl, phenylsulfinyl,
p-methylphenylsulfinyl) (34) Alkyl- or aryl-sulfonyl group
(preferably a substituted or unsubstituted alkylsulfonyl group
having from 1 to 30, more preferably from 1 to 20, carbon atoms or
a substituted or unsubstituted arylsulfonyl group having from 6 to
30, more preferably from 6 to 20, carbon atoms, e.g.,
methylsulfonyl, ethylsulfonyl, phenylsulfonyl,
p-methylphenylsulfonyl) (35) Acyl group (preferably a formyl group,
a substituted or unsubstituted alkylcarbonyl group having from 2 to
30, more preferably from 2 to 20, carbon atoms, a substituted or
unsubstituted arylcarbonyl group having from 7 to 30, more
preferably from 7 to 20, carbon atoms or a substituted or
unsubstituted heterocyclic carbonyl group having from 4 to 30, more
preferably from 4 to 20, carbon atoms and being bonded to a
carbonyl group through a carbon atom, e.g., acetyl, pivaloyl,
2-chloroacetyl, stearoyl, benzoyl, p-n-octyloxyphenylcarbonyl,
2-pyridylcarbonyl, 2-furylcarbonyl) (36) Aryloxycarbonyl group
(preferably a substituted or unsubstituted aryloxycarbonyl group
having from 7 to 30, more preferably from 7 to 20, carbon atoms,
e.g., phenoxycarbonyl, o-chlorophenoxycarbonyl,
m-nitrophenoxycarbonyl, p-tert-butylphenoxycarbonyl) (37)
Alkoxycarbonyl group (preferably a substituted or unsubstituted
alkoxycarbonyl group having from 2 to 30, more preferably from 2 to
20, carbon atoms, e.g., methoxycarbonyl, ethoxycarbonyl,
tert-butoxycarbonyl, n-octadecyloxycarbonyl) (38) Carbamoyl group
(preferably a substituted or unsubstituted carbamoyl group having
from 1 to 30, more preferably from 1 to 20, carbon atoms, e.g.,
carbamoyl, N-methylcarbamoyl, N,N-dimethylcarbamoyl,
N,N-di-n-octylcarbamoyl, N-(methylsulfonyl)-carbamoyl) (39) Aryl-
or heterocyclic-azo group (preferably a substituted or
unsubstituted arylazo group having from 6 to 30, more preferably
from 6 to 20, carbon atoms or a substituted or unsubstituted
heterocyclic-azo group having from 2 to 30 carbon atoms, e.g.,
phenylazo, p-chlorophenylazo, 5-ethylthio-1,3,4-thiadiazol-2-ylazo)
(40) Imido group (preferably N-succinimido, N-phthalimido) (41)
Phosphino group (preferably a substituted or unsubstituted
phosphino group having from 2 to 30, more preferably from 2 to 20,
carbon atoms, e.g., dimethylphosphino, diphenylphosphino,
methylphenoxyphosphino) (42) Phosphinyl group (preferably a
substituted or unsubstituted phosphinyl group having from 2 to 30,
more preferably from 2 to 20, carbon atoms, e.g., phosphinyl,
dioctyloxyphosphinyl, diethoxyphosphinyl) (43) Phosphinyloxy group
(preferably a substituted or unsubstituted phosphinyloxy group
having from 2 to 30, more preferably from 2 to 20, carbon atoms,
e.g., diphenoxyphosphinyloxy, dioctyloxyphosphinyloxy) (44)
Phosphinylamino group (preferably a substituted or unsubstituted
phosphinylamino group having from 2 to 30, more preferably from 2
to 20, carbon atoms, e.g., dimethoxyphosphinylamino,
dimethylaminophosphinylamino) (45) Phospho group (46) Silyl group
(preferably a substituted or unsubstituted silyl group having from
3 to 30, more preferably from 3 to 20, carbon atoms, e.g.,
trimethylsilyl, triethylsilyl, tri(iso-propyl)silyl,
tert-butyldimethylsilyl, phenyldimethylsilyl) (47) Hydrazino group
(preferably a substituted or unsubstituted hydrazino group having
from 0 to 30, more preferably from 0 to 20, carbon atoms, e.g.,
trimethylhydrazino) (48) Ureido group (preferably a substituted or
unsubstituted ureido group having from 0 to 30, more preferably
from 3 to 20, carbon atoms, e.g., N,N-dimethylureido)
[0027] The two substituents represented by W may also have a
structure condensed with a ring, e.g., an aromatic or non-aromatic
hydrocarbon ring, a heterocyclic ring or a polycyclic condensed
ring formed by the combination of these rings, e.g., a benzene
ring, a naphthalene ring, an anthracene ring, a phenanthrene ring,
fluorene ring, a triphenylene ring, a naphthacene ring, a biphenyl
ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole
ring, an oxazole ring, a thiazole ring, a pyridine ring, a pyrazine
ring, a pyrimidine ring, a pyridazine ring, a indolizine ring, an
indole ring, a benzofuran ring, a benzothiophene ring, an
isobenzofuran ring, a quinolizine ring, a quinoline ring, a
phthalazine ring, a naphthyridine ring, a quinoxaline ring, a
quinoxazoline ring, an isoquinoline ring, a carbazole ring, a
phenanthridine ring, an acridine ring, a phenanthroline ring, a
thianthrene ring, a chromene ring, a xanthene ring, a phenoxathiine
ring, a phenothiazine ring, a phenazine ring. Among these, a
benzene ring, a pyrrole ring, a furan ring, a thiophene ring, an
imidazole ring, an oxazole ring, a thiazole ring, a pyridine ring,
and a pyrazine ring are preferable.
[0028] Among these substituents W, those having a hydrogen atom may
be deprived of the hydrogen atom and substituted by the
above-described substituent. Examples of these substituents include
--CONHSO.sub.2-- group (sulfonylcarbamoyl group, carbonylsulfamoyl
group), --CONHCO-- group (carbonylcarbamoyl group), and
--SO.sub.2NHSO.sub.2-- group (sulfonylsulfamoyl group). Specific
examples thereof include an alkylcarbonylaminosulfonyl group (e.g.,
acetylaminosulfonyl group), an arylcarbonylaminosulfonyl group
(e.g., benzoylaminosulfonyl group), an alkylsulfonylaminocarbonyl
group (e.g., methylsulfonylaminocarbonyl group), and an
arylsulfonylaminocarbonyl group (e.g.,
p-methylphenylsulfonylaminocarbonyl group).
[0029] The compounds represented by formula 1, those in which two
D's are the same are especially preferable.
[0030] Specific examples of the organic photoelectric conversion
material represented by formula 1 of the present invention are
shown in the followings, but the present invention is not limited
thereto. (Et represents an ethyl group and Ph represents a phenyl
group in the following chemical formulae.).
##STR00006## ##STR00007## ##STR00008## ##STR00009## ##STR00010##
##STR00011##
[0031] The above-described exemplified compounds may be synthesized
in accordance with methods described in, for example, Dyes and
Pigments, 1988, 10, p. 12-22, or JP-A No. 2001-117201.
[0032] It is noted that the organic photoelectric conversion
material of the present invention that is represented by formula 1
may be described by formula 1' in which the site of electrons are
shifted from the formula 1. In formula 1', each of D' and D'' has
the same meanings as D in formula 1, except that a plus (+) charge
is present in the structure represented by D''.
##STR00012##
[0033] According to the chemical notation of the formula 1', for
example, the exemplified compound 1 is described below.
##STR00013##
[0034] The organic photoelectric conversion material of the present
invention is easy to form a good quality thin film, and therefore
the material is suitably used for forming a thin film. When a thin
film is formed, it is preferable that the organic photoelectric
conversion material of the present invention is mixed with a binder
material, another organic semiconductor material or the like
whereby they are used as a film containing them. In this
embodiment, the compound represented by the formula 1 is preferably
contained in the film in an amount of equal to or more than 1% by
mass, more preferably equal to or more than 5% by mass, and
furthermore preferably equal to or more than 10% by mass, relative
to the film respectively. The thickness of the photoelectric
conversion layer is not particularly limited, but it is preferably
1 nm to 1 .mu.m, and more preferably 5 nm to 500 nm.
[0035] As a method of forming a thin film containing the organic
photoelectric conversion material of the present invention, there
can be used any of a dry film forming process and a wet film
forming process. The wet film forming process is preferable.
Specific examples of the dry film forming process include a
physical vapor phase growth method such as a vacuum evaporation
method, a spattering method, an ion plating method and a molecular
beam epitaxy (MBE) method, and a chemical vapor deposition (CVD)
method such as a plasma polymerization. As the wet film forming
process (solution-coating method), there is a method of dissolving
an organic photoelectric conversion material in a solvent capable
of dissolving the material or dispersing the material
homogeneously, and making the resultant solution or dispersion a
thin coating to form a film. As specific examples, there can be
used methods such as a cast process, a blade coating process, a
wire bar coating process, a splay coating process, a dip (an
immersion) coating process, a bead coating process, an air knife
coating process, a curtain coating process, an ink jet coating
process, a spin coating process, and a Langmuir-Blodgett (LB)
process. Preferably there can be used a cast process, a spin
coating process and an ink jet coating process. More preferably
there can be used a spin coating process
[0036] In the case of forming an organic photoelectric conversion
layer by the wet film forming process, a coating solution is
prepared by dissolving or dispersing the organic photoelectric
conversion material solely or the material and a binder in an
appropriate organic solvent (e.g., a hydrocarbon solvent, such as
hexane, octane, decane, toluene, xylene, ethylbenzene,
1-methylnaphthalene or 1,2-dichlorobenzene; a ketone solvent, such
as acetone, methyl ethyl ketone, methyl isobutyl ketone or
cyclohexanone; a halogenated hydrocarbon solvent, such as
dichloromethane, chloroform, tetrachloromethane, dichloroethane,
trichloroethane, tetrachloroethane, chlorobenzene, dichlorobenzene
or chlorotoluene; an ester solvent, such as ethyl acetate, butyl
acetate or amyl acetate; an alcohol solvent, such as methanol,
propanol, butanol, pentanol, hexanol, cyclohexanol, methyl
cellosolve, ethyl cellosolve or ethylene glycol; an ether solvent,
such as dibutyl ether, tetrahydrofuran, dioxane or anisole; a polar
solvent, such as N,N-dimethylformamide, N,N-dimethylacetamide,
1-methyl-2-pyrrolidone, 1-methyl-2-imidazolidinone or dimethyl
sulfoxide) and/or water, and the coating solution prepared can be
formed into thin film by various coating methods.
[0037] The solvent is not particularly limited. However, containing
of a high boiling point solvent in the solvent is preferable on
account that volatilization rate slows and also molecular
arrangement order in the film formed by using the solvent becomes
better. It is preferable that a solvent having a high boiling point
of 135.degree. C. or more and less than 300.degree. C. (more
preferably from 135.degree. C. to 210.degree. C.) is contained in a
solvent in an amount of 1% by mass to 100% by mass of the total
solvent. Examples of the high boiling point solvent include ethyl
cellosolve (boiling point (b.p.): 135.degree. C.), n-amyl alcohol
(b.p.:137.degree. C.), xylene (b.p.: 140.degree. C.), amyl acetate
(b.p.: 142.degree. C.), .beta.-picoline (b.p.: 143.degree. C.),
1,1,2,2-tetrachloroethane (b.p.: 146.degree. C.),
N,N-dimethylformamide (b.p.: 153.degree. C.), 1-hexanol (b.p.:
157.degree. C.), o-chlorotoluene (b.p.: 159.degree. C.),
petachloroethane (b.p.: 162.degree. C.), N,N-dimethylacetoamide
(b.p.: 165.degree. C.), o-dichlorobenzene (b.p.: 180.degree. C.),
dimethylsulfoxide (b.p.: 189.degree. C.), ethyleneglycol (b.p.:
198.degree. C.), 1-methyl-2-pyrolidone (b.p.: 202.degree. C.),
nitrobenzene (b.p.: 211.degree. C.), 1,2,4-trichlorobenzene (b.p.:
214.degree. C.), quinoline (b.p.: 238.degree. C.), and
1-chloronaphthalene (b.p.: 260.degree. C.). Among these solvents,
xylene, .beta.-picoline, o-chlorotoluene, or o-dichlorobenzene is
especially preferable. The concentration of the organic
photoelectric conversion material of the present invention in such
a coating solution is adjusted to a range of preferably 0.1 to 80
mass %, more preferably 0.1 to 30 mass %, and further preferably
0.1 to 10 mass %, and thereby the film can be formed with an
arbitrary thickness.
[0038] In the case where a resin binder is used in the present
invention, examples of the resin binder include insulating polymers
such as polystylene, polycarbonate, polyarylate, polyester,
polyamide, polyimide, polyurethane, polysiloxane, polysulfone,
polymethylmethacrylate, polymethylacrylate, cellulose, polyethylene
and polypropylene; and copolymers of these polymers;
photoconductive polymers such as polyvinylcarbazol and polysilane,
and electrically conductive polymers such as polythiophen,
polypyrrole, polyaniline, and polypara phenylenevinilene. The resin
binder may be used solely or, alternatively two or more kinds of
the resin binder may be used in combination. Taking a mechanical
strength of the thin-film into consideration, preferred are resin
binders having a high glass transition temperature. Whereas, taking
a charge transfer degree into consideration, preferred are resin
binders containing no polar group, photoconductive polymers and
electrically conductive polymers. It is preferable in
characteristics not to use such the resin binder. But, the resin
binder is sometimes used according to the purpose. In this case, an
amount of the resin binder used is not particularly limited, but
preferably the binder is used in the range of from 0.1 to 90% by
mass, more preferably in the range of from 0.1 to 50% by mass, and
further preferably in the range of from 0.1 to 30% by mass, based
on the organic photoelectric conversion layer.
[0039] At the time of film formation, the substrate may be heated
or cooled. By changing the substrate temperature, it becomes
possible to control morphology and molecular orientational states
of the film. The substrate temperature, though not particularly
limited, is preferably between 0.degree. C. and 200.degree. C.
[0040] The composition of the organic thin-film photoelectric
conversion device of the present invention is explained in detail
below.
[0041] FIG. 1 is a cross-sectional view schematically showing one
of preferable embodiments of the organic thin-film photoelectric
conversion device of the present invention. The device of FIG. 1
has a multi-layer structure in which a substrate 11 is disposed as
the lowest layer, and an electrode layer 12, a photoelectric
conversion layer 13 containing the photoelectric conversion
material of the present invention, and an electrode layer 14 are
disposed above the substrate in this order. Between the electrode
layer 12, or 14 and the photoelectric conversion layer 13, there
may be disposed additional layers such as a buffer layer capable of
enhancing smoothness of the surface, a carrier injecting layer
capable of accelerating injection of holes or electrons from the
electrode, a carrier transporting layer capable of transporting
holes or electrons, or a carrier block layer capable of blocking
holes or electrons, each of which is not described in FIG. 1. Among
these layers, one layer may be also used as other layers. In the
present invention, these layers that are disposed between the
electrode layer and the photoelectric conversion layer are all
described as a buffer layer irrespective of their functions.
Further, the electrode layer and other layers are not necessarily
flat, but may have a large irregularity, or a three dimensional
shape (for example, comb shape).
[0042] The material for use in the substrate 11 is not particularly
limited, as long as the material transmits a visible light, or an
infrared light. Transmittance of visible light, or infrared light
is preferably equal to or more than 60%, more preferably equal to
or more than 80%, and most preferably equal to or more than 90%.
Examples of the material include polyester films such as
polyethylene naphtalate (PEN), or polyethylene terephthalate (PET),
polyimide films, ceramic, silicon, quartz, and glass. The thickness
of the substrate is not particularly limited.
[0043] As to materials usable for the electrode layer 12, there is
no particular restriction so long as they are pervious to visible
or infrared light and show conductivity. The visible or infrared
transmittance of the material used is preferably at least 60%, far
preferably at least 80%, particularly preferably at least 90%.
Suitable examples of such a material include transparent conductive
oxides, such as ITO, IZO, SnO.sub.2, ATO (antimony-doped tin
oxide), ZnO, AZO (Al-doped zinc oxide), GZO (gallium-doped zinc
oxide), TiO.sub.2 and FTO (fluorine-doped tin oxide). Of these
oxides, ITO and IZO are especially preferred from the viewpoints of
process suitability and smoothness. The thickness is not
particularly limited, but it is preferably 1 nm to 200 nm, and more
preferably 5 nm to 100 nm. When the electrode layer 12 has a
structural independency, the substrate 11 is not necessary. When
the electrode layer 12 is also used as a substrate 11, the film
thickness of the electrode layer may be thicker than that described
above.
[0044] The photoelectric conversion layer 13 contains the organic
photoelectric conversion material of the present invention. The
photoelectric conversion layer may be a single layer consisting of
the organic photoelectric conversion material of the present
invention, or may have a multi-layer structure including a layer
consisting of the organic photoelectric conversion material of the
present invention and one or more other layers containing other
semiconductor materials. The order and the number of the layers in
the multi-layer structure are not particularly limited. Further,
the photoelectric conversion layer may be a layer containing both
the organic photoelectric conversion material of the present
invention and other semiconductor materials. In this embodiment,
both materials may be completely mixed in a molecular level, or may
form any phase-separated structure. The other semiconductor
materials used in these embodiments are preferably n-type
semiconductor materials. It is most preferable to use a layer
containing a blend film composed of the organic photoelectric
conversion material of the present invention and other
semiconductor materials as a photoelectric conversion layer.
[0045] The n-type semiconductor materials may be an organic
semiconductor material, or an inorganic semiconductor material, as
long as the semiconductor material has an electron transportation
property. As the semiconductor materials, fullerene compounds,
phthalocyanine compounds, naphthalene tetracarbonyl compounds,
peryrene tetracarbonyl compounds, or inorganic semiconductor
materials are preferable. Further, fullerene compounds,
phthalocyanine compounds, naphthalene tetracarbonyl compounds, and
peryrene tetracarbonyl compounds are more preferable. Especially,
fullerene compounds are preferable. In the present invention, the
fullerene compound is not particularly limited, as long as the
compound has a fullerene structure in its molecule. Specifically,
as the fullerene compound, any of C.sub.60, C.sub.70, C.sub.76,
C.sub.78, C.sub.80, C.sub.82, C.sub.84, C.sub.86, C.sub.88,
C.sub.90, C.sub.96, C.sub.116, C.sub.180, C.sub.240, C.sub.540, or
the like may be used. Among these compounds, a substituted or
unsubstituted C.sub.60, C.sub.70, or C.sub.86 is preferable. PCBM
([6,6]-phenyl-C.sub.61-butyric acid methyl ester) and analogs
thereof are especially preferable. Examples of the analog include
the same compounds as the PCBM, which have C.sub.70, C.sub.86, or
the like substituted for the portion of C.sub.60; or other aromatic
ring or a hetero ring substituted for the benzene ring substituent;
or n-butyl ester, iso-butyl ester, or the like substituted for the
methyl ester. Similar to the fullerene compound, the phthalocyanine
compound is not particularly limited, as long as the compound has a
phthalocyanine structure in its molecule. Specifically, the
phthalocyanine compound is a substituted or unsubstituted
phthalocyanine and analogs thereof. The phthalocyanine analogs
include not only various kinds of metal phthalocyanine, but also
tetrapyrazinophorpyrazine, naphthalocyanine and anthracyanine As
the phthalocyanine compounds, those having an electron-withdrawing
group are preferable. Further, those substituted with a fluorine
atom (for example, F.sub.16CuCp, and FPc-1) are more preferable.
Further, the naphthalene tetracarbonyl compound is not particularly
limited, as long as the compound has a naphthalene tetracarboxylic
acid structure in its molecule. As the naphthalene tetracarbonyl
compound, naphthalene tetracarboxylic acid anhydride (NTCDA),
naphthalene bisimide compound (NTCDI), and perinone dye (for
example, Pigment Orange 43 (PO43), Pigment Red 194) are preferable.
The peryrene tetracarbonyl compound is not particularly limited, as
long as the compound has a peryrene tetracarboxylic acid structure
in its molecule. As the peryrene tetracarbonyl compound, peryrene
tetracarboxylic acid anhydride (PTCDA), peryrene bisimide compound
(PTCDI), and benzimidazole-condensed peryrene compound (PV) are
preferable. Especially preferable examples of the n-type
semiconductor material are set forth below. Me represents an methyl
group and R represents a hydrogen atom or a substituent (for
example, a linear or branched substituted or unsubstituted alkyl
group, and a substituted or unsubstituted phenyl group) in the
following chemical formulae.
##STR00014## ##STR00015##
[0046] The n-type semiconductor material used in the present
invention is added in an amount of preferably from 0% by mass to
1000% by mass, more preferably from 10% by mass to 500% by mass,
and furthermore preferably from 20% by mass to 200% by mass,
relative to 100% by mass of the compound represented by formula 1.
A content of the compound represented by formula 1 is preferably
from 1% by mass to 100% by mass, more preferably from 10% by mass
to 100% by mass, and furthermore preferably from 20% by mass to
100% by mass in the photoelectric conversion film.
[0047] The material used in the buffer layer may be an organic
material, or an inorganic material, as long as the material has a
carrier transportation property. As the buffer layer material,
amorphous materials are preferable. The buffer material having a
hole transportation property is not particularly limited, but
preferably electrically conductive polymers (for example,
PEDOT:PSS), triarylamine compounds (for example, m-MTDATA), or
inorganic semiconductor materials (for example, NiO) are
preferable. Especially electrically conductive polymers are
preferable. The buffer material having an electron transportation
property is not particularly limited, but preferably not only those
materials described as examples of n-type organic semiconductor
materials, but also metal complex compounds (for example, Alq),
bathocuproin, inorganic fluorides (for example, LiF), inorganic
oxides (for example, SiO.sub.x, TiO.sub.x, ZnO), electrically
conductive polymers (for example, polyparaphenylenevinylene having
a cyano group (CN--PPV), or perinone polymers (BBL). Among these
materials, naphthalene compounds, bathocuproin, inorganic
fluorides, or inorganic oxides are more preferable.
[0048] As to materials usable for the electrode layer 14, there is
no particular restriction so long as they show conductivity. From
the viewpoint of enhancing the light utilization efficiency, highly
reflective materials are preferably used. Of such materials, Al,
Pt, W, Au, Ag, Ta, Cu, Cr, Mo, Ti, Ni, Pd and Zn are especially
preferred; and Al, Pt, Au and Ag are most preferred. The thickness
of the electrode layer 14 is not particularly limited, but it is
preferably 1 nm to 1 .mu.m, and more preferably 5 nm to 500 nm.
[0049] For enhancement of the storage stability of the device, it
is preferable that the device is entirely sealed with a sealing
material under an inactive atmosphere (for example, a nitrogen
atmosphere) so that the device can be held in the inert atmosphere.
Examples of the sealing material include inorganic materials such
as metals, glass, silicon nitride, or alumina, and organic
materials such as parylene. When the device is sealed, an agent
such as a desiccant may be encapsulated.
[0050] The organic thin-layer photoelectric conversion device of
the present invention may be used for energy conversion (thin-layer
organic solar cell), or as an optical sensor (for example,
solid-state image sensor). When used for energy conversion, the
organic thin-layer photoelectric conversion of the present
invention may be used alone, or alternatively may be used with
other organic thin-layer photoelectric conversions in tandem. A
method of using them in tandem is detailed in "Applied Physics
Letters", 2004, 85, p. 5757-5759, which may be used for reference.
The organic thin-layer photoelectric conversion device of the
present invention is excellent in photoelectric conversion
performance particularly in a near infrared range. Therefore, when
the organic thin-layer photoelectric conversion device of the
present invention is used in tandem with a conventional device (for
example, a device using P3HT and PCBM) that is excellent in
photoelectric conversion performance in a visible range,
high-powered solar cells may be obtained.
[0051] When the organic thin-layer photoelectric conversion device
of the present invention is used as an optical sensor, it is
preferable that a bias is applied between the electrodes 12 and 14
to read a signal so that S/N ratio is improved. In this embodiment,
it is preferable that the bias to be applied to a photoelectric
conversion layer is in the range of 1.0.times.10.sup.5 V/cm to
1.0.times.10.sup.7 V/cm. Solid-state image sensors using organic
thin-layer photoelectric conversion devices are detailed in, for
example, JP-A-2003-234460, JP-A-2003-332551, and JP-A-2005-268609,
each of which may be used for reference.
[0052] The present invention will be described in more detail based
on the following examples, but the invention is not intended to be
limited thereto.
[0053] In the following examples, exemplified compounds 1, 5, 9, 16
and 18 were synthesized in accordance with methods described in
"Dyes and Pigments", 1988, 10, p. 12-22, and JP-A-2001-117201. PCBM
was bought from Frontier Carbon Corporation. The comparison
compound P3HT (regioregular, Mw-87000) was bought from Aldrich
Corporation.
EXAMPLES
Example 1
[0054] A glass substrate (2.5 cm.times.2.5 cm) with a patterning of
ITO electrode was washed in isopropyl alcohol using ultrasonic, and
then dried. Thereafter, a UV ozone treatment was performed for 30
minutes in order to remove organic contaminants on the surface of
ITO substrate. Subsequently, an aqueous solution containing PEDOT
(poly (3,4-ethylenedioxythiophene))/PSS (polystyrene sulfonic acid)
(Baytron P standard good) was spin coated on the ITO substrate at
4000 rpm for 60 seconds, and then dried at 120.degree. C. for 10
minutes. Thereby, a 50 nm film-thick buffer layer was formed. The
film thickness was measured using a film thickness meter by a
stylus method (DEKTAK6M (trade name) manufactured by ULVAC, Inc.).
Hereinafter, the same measuring method is applied to the film
thickness. Subsequently, after dissolving 10 mg of the exemplified
compound 1 and 10 mg of PCBM in 1 ml of 1,2-dichlorobenzene (HPLC
grade) in a glove box (nitrogen atmosphere), ultrasonic was
irradiated to the above mixture for 5 minutes, and then the
resultant solution was spin coated at 1000 rpm on the previously
formed buffer layer. Thereby, a 200 nm or less thick photoelectric
conversion layer having an almost uniform thickness was formed. On
the photoelectric conversion layer, aluminum was vacuum-deposited
at degree of vacuum of 2.times.10.sup.-4 Pa or less using a
vacuum-deposition equipment (EBX-8C (trade name), manufactured by
ULVAC, Inc) so that the thickness was 80 nm. Thereby, a metal
electrode was formed. Finally, by sealing with a glass sealing can
and an UV curing resin in a glove box (nitrogen atmosphere), an
organic thin-layer photoelectric conversion device having an
effective area of 0.04 cm.sup.2 was obtained.
[0055] To the thus-obtained device, was irradiated a light in which
a light of a 700 nm or less wavelength range was cut through a
cut-off filter (hereinafter, the light is called "a near infrared
light"), while adjusting the amount of light to AM 1.5, 100
mW/cm.sup.2 using both a solar simulator (150W scaled down type,
manufactured by Oriel Corporation) and an air mass filter.
Thereafter, current-voltage characteristics were measured using an
electrochemical analyzer (ALS model 660B (trade name), manufactured
by BAS Corporation). The results of measurement demonstrated
excellent solar cell characteristics as shown in FIG. 2, namely
short circuit-current (Jsc) of 0.52 mA/cm.sup.2 and open voltage
(Voc) of 0.28 V. From the results, it is understood that the
organic thin-layer photoelectric conversion device using the
exemplified compound 1 has a high sensitivity in a near infrared
range whereby the device functions as a solar cell.
[0056] In the same manner as the above except that a quartz
substrate was used in place of the glass substrate with the
patterning of ITO electrode, a photoelectric conversion film was
spin coated on the PEDOT/PSS film. Then, an absorption spectrum was
measured using an ultraviolet-visual-near infrared
spectrophotometer (UV-3600 (trade name), manufactured by Shimadzu
Corporation). As a result of measurement, a spectrum showing an
absorption exhibiting an absorption maximum wavelength at 837 nm
was obtained as shown in FIG. 3.
Example 2
[0057] Devices manufactured exactly in the same manner as Example 1
except that each of the exemplified compounds 5, 9, 16, and 18 was
used in place of the exemplified compound 1 respectively exhibited
high photoelectric conversion performance equivalent to the device
of Example 1 at the near infrared range. The results of short
circuit-current, open voltage, and absorption .lamda. max of the
photoelectric conversion layer of each of the devices are shown in
Table 1.
Comparison Example 1
[0058] A comparison device was manufactured exactly in the same
manner as Example 1 except that P3HT (poly(3-hexylthiophene)) was
used in place of the exemplified compound 1. The thus-obtained
device was evaluated exactly under the same conditions as Example
1. None of photoelectric conversion performance was exhibited to
the near infrared light as shown in Table 1.
TABLE-US-00001 TABLE 1 Short circuit- Open Absorption Compound
current voltage .lamda..sub.max Remarks Exemplified 0.52
mA/cm.sup.2 0.28 V 837 nm This invention compound 1 Exemplified
0.40 mA/cm.sup.2 0.27 V 820 nm This invention compound 5
Exemplified 0.37 mA/cm.sup.2 0.28 V 881 nm This invention compound
9 Exemplified 0.42 mA/cm.sup.2 0.30 V 943 nm This invention
compound 16 Exemplified 0.33 mA/cm.sup.2 0.26 V 928 nm This
invention compound 18 P3HT 0.00 mA/cm.sup.2 0.00 V 520 nm
Comparative example
[0059] As is apparent from the above Examples and Comparison
Example, it is understood that the organic photoelectric conversion
material of the present invention has a high sensitivity at the
near infrared light range, and the organic thin-layer photoelectric
conversion device of the present invention exhibits a high
photoelectric conversion performance to the near infrared
light.
[0060] Having described our invention as related to the present
embodiments, it is our intention that the invention not be limited
by any of the details of the description, unless otherwise
specified, but rather be construed broadly within its spirit and
scope as set out in the accompanying claims.
* * * * *