U.S. patent application number 17/744916 was filed with the patent office on 2022-09-08 for organic photoelectric conversion element.
The applicant listed for this patent is Sony Corporation, Sony Semiconductor Solutions Corporation. Invention is credited to Osamu ENOKI, Yuta HASEGAWA, Hideaki MOGI, Yuki NEGISHI, Yosuke SAITO, Ichiro TAKEMURA, Yasuharu UJIIE.
Application Number | 20220285630 17/744916 |
Document ID | / |
Family ID | 1000006333157 |
Filed Date | 2022-09-08 |
United States Patent
Application |
20220285630 |
Kind Code |
A1 |
SAITO; Yosuke ; et
al. |
September 8, 2022 |
ORGANIC PHOTOELECTRIC CONVERSION ELEMENT
Abstract
A photoelectric conversion element uses organic materials and is
provided with improved quantum efficiency and response rate. The
organic photoelectric conversion element includes, in a
photoelectric conversion layer, p-type molecules represented by
Formula (1): ##STR00001## in which A represents any one of oxygen,
sulfur or selenium, any one of R.sub.1 to R.sub.4 represents a
substituted or unsubstituted aryl or heteroaryl having 4 to 30
carbon atoms, the remainder of R.sub.1 to R.sub.4 each represent
hydrogen, any one of R.sub.5 to R.sub.8 represents a substituted or
unsubstituted aryl or heteroaryl having 4 to 30 carbon atoms, and
the remainder of R.sub.5 to R.sub.8 each represent hydrogen.
Inventors: |
SAITO; Yosuke; (Tokyo,
JP) ; TAKEMURA; Ichiro; (Kanagawa, JP) ;
ENOKI; Osamu; (Kanagawa, JP) ; NEGISHI; Yuki;
(Kanagawa, JP) ; HASEGAWA; Yuta; (Kanagawa,
JP) ; MOGI; Hideaki; (Kanagawa, JP) ; UJIIE;
Yasuharu; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sony Corporation
Sony Semiconductor Solutions Corporation |
Tokyo
Kanagawa |
|
JP
JP |
|
|
Family ID: |
1000006333157 |
Appl. No.: |
17/744916 |
Filed: |
May 16, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16612139 |
Nov 8, 2019 |
11335861 |
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PCT/JP2018/017595 |
May 7, 2018 |
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17744916 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 27/307 20130101;
H01L 51/4253 20130101; H01L 51/0074 20130101; C07D 495/04 20130101;
H01L 51/0078 20130101; H01L 51/0046 20130101 |
International
Class: |
H01L 51/00 20060101
H01L051/00; C07D 495/04 20060101 C07D495/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 8, 2017 |
JP |
2017-092150 |
Claims
1. An organic photoelectric conversion element comprising: p-type
molecules represented by Formula (1) in a photoelectric conversion
layer: ##STR00057## wherein in the Formula (1), A represents any
one of oxygen, sulfur or selenium, any one of R.sub.1 to R.sub.4
represents a substituted or unsubstituted aryl or heteroaryl having
4 to 30 carbon atoms, the remainder of R.sub.1 to R.sub.4 each
represent hydrogen, any one of R.sub.5 to R.sub.8 represents a
substituted or unsubstituted aryl or heteroaryl having 4 to 30
carbon atoms, and the remainder of R.sub.5 to R.sub.8 each
represent hydrogen.
2. The organic photoelectric conversion element according to claim
1, wherein the photoelectric conversion layer includes, as the
p-type molecules, a compound represented by Formula (15) out of the
compounds represented by Formula (1): ##STR00058##
3. The organic photoelectric conversion element according to claim
2, wherein the photoelectric conversion layer includes, as the
p-type molecules, a compound represented by Formula (16) out of the
compounds represented by Formula (15): ##STR00059## and in the
Formula (16), R.sub.3-1 and R.sub.7-1 are each a substituted or
unsubstituted aryl group or heteroaryl group having 4 to 24 carbon
atoms.
4. The organic photoelectric conversion element according to claim
3, wherein the photoelectric conversion layer includes, as the
p-type molecules, a compound represented by Formula (17) out of the
compounds represented by Formula (16): ##STR00060## and in the
Formula (17), R.sub.3-2 and R.sub.7-2 are each a substituted or
unsubstituted aryl group or heteroaryl group having 4 to 18 carbon
atoms.
5. The organic photoelectric conversion element according to claim
3, wherein the photoelectric conversion layer includes, as the
p-type molecules, a compound represented by Formula (18) out of the
compounds represented by Formula (16): ##STR00061##
6. The organic photoelectric conversion element according to claim
5, wherein the photoelectric conversion layer includes, as the
p-type molecules, a compound represented by Formula (19) out of the
compounds represented by Formula (18): ##STR00062##
Description
TECHNICAL FIELD
[0001] The present technology relates to an organic photoelectric
conversion element, and specifically to an organic photoelectric
conversion element using organic materials.
BACKGROUND ART
[0002] In solid-state imaging devices, photosensor and the like,
photoelectric conversion elements have been used to detect light.
For the enhancement of the sensitivity of these solid-state imaging
devices and photosensors, there is a need to provide photoelectric
conversion elements with improved quantum efficiency. Here, quantum
efficiency means an efficiency of conversion of photons to
electrons. For the enhancement of the operating speed of
solid-state imaging devices and photosensors, on the other hand,
there is a need to provide photoelectric conversion elements with
improved response rate. Now, the term "response rate" means a rate
at which the value of a light current measured under illumination
of light falls after stopping the illumination of light. For
improved quantum efficiency, two methods are effective, one being
to provide an element with a bulk-heterostructure, and the other to
increase the carrier mobility. For improved response rate, on the
other hand, an effective method is to increase the carrier
mobility. For example, photoelectric conversion films of a
bulk-heterostructure with two kinds of organic materials mixed
together have been proposed (for example, see PTL 1).
CITATION LIST
Patent Literature
[0003] [PTL 1] [0004] Japanese Patent Laid-Open No. 2002-076391
SUMMARY
Technical Problem
[0005] With the above-described conventional technology, however, a
photoelectric conversion film cannot be provided with a
sufficiently increased carrier mobility because the
bulk-heterostructure is inhibited from crystallization and is
subjected to amorphization or solution treatment. As a consequence,
there is a problem in that the quantum efficiency and response rate
can be hardly improved.
[0006] The present technology has emerged in view of such
circumstances as described above, and has as an object thereof to
provide improvements in the quantum efficiency and response rate of
a photoelectric conversion element that uses organic materials.
Solution to Problem
[0007] The present technology has been made to resolve the
above-described problem, and in a first aspect thereof provides an
organic photoelectric conversion element including p-type molecules
represented by Formula (1) in a photoelectric conversion layer:
##STR00002##
in which A represents any one of oxygen, sulfur or selenium, any
one of R.sub.1 to R.sub.4 represents a substituted or unsubstituted
aryl or heteroaryl having 4 to 30 carbon atoms, the remainder of
R.sub.1 to R.sub.4 each represent hydrogen, any one of R.sub.5 to
R.sub.8 represents a substituted or unsubstituted aryl or
heteroaryl having 4 to 30 carbon atoms, and the remainder of
R.sub.5 to R.sub.8 each represent hydrogen. This configuration
brings about effects of improvements in the quantum efficiency and
response rate of the organic photoelectric conversion element.
[0008] In the first aspect, the photoelectric conversion layer may
further include n-type molecules, and the n-type molecules may
include a fullerene or a fullerene derivative. Owing to this
configuration, a bulk heterostructure is formed, thereby bringing
about effects of improvements in the quantum efficiency and
response rate of the organic photoelectric conversion element.
[0009] Further, in the first aspect, the n-type molecules amount to
a volume fraction of 10 to 50 percent relative to the photoelectric
conversion layer. Owing to this configuration, a bulk
heterostructure is formed, thereby bringing about effects of
improvements in the quantum efficiency and response rate of the
organic photoelectric conversion element.
[0010] Further, in the first aspect, the n-type molecules may
include the fullerene derivative represented by any one of Formula
(2) or (3):
##STR00003## ##STR00004##
and in the Formulae (2) and (3), R independently represents
hydrogen, halogen, linear, branched or cyclic alkyl, phenyl, a
linear or fused-ring aromatic-containing group, a
halogenide-containing group, partial fluoroalkyl, perfluoroalkyl,
silylalkyl, silylalkoxy, arylsilyl, arylsulfanyl, alkylsulfanyl,
arylsulfonyl, alkylsulfonyl, arylsulfido, alkylsulfido, amino,
alkylamino, arylamino, hydroxy, alkoxy, acylamino, acyloxy,
carbonyl, carboxy, carboxamido, carboalkoxy, acyl, sulfonyl, cyano,
nitro, a chalcogenide-containing group, phosphino or phosphono, or
a derivative thereof, and n and m each stand for an integer. Owing
to this configuration, a bulk heterostructure is formed, thereby
bringing about effects of improvements in the quantum efficiency
and response rate of the organic photoelectric conversion
element.
[0011] In the first aspect, the photoelectric conversion layer may
further include a colorant, and the colorant may have a maximum
absorption coefficient of not smaller than 50000 cm.sup.-1 in a
wavelength range of visible light. This configuration brings about
an effect of an improvement in the sensitivity of the organic
photoelectric conversion element to visible light.
[0012] Further, in the first aspect, the colorant may amount to a
volume fraction of 20 to 80 percent relative to the photoelectric
conversion layer. This configuration brings about an effect of an
improvement in the sensitivity of the organic photoelectric
conversion element to visible light.
[0013] Further, in the first aspect, the colorant may include a
subphthalocyanine derivative. This configuration brings about an
effect of an improvement in the sensitivity of the organic
photoelectric conversion element to visible light.
[0014] Further, in the first aspect, the colorant may include a
subphthalocyanine derivative represented by Formula (4):
##STR00005##
and R.sub.9 to R.sub.20 in the Formula (4) are each independently
selected from a group including hydrogen, halogen, linear, branched
or cyclic alkyl, thioalkyl, thioaryl, arylsulfonyl, alkylsulfonyl,
amino, alkylamino, arylamino, hydroxy, alkoxy, acylamino, acyloxy,
phenyl, carboxy, carboxamido, carboalkoxy, acyl, sulfonyl, cyano
and nitro, M represents boron or a divalent or trivalent metal, and
X represents an anionic group. This configuration brings about an
effect of an improvement in the sensitivity of the organic
photoelectric conversion element to visible light.
[0015] Further, in the first aspect, the p-type molecules may
amount to a volume fraction of 10 to 70 percent relative to the
photoelectric conversion layer. This configuration brings about
effects of improvements in the quantum efficiency and response rate
of the organic photoelectric conversion element.
[0016] Further, in the first aspect, the photoelectric conversion
layer may include, as the p-type molecules, a compound represented
by Formula (9) out of the compounds represented by Formula (1).
This configuration brings about effects of improvements in the
quantum efficiency and response rate of the organic photoelectric
conversion element.
##STR00006##
[0017] Further, in the first aspect, the photoelectric conversion
layer may include, as the p-type molecules, a compound represented
by Formula (10) out of the compounds represented by Formula
(9):
##STR00007##
and in the Formula (10), R.sub.2-1 and R.sub.6-1 may each be a
substituted or unsubstituted aryl group or heteroaryl group having
4 to 24 carbon atoms. This configuration brings about effects of
improvements in the quantum efficiency and response rate of the
organic photoelectric conversion element.
[0018] Further, in the first aspect, the photoelectric conversion
layer includes, as the p-type molecules, a compound represented by
Formula (11) out of the compounds represented by Formula (10):
##STR00008##
and in the Formula (11), R.sub.2-2 and R.sub.6-2 may each be a
substituted or unsubstituted aryl group or heteroaryl group having
4 to 18 carbon atoms. This configuration brings about effects of
improvements in the quantum efficiency and response rate of the
organic photoelectric conversion element.
[0019] Further, in the first aspect, the photoelectric conversion
layer may include, as the p-type molecules, a compound represented
by Formula (12) out of the compounds represented by Formula (10).
This configuration brings about effects of improvements in the
quantum efficiency and response rate of the organic photoelectric
conversion element.
##STR00009##
[0020] Further, in the first aspect, the photoelectric conversion
layer may include, as the p-type molecules, a compound represented
by Formula (13) out of the compounds represented by Formula (12).
This configuration brings about effects of improvements in the
quantum efficiency and response rate of the organic photoelectric
conversion element.
##STR00010##
[0021] Further, in the first aspect, the photoelectric conversion
layer may include, as the p-type molecules, a compound represented
by Formula (15) out of the compounds represented by Formula (1).
This configuration brings about effects of improvements in the
quantum efficiency and response rate of the organic photoelectric
conversion element.
##STR00011##
[0022] Further, in the first aspect, the photoelectric conversion
layer may include, as the p-type molecules, a compound represented
by Formula (16) out of the compounds represented by Formula
(15):
##STR00012##
and in the Formula (16), R.sub.3-1 and R.sub.7-1 may each be a
substituted or unsubstituted aryl group or heteroaryl group having
4 to 24 carbon atoms. This configuration brings about effects of
improvements in the quantum efficiency and response rate of the
organic photoelectric conversion element.
[0023] Further, in the first aspect, the photoelectric conversion
layer may include, as the p-type molecules, a compound represented
by Formula (17) out of the compounds represented by Formula
(16):
##STR00013##
and in the Formula (17), R.sub.3-2 and R.sub.7-2 may each be a
substituted or unsubstituted aryl group or heteroaryl group having
4 to 18 carbon atoms. This configuration brings about effects of
improvements in the quantum efficiency and response rate of the
organic photoelectric conversion element.
[0024] Further, in the first aspect, the photoelectric conversion
layer may include, as the p-type molecules, a compound represented
by Formula (18) out of the compounds represented by Formula (16).
This configuration brings about effects of improvements in the
quantum efficiency and response rate of the organic photoelectric
conversion element.
##STR00014##
[0025] Further, in the first aspect, the photoelectric conversion
layer may include, as the p-type molecules, a compound represented
by Formula (19) out of the compounds represented by Formula (18).
This configuration brings about effects of improvements in the
quantum efficiency and response rate of the organic photoelectric
conversion element.
##STR00015##
[0026] Further, the present technology also provides, in a second
aspect thereof, an organic photoelectric conversion element
including p-type molecules represented by Formula (20) in a
photoelectric conversion layer:
##STR00016##
[0027] in which A represents any one of oxygen, sulfur or selenium,
any one of R.sub.21 to R.sub.25 represents a substituted or
unsubstituted aryl or heteroaryl having 4 to 30 carbon atoms, the
remainder of R.sub.21 to R.sub.25 each represent hydrogen, any one
of R.sub.26 to R.sub.30 represents a substituted or unsubstituted
aryl or heteroaryl having 4 to 30 carbon atoms, and the remainder
of R.sub.26 to R.sub.30 each represent hydrogen. This configuration
brings about effects of improvements in the quantum efficiency and
response rate of the organic photoelectric conversion element.
[0028] In the second aspect, the photoelectric conversion layer may
further include n-type molecules, and the n-type molecules may
include a fullerene or a fullerene derivative. Owing to this
configuration, a bulk heterostructure is formed, thereby bringing
about effects of improvements in the quantum efficiency and
response rate of the organic photoelectric conversion element.
[0029] Further, in the second aspect, the n-type molecules may
amount to a volume fraction of 10 to 50 percent relative to the
photoelectric conversion layer. Owing to this configuration, a bulk
heterostructure is formed, thereby bringing about effects of
improvements in the quantum efficiency and response rate of the
organic photoelectric conversion element.
[0030] Further, in the second aspect, the n-type molecules may
include the fullerene derivative represented by any one of Formula
(2) or (3):
##STR00017## ##STR00018##
and in the Formulae (2) and (3), R independently represents
hydrogen, halogen, linear, branched or cyclic alkyl, phenyl, a
linear or fused-ring aromatic-containing group, a
halogenide-containing group, partial fluoroalkyl, perfluoroalkyl,
silylalkyl, silylalkoxy, arylsilyl, arylsulfanyl, alkylsulfanyl,
arylsulfonyl, alkylsulfonyl, arylsulfido, alkylsulfido, amino,
alkylamino, arylamino, hydroxy, alkoxy, acylamino, acyloxy,
carbonyl, carboxy, carboxamido, carboalkoxy, acyl, sulfonyl, cyano,
nitro, a chalcogenide-containing group, phosphino or phosphono, or
a derivative thereof, and n and m each stand for an integer. Owing
to this configuration, a bulk heterostructure is formed, thereby
bringing about effects of improvements in the quantum efficiency
and response rate of the organic photoelectric conversion
element.
[0031] In the second aspect, the photoelectric conversion layer may
further include a colorant, and the colorant may have a maximum
absorption coefficient of not smaller than 50000 cm.sup.-1 in a
wavelength range of visible light. This configuration brings about
an effect of an improvement in the sensitivity of the organic
photoelectric conversion element to visible light.
[0032] Further, in the second aspect, the colorant may amount to a
volume fraction of 20 to 80 percent relative to the photoelectric
conversion layer. This configuration brings about an effect of an
improvement in the sensitivity of the organic photoelectric
conversion element to visible light.
[0033] Further, in the second aspect, the colorant may include a
subphthalocyanine derivative. This configuration brings about an
effect of an improvement in the sensitivity of the organic
photoelectric conversion element to visible light.
[0034] Further, in the second aspect, the colorant may include a
subphthalocyanine derivative represented by Formula (4):
##STR00019##
and R.sub.9 to R.sub.20 in the Formula (4) may each be
independently selected from a group including hydrogen, halogen,
linear, branched or cyclic alkyl, thioalkyl, thioaryl,
arylsulfonyl, alkylsulfonyl, amino, alkylamino, arylamino, hydroxy,
alkoxy, acylamino, acyloxy, phenyl, carboxy, carboxamido,
carboalkoxy, acyl, sulfonyl, cyano and nitro, M represents boron or
a divalent or trivalent metal, and X represents an anionic group.
This configuration brings about an effect of an improvement in the
sensitivity of the organic photoelectric conversion element to
visible light.
[0035] In the second aspect, the p-type molecules may amount to a
volume fraction of 10 to 70 percent relative to the photoelectric
conversion layer. This configuration brings about effects of
improvements in the quantum efficiency and response rate of the
organic photoelectric conversion element.
Advantageous Effect of Invention
[0036] According to this technology, it is possible to bring about
excellent advantageous effects of improvements in the quantum
efficiency and response rate of a photoelectric conversion element
that uses organic materials. It is to be noted that advantageous
effects described here may not be necessarily limited but any one
of advantageous effects described in the present disclosure.
BRIEF DESCRIPTION OF DRAWINGS
[0037] FIG. 1 is a block diagram illustrating a configuration
example of a solid-state imaging device in a first embodiment of
the present technology.
[0038] FIG. 2 is a circuit diagram illustrating a configuration
example of a pixel in the first embodiment of the present
technology.
[0039] FIG. 3 is a diagram illustrating a configuration example of
an organic photoelectric conversion element in the first embodiment
of the present technology.
[0040] FIG. 4 is a diagram illustrating a configuration example of
a hole mobility evaluation element in the first embodiment of the
present technology.
[0041] FIG. 5 is a graph illustrating an example of results of
X-ray diffractometry of a monolayer film of p-type molecules in
Example 1 of the first embodiment of the present technology.
[0042] FIG. 6 is a graph illustrating an example of results of
X-ray diffractometry of a photoelectric conversion layer in Example
1 of the first embodiment of the present technology.
[0043] FIG. 7 is a graph illustrating an example of results of
X-ray diffractometry of a monolayer film of p-type molecules in
Example 2 of the first embodiment of the present technology.
[0044] FIG. 8 is a graph illustrating an example of results of
X-ray diffractometry of a photoelectric conversion layer in Example
2 of the first embodiment of the present technology.
[0045] FIG. 9 is a graph illustrating an example of X-ray
diffraction results of a monolayer film of p-type molecules in a
second embodiment of the present technology.
[0046] FIG. 10 is a graph illustrating an example of results of
X-ray diffractometry of a photoelectric conversion layer in the
second embodiment of the present technology.
DESCRIPTION OF EMBODIMENTS
[0047] Modes for practicing the present technology (hereinafter
called "embodiments") will hereinafter be described. The
description will be made in the following order. [0048] 1. First
embodiment (an example in which p-type molecules represented by
Formula (1) are included in a photoelectric conversion layer)
[0049] 2. Second embodiment (an example in which p-type molecules
represented by Formula (9) are included in a photoelectric
conversion layer)
1. First Embodiment
Configuration Example of Solid-state Imaging Device
[0050] FIG. 1 is a block diagram illustrating a configuration
example of a solid-state imaging device 200 in the first embodiment
of the present technology. This solid-state imaging device 200 is
arranged in an electronic device (personal computer, smartphone,
digital camera, or the like) having an imaging function. The
solid-state imaging device 200 includes a row scanning circuit 210,
a pixel array section 220, a DAC (Digital to Analog Converter) 250,
a signal processing section 260, a timing control section 270, and
a column scanning circuit 280.
[0051] Further, in the pixel array section 220, a plurality of
pixels 230 is arranged in a two-dimensional lattice pattern.
[0052] The row scanning circuit 210 drives the pixels 230 to output
pixel signals. The timing control section 270 controls timings at
which the row scanning circuit 210, signal processing section 260
and column scanning circuit 280 operate, respectively. The DAC 250
generates ramp signals by DA (digital-to-analog) conversion, and
supplies them to the signal processing section 260.
[0053] The signal processing section 260 performs signal processing
such as AD (analog-to-digital) conversion on pixel signals to
generate pixel data. The column scanning circuit 280 controls the
signal processing section 260 to output pixel data.
[0054] [Configuration Example of Pixel]
[0055] FIG. 2 is a circuit diagram illustrating a configuration
example of the pixel 230 in the first embodiment of the present
technology. The pixel 230 includes an organic photoelectric
conversion element 240, a transfer transistor 231, a floating
diffusion layer 232, an amplifier transistor 233, and a selection
transistor 234.
[0056] The organic photoelectric conversion element 240
photoelectrically converts incident light to generate electric
charges. The transfer transistor 231 acts to transfer the electric
charges from the organic photoelectric conversion element 240 to
the floating diffusion layer 232 according to transfer signals from
the row scanning circuit 210.
[0057] The floating diffusion layer 232 acts to accumulate electric
charges, and to generates voltages according to the quantities of
the electric charges so accumulated. The amplifier transistor 233
acts to amplify the voltages from the floating diffusion layer 232,
and to generate analog pixel signals. The selection transistor 234
acts to output pixel signals to the signal processing section 260
according to selection signals from the row scanning circuit
210.
[0058] It is to be noted that the organic photoelectric conversion
element 240 is arranged in the solid-state imaging device 200 but
may also be arranged in a circuit or device other than the
solid-state imaging device 200. For example, the organic
photoelectric conversion element 240 can also be arranged in a ToF
(time-of-flight) sensor or in a line sensor that detects phase
differences.
Configuration Example of Organic Photoelectric Conversion
Element
[0059] FIG. 3 is a diagram illustrating a configuration example of
the organic photoelectric conversion element 240 in the first
embodiment of the present technology. This organic photoelectric
conversion element 240 includes an upper electrode 241, a charge
transport layer 242, a photoelectric conversion layer 243, a lower
electrode 244, and a substrate 245.
[0060] As the material of the substrate 245, quartz glass is used,
for example. Taking, as an upward direction, the direction from the
substrate 245 to the upper electrode 241, the lower electrode 244
is formed over the substrate 245. As the material of the lower
electrode 244, indium tin oxide (ITO) is used, for example.
[0061] Over the lower electrode 244, the photoelectric conversion
layer 243 is formed. This photoelectric conversion layer 243
includes p-type molecules represented by Formula (1), n-type
molecules, and a colorant.
##STR00020##
[0062] in which A represents any one of oxygen (O), sulfur (S) or
selenium (Se), any one of R.sub.1 to R.sub.4 represents a
substituted or unsubstituted aryl or heteroaryl having 4 to 30
carbon atoms, the remainder of R.sub.1 to R.sub.4 each represent
hydrogen (H), any one of R.sub.5 to R.sub.8 represents a
substituted or unsubstituted aryl or heteroaryl having 4 to 30
carbon atoms, and the remainder of R.sub.5 to R.sub.8 each
represent hydrogen (H).
[0063] Here, the term "substituted or unsubstituted" means that a
compound may have one or more of various desired substituents in
place of a like number of hydrogen atoms in the compound or may
have none of such substituents.
[0064] Further, as the positions of substitution by aryl groups or
heteroaryl groups in Formula (1), the combination of R.sub.2 and
R.sub.6 or the combination of R.sub.3 and R.sub.7 is desired for
the reason that a linear, fused-ring molecule of high planarity
like Formula (1) is known to have a herringbone crystal structure
and to form a two-dimensional carrier transport path and the
molecular shape is desirably linear in order to have such a crystal
structure. The selection of aryl groups or heteroaryl groups for
either R.sub.2 and R.sub.6 or R.sub.3 and R.sub.7 allows the
positions of substitution to be linear.
[0065] For a similar reason, even if each aryl group is not single
but is connected to a biphenyl group or a terphenyl group, each
ring of the aryl group is desirably connected at the para position
thereof to the biphenyl or terphenyl group from the viewpoint of
providing linearity. If a five-membered ring such as a bithienyl
group or terthienyl group is connected to an aryl group or a
heteroaryl group, the connection via the carbon at the alpha
position of the thiophene ring is desired for higher linearity.
Further, if each aryl group or each heteroaryl group includes a
fused multi-ring group such as naphthalene ring, benzothiophene
ring or indole ring, they are desirably connected to provide high
linearity.
[0066] The substituents of R.sub.1 to R.sub.4 and of R.sub.5 to
R.sub.8 are desirably the same, and in addition the symmetry of the
positions of substitution is desirably twofold symmetry, for the
reason that, in a case of having a crystal structure, higher
symmetry leads to smaller anisotropy and to a smaller band
dispersion width.
[0067] Now, for the realization of high quantum efficiency and
response rate in an organic photoelectric conversion element, it is
effective to have a bulk-heterostructure and also to increase the
carrier mobilities of respective organic materials. The term
"bulk-heterostructure" means that an electron-donating, organic
semiconductor material and an electron-accepting, organic
semiconductor material are separated in different phases on a
nanometer scale. Owing to such a bulk-heterostructure, it is
possible to shorten the distance over which excitons generated
under illumination of light move to a donor/acceptor interface, so
that the dissociation efficiency of excitons into holes and
electrons is increased. Further, this improved carrier mobility can
increase the efficiency that the resulting holes and electrons
reach respective electrodes without recombination. For an increase
in this carrier mobility, the organic semiconductor is desirably
crystalline, because a regular structure leads to a greater overlap
between adjacent molecular orbitals and hence to a higher
probability of hopping and a higher carrier transfer rate. For the
realization of an organic photoelectric conversion element having
high quantum efficiency and response rate, there is a need for
materials that exhibit a high carrier mobility for crystallization
while undergoing phase separation on a nanometer scale owing to its
bulk-heterostructure. The compound of Formula 1 is a p-type
material that satisfies these conditions.
[0068] On the other hand, the n-type molecules include, for
example, at least one fullerene or fullerene derivative. As the
fullerene derivative, a compound represented by Formula (2) or
formula (3) is used, for example:
##STR00021##
in which R independently represents hydrogen, halogen, linear,
branched or cyclic alkyl, phenyl, a linear or fused-ring
aromatic-containing group, a halogenide-containing group, partial
fluoroalkyl, perfluoroalkyl, silylalkyl, silylalkoxy, arylsilyl,
arylsulfanyl, alkylsulfanyl, arylsulfonyl, alkylsulfonyl,
arylsulfido, alkylsulfido, amino, alkylamino, arylamino, hydroxy,
alkoxy, acylamino, acyloxy, carbonyl, carboxy, carboxamido,
carboalkoxy, acyl, sulfonyl, cyano, nitro, a
chalcogenide-containing group, phosphino or phosphono, or a
derivative thereof, and n and m each stand for an integer.
[0069] Further, the colorant has a maximum absorption coefficient
of not smaller than 50000 cm.sup.-1 in a wavelength range of
visible light (for example, 400 to 750 nm). As this colorant, a
subphthalocyanine derivative represented by Formula (4) is used,
for example:
##STR00022##
in which R.sub.9 to R.sub.20 are each independently selected from
the group including hydrogen, halogen, linear, branched or cyclic
alkyl, thioalkyl, thioaryl, arylsulfonyl, alkylsulfonyl, amino,
alkylamino, arylamino, hydroxy, alkoxy, acylamino, acyloxy, phenyl,
carboxy, carboxamido, carboalkoxy, acyl, sulfonyl, cyano and nitro,
M represents boron or a divalent or trivalent metal, and X
represents an anionic group. Examples of this anionic group include
halogen, cyano, alkoxy (including alkoxy groups in alkyl compounds,
polycyclic aromatic hydrocarbons, and heteroring-containing
compounds), and phenoxy.
[0070] It is to be noted that in Formula (4), desired adjacent ones
of R.sub.9 to R.sub.20 may each be a moiety of a fused aliphatic
ring or fused aromatic ring. Further, the fused aliphatic ring or
fused aromatic ring may contain one or a plurality of non-carbon
atoms.
[0071] Furthermore, the p-type molecules amount to a volume
proportion, that is, a volume fraction of 10 to 70 percent (%)
relative to the photoelectric conversion layer 243. On the other
hand, the colorant amounts to a volume fraction of 20 to 80 percent
(%) relative to the photoelectric conversion layer 243, and the
n-type molecules amount to a volume fraction of 10 to 50 percent
relative to the photoelectric conversion layer 243. The proportions
of the p-type molecules, colorant and n-type molecules are set, for
example, at 3:3:2 so that these conditions are satisfied.
[0072] Over the photoelectric conversion layer 243, the charge
transport layer 242 is formed. As the material of the charge
transport layer 242,
bis-3,6-(3,5-di-4-pyridylphenyl)-2-methylpyrimidine (hereinafter
abbreviated as "B4PyMPM") is used, for example.
[0073] Over the charge transport layer 242, the upper electrode 241
is formed. As the material of the upper electrode 241, an electrode
material, for example, a transparent conductive metal oxide
semiconductor of indium tin oxide (ITO) or indium zinc oxide (IZO)
is desired. As an alternative, a metal electrode of Al, an
Al--Si--Cu alloy, Cu, Ag or Au may also be used.
[Fabrication Method of Organic Photoelectric Conversion
Element]
[0074] A simplistic description will next be made about a
fabrication method of the organic photoelectric conversion element
240. First, the substrate 245 with the lower electrode 244 formed
thereover was cleaned by ultraviolet (UV)/ozone treatment, and the
substrate 245 was transferred into a vacuum deposition machine.
With the pressure reduced to 1.times.10.sup.-5 Pascal (Pa) inside
the vacuum deposition machine, the photoelectric conversion layer
243 that included the p-type molecules of Formula (1), the colorant
of Formula (4) and the n-type molecules (fullerene or the like) was
deposited to 200 nanometer (nm) while rotating a substrate holder.
The deposition rates of the p-type molecules, colorant and n-type
molecules are, for example, 0.75 angstrom/sec, 0.75 angstrom/sec
and 0.50 angstrom/sec, respectively.
[0075] Subsequently, B4PyMPM was deposited to 5 nanometer (nm) at a
deposition rate of 0.3 angstrom/sec to form the charge transport
layer 242. Finally, an Al--Si--Cu alloy was vapor deposited with a
thickness of 100 nanometer to form the upper electrode 241. By
those procedures, the organic photoelectric conversion element 240
was fabricated with a light-receiving area of 1 millimeter (mm)
square.
Example 1
[0076] A description will next be made about Example 1 in the first
embodiment. In Example 1, p-type molecules were prepared according
to the following reaction scheme:
##STR00023##
[0077] In Scheme (5), the synthesis of the compound (b) was
conducted with reference to Paragraph [0145] in the specification
of US Patent Application Publication No. 2013/0228752. Described
specifically, under an argon (Ar) atmosphere in a four-necked
flask, 5-bromo-2-fluoroaniline, 4-biphenylboronic acid, potassium
carbonate and Pd(PPh.sub.3).sub.4 were refluxed with heating in a
mixed solution of distilled water and toluene. Here, the chemical
equivalents of 5-bromo-2-fluoroaniline, 4-biphenylboronic acid,
potassium carbonate and Pd(PPh.sub.3).sub.4 were "1," "1," "2.6"
and "0.0180," respectively. After allowed to cool at room
temperature, the precipitated solid was collected by filtration,
dissolved in chloroform, and collected by filtration on silica gel.
As a result, the compound (b) was obtained as a white solid with a
yield of approximately 62 percent (%).
[0078] The synthesis of the compound (c) was next conducted with
reference to Scheme (4) of Qiu D., et al., "Synthesis of pinacol
arylboronates from aromatic amines: a metal-free transformation,"
J. Org. Chem., 2013, 78, 1923-1933. Described specifically, under
an argon (Ar) atmosphere in a Schlenk flask, the compound (b),
bis(pinacolato)diboron and tert-butyl nitrite were stirred at
80.degree. C. over 2 hours in acetonitrile. Here, the chemical
equivalents of the compound (b), bis(pinacolato)diboron and
tert-butyl nitrite were "1," "1.2" and "2.4," respectively. After
allowed to cool at room temperature, the precipitated solid was
collected by filtration, the resulting solid was dissolved in
dichloromethane, the resulting solution was filtered through silica
gel, and the filtrate was concentrated. As a result, the compound
(c) was obtained as a creamy yellow solid with a yield of
approximately 40 percent (%).
[0079] The synthesis of the compound (e) was next conducted with
reference to Scheme 3 in Toyoshi Shimada, et al., "Nickel-Catalyzed
Asymmetric Grignard Cross-Coupling of Dinaphthothiophene Giving
Axially Chiral 1,1'-Binaphthyls," J. Org. Chem. J. Am. Chem. Soc.,
2002, 124, 13396-13397. Described specifically, under an argon (Ar)
atmosphere in a 4-necked flask, 1,5-dimethylcaptonaphthalene,
potassium carbonate and methyl iodide were stirred overnight at
room temperature in acetone. Here, the chemical equivalents of
1,5-dimethylcaptonaphthalene, potassium carbonate and methyl iodide
were "1," "6" and "2," respectively. Distilled water (500
milliliter (mL)) was then added to the reaction suspension, and the
precipitated solid was collected by filtration, followed by
purification. As a result, the compound (e) was obtained as a pale
yellow solid with a yield of approximately 79%.
[0080] Through a bromination reaction, the compound (0 was then
synthesized from the compound (e). Further, the compound (g) was
synthesized from the compound (0 through the Suzuki-Miyaura
coupling reaction, followed by the synthesis of the compound (h)
from the compound (g) through a cyclization reaction. The compound
(h) was used as p-type molecules. The compound (h) in Scheme (5)
was an example of the compound of Formula (1).
[0081] Further, "NANOM PURPLE SUH" (product of Frontier Carbon
Corporation) was used as n-type molecules of fullerene in Example
1. The fullerene was a product purified by sublimation, and had an
HPLC (High Performance Liquid Chromatography) purity of higher than
99.9 percent (%).
[0082] Furthermore, the colorant was synthesized through the
following reaction scheme with reference to Paragraphs [0084] to
[0088] in Japan Patent Application No. 2014-099816 (Japan Patent
Laid-open No. 2015-233117), and the resulting compound was
subjected to purification by sublimation.
##STR00024##
[0083] In addition, as B4PyMPM, the compound represented by the
following formula was used.
##STR00025##
Comparative Example 1
[0084] A description will next be made about Comparative Example 1
in the first embodiment. In Comparative Example 1, a quinacridone
derivative, specifically, butyl quinacridone (hereinafter,
abbreviated as "BQD") represented by Formula (8) was used as p-type
molecules.
##STR00026##
[0085] In Comparative Example 1, the production processes of the
parts other than the p-type molecules were similar those in Example
1.
[Characteristics of Photoelectric Conversion Element]
[0086] A description will next be made about evaluation methods for
characteristics of the organic photoelectric conversion element
according to Example 1 and those of the organic photoelectric
conversion element according to Comparative Example 1. The
photoelectric conversion elements or photoelectric conversion
layers in Example 1 and Comparative Example 1 were each evaluated
for external quantum efficiency, dark current, response rate,
crystallinity and hole mobility. In addition, monolayer films of
the p-type materials used in Example 1 and Comparative Example 1
were evaluated for crystallinity and hole mobility.
[0087] The evaluation of dark current was conducted as will be
described next. In a dark state, a bias voltage to be applied
between the electrodes of each organic photoelectric conversion
element was controlled using a semiconductor parameter analyzer.
Setting the voltage of the upper electrode at "-2.6" volt (V)
relative to that of the lower electrode, a dark current value was
measured.
[0088] In the evaluation of external quantum efficiency, light was
illuminated to each organic photoelectric conversion element from a
light source through a filter. The wavelength of the light was 565
nanometer (nm), and the quantity of the light was 1.62 microwatt
per centimeter (.mu.W/cm.sup.2). On the other hand, a bias voltage
to be applied between the electrodes of the organic photoelectric
conversion element was controlled using a semiconductor parameter
analyzer. The voltage of the upper electrode was "-2.6" volt (V)
relative to that of the lower electrode. Under those conditions,
measurements were made for the value of light current and the value
of dark current. From the difference between the value of light
current and the value of dark current and the quantity of received
light, the external quantum efficiency was calculated.
[0089] In the evaluation of response rate, a measurement was made
for a rate at which the value of a light current measured by a
semiconductor parameter analyzer during illumination of light fell
after stopping the illumination of light. Described specifically,
the quantity of light to be illuminated to each photoelectric
conversion element from a light source through a filter was set at
1.62 .mu.W/cm.sup.2, and the bias voltage to be applied between the
electrodes was set at -2.6 V. After a measurement was made for
steady-state current in the above-described state, the rate at
which the current progressively decayed after stopping the
illumination of light was set as an indicator for response
characteristics. Comparisons will hereinafter be made in terms of
standardized response rate with the response rate in Example 1
being assumed to be 1.
[0090] The evaluation of crystallinity was made on the monolayer
films of the p-type materials used in Example 1 and Comparative
Example 1 and the photoelectric conversion layers used in Example 1
and Comparative Example 1. The monolayer films were each formed as
will be described hereinafter. A glass substrate was cleaned by
UV/ozone treatment, and then transferred into a vacuum deposition
machine. With the pressure reduced to 1.times.10-5 Pa inside the
vacuum deposition machine, p-type molecules of Formula (1) or
p-type molecules of Formula (8) were deposited to 40 nm while
rotating a substrate holder, whereby the monolayer film was
obtained. On the photoelectric conversion layers 243 used in
Example 1 and Comparative Example 1, X-ray diffractometry was
performed by an X-ray diffractometer. As an X-ray, a Cu K-alpha
beam is used, for example. By an analysis of X-ray diffraction
patterns so obtained, the photoelectric conversion layers 243 were
determined for the presence or absence of crystallinity.
[0091] Further, in the evaluation of hole mobility, hole mobility
evaluation elements were fabricated, in addition to the organic
photoelectric conversion elements 240, using photoelectric
conversion layers of Example 1 and Comparative Example 1,
respectively. In addition, hole mobility evaluation elements were
fabricated using monolayer films of the p-type materials that were
employed in Example 1 and Comparative Example 1, respectively.
[0092] FIG. 4 is a diagram illustrating a configuration example of
the hole mobility evaluation element 310 in the first embodiment of
the present technology. Over a glass substrate 316 with a 50
nanometer (nm) thick, lower electrode 315 of platinum (Pt) arranged
thereon, a molybdenum oxide layer 314 of molybdenum trioxide
(MoO.sub.3) or the like was deposited with a thickness of 0.8
nanometer (nm). Subsequently, similar to the fabrication of the
organic photoelectric conversion element 240, p-type molecules, a
colorant and n-type molecules (fullerene or the like) were
deposited until their mixed layer (photoelectric conversion layer
313) grew to a thickness of 150 nanometer (nm). Here, the
deposition rates of the p-type molecules, colorant and n-type
molecules are, for example, 0.75 angstrom/sec, 0.75 angstrom/sec
and 0.50 angstrom/sec, respectively.
[0093] A molybdenum oxide layer 312 of molybdenum trioxide
(MoO.sub.3) or the like was next deposited with a thickness of 3
nanometer (nm), followed by deposition of an upper electrode 311 of
gold (Au) with a thickness of 100 nanometer (nm). As a result, the
hole mobility evaluation element 310 was obtained with a
light-receiving area of 1 millimeter (mm) square. In the
photoelectric conversion layer 313, the p-type molecules, colorant
and n-type molecules were set at a ratio of 4:4:2, for example.
[0094] As the hole mobility evaluation element for each monolayer
film, an element which is configured by substituting, for the
photoelectric conversion layer, a monolayer film formed by
depositing only p-type molecules, for example, at 1.00 angstrom per
second to a thickness of 150 nanometer (nm) is used.
[0095] In the evaluation of hole mobility, a bias voltage to be
applied between the electrodes was swept from 0 volt (V) to 10 volt
(V) by using a semiconductor parameter analyzer, whereby a
current-voltage curve was acquired. By fitting the curve to a space
charge-limited current model, a relational expression was
determined between hole mobility and voltage, and the value of hole
mobility at 1 volt (V) was calculated.
[0096] FIGS. 5 and 6 are graphs illustrating examples of results of
X-ray diffractometry in Example 1 in the first embodiment of the
present technology. In these figures, the axis of ordinates
represents X-ray diffraction intensity, and the axis of abscissas
represents diffraction angle. FIG. 5 illustrates the results of
X-ray diffractometry of monolayer films of p-type molecules, and
FIG. 6 illustrates results of X-ray diffractometry of photoelectric
conversion layers. Solid-line loci represent the diffraction
results of Example 1, and dotted-line loci represent the
diffraction results of Comparative Example 1. As exemplified in
FIG. 5, the p-type molecular monolayer films used in Example 1 and
Comparative Example 1 each produced peaks in X-ray diffraction
intensity, and were each crystalline. As exemplified in FIG. 6, on
the other hand, a peak was produced in X-ray diffraction intensity
from the photoelectric conversion layer of Example 1, but no peak
was produced from the photoelectric conversion layer of Comparative
Example 1. It is therefore possible to determine that crystallinity
is present in the photoelectric conversion layer of Example 1 while
crystallinity is absent in the photoelectric conversion layer of
Comparative Example 1. Here, in the determination of the presence
or absence of crystallinity, crystallinity was determined to be
present if there was a peak having a peak intensity higher by 5
times or greater than the noise level of the base line and a shape
with a half-width value of smaller than 1.degree..
[0097] The evaluation results of the individual characteristics in
Example 1 and Comparative Example 1 are presented in the following
table.
TABLE-US-00001 TABLE 1 First embodiment: Comp. Ex. 1 Ex. 1 p-Type
molecules Compound (h) Formula (8) in Scheme (5) External quantum
efficiency (%) 80 77 Dark current (A/cm.sup.2) 1.0E-10 3.0E-10
Standardized response rate (a.u.) 1 10 Hole mobility through
monolayer 1.4E-06 8.1E-08 (cm.sup.2/V s) Monolayer crystallinity
Present Present Hole mobility through 1.9E-05 1.5E-09 photoelectric
conversion layer (cm.sup.2/V-s) Crystallinity of photoelectric
Present Absent conversion layer
[0098] The external quantum efficiency, dark current and
standardized response rate of the photoelectric conversion element
in Example 1 were 80 percent (%), 1.0E-10 ampere per square
centimeter (A/cm.sup.2) and 1. The monolayer of the p-type
molecules used in Example 1 had crystallinity, and its SCLC
(Space-Charge-Limited Current) mobility (in other words, hole
mobility) was 1.4E-6 square centimeter per voltsecond
(cm.sup.2/Vs). The photoelectric conversion layer in the
photoelectric conversion element in Example 1 had crystallinity,
and the SCLC (hole mobility) of the photoelectric conversion layer
was 1.9E-5 square centimeter per voltsecond (cm2/Vs).
[0099] On the other hand, the external quantum efficiency, dark
current and standardized response rate of the photoelectric
conversion element in Comparative Example 1 were 77 percent (%),
3.0E-10 ampere per square centimeter (A/cm.sup.2) and 10. The
monolayer of the p-type molecules used in Comparative Example 1 had
crystallinity, and its SCLC mobility (hole mobility) was 8.1E-8
square centimeter per voltsecond (cm.sup.2/Vs). The photoelectric
conversion layer in the photoelectric conversion element of
Comparative Example 1 had non-crystallinity, and the SCLC mobility
(hole mobility) of the photoelectric conversion layer was 1.5E-9
square centimeter per voltsecond (cm.sup.2/Vs).
[0100] As appreciated from the foregoing, the quantum efficiency
and standardized response rate of the organic photoelectric
conversion element in Example 1 are higher than those of
Comparative Example 1. This is presumably attributable to the fact
that the photoelectric conversion layer using the p-type molecules
of Formula (1) has not only high hole mobility for crystallinity in
the monolayer film but also high hole mobility for crystallinity in
a photoelectric conversion layer that is a mixed layer film and, as
a consequence, the capture rate of carriers from the photoelectric
conversion layer to each electrode increases. In Comparative
Example 1, on the other hand, the hole mobility is low in the
monolayer film despite its crystallinity, and in the photoelectric
conversion layer that is the mixed layer film, the hole mobility is
lower than that in the monolayer film because of non-crystallinity.
The capture rate of carriers hence decreases. As a consequence, the
quantum efficiency and standardized response rate of Comparative
Example 1 are lower than those of Example 1.
[0101] From the X-ray diffraction results illustrated in FIGS. 5
and 6, the p-type molecules of Example 1 retain high crystallinity
in the photoelectric conversion layer despite their co-deposition
with heteroatoms of the colorant and fullerene, presumably for the
reason that, in Example 1 in which .pi. conjugation is extended and
a biphenyl structure and a ring are extended in each substituent,
.pi.-.pi. interaction and CH-.pi. interaction, which are
intermolecular actions that form a herringbone crystal structure,
are strong.
[0102] In Example 1 described above, the compound (h) in Scheme
(5), out of the compounds exemplified by Formula (1), was used as
p-type molecules. However, compounds represented by the following
formula out of the p-type molecules exemplified by Formula (1) may
each also be used.
##STR00027##
[0103] The compounds exemplified by Formula (9) are different from
Example 1 specifically in that instead of R.sub.3 and R.sub.7,
R.sub.2 and R.sub.6 are each a substituted or unsubstituted aryl
group or heteroaryl group. Among the compounds of Formula (9),
compounds represented by the following formula can each also be
used as p-type molecules.
##STR00028##
in which R.sub.2-1 and R.sub.6-1 are each a substituted or
unsubstituted aryl group or heteroaryl group having 4 to 24 carbon
atoms.
[0104] Among the compounds exemplified by Formula (10), compounds
represented by the following formula can each also be used as
p-type molecules.
##STR00029##
[0105] in which R.sub.2-2 and R.sub.6-2 are each a substituted or
unsubstituted aryl group or heteroaryl group having 4 to 18 carbon
atoms.
[0106] Among the compounds exemplified by Formula (10), compounds
represented by the following formula can each also be used as
p-type molecules.
##STR00030##
[0107] Among the compounds exemplified by Formula (12), the
compound represented by the following formula can be also used as
p-type molecules.
##STR00031##
[0108] The compound represented by Formula (13) will be described
in Example 2 of the first embodiment. The compound relating to
Example 2 can be synthesized according to the following reaction
scheme similar to Scheme (5).
##STR00032##
[0109] In Scheme (14), using a four-necked flask under an argon
(Ar) atmosphere, 1-bromo-2-fluoro-4-iodobenzene, 4-biphenylboronic
acid, sodium hydrogen carbonate and PdCl.sub.2(PPh.sub.3).sub.2
were first refluxed with heating in a mixed solution of distilled
water and 1-propanol. Here, the chemical equivalents of
1-bromo-2-fluoro-4-iodobenzene, 4-biphenylboronic acid, sodium
hydrogen carbonate and PdCl.sub.2(PPh.sub.3).sub.2 were "1," "1,"
"3" and "0.003," respectively. After allowed to cool at room
temperature, the precipitated solid was collected by filtration,
dissolved in dichloromethane, and collected by filtration on silica
gel. As a result, a pale orange solid (the intermediate 1 of (b) in
Scheme 14), was obtained with a yield of approximately 91 percent
(%).
[0110] Under an argon (Ar) atmosphere, the intermediate (1) and
diethyl ether were next added to a four-necked flask, followed by
cooling to -72.degree. C. over a dry ice/acetone bath. A 1.6 M
solution of n-butyl lithium in hexane was next added dropwise over
40 minutes, followed by stirring for 150 minutes. Subsequently,
B(OMe).sub.3 was added, and the resulting mixture was allowed to
return to room temperature and was then stirred overnight. Here,
the chemical equivalents of the intermediate (1), n-butyl lithium
and B(OMe).sub.3 were "1," "2.5" and "3.7," respectively. Then, 2N
hydrochloric acid was added to terminate the reaction, followed by
filtration. As a result, a gray solid (the intermediate 2 of (c) in
Scheme 14), was obtained with a yield of approximately 33 percent
(%).
[0111] Under an argon (Ar) atmosphere, the raw material 3 and
dichloromethane were subsequently added to a four-necked flask,
followed by cooling to 0.degree. C. Subsequently, iodine and
bromine were added, and the resulting mixture was allowed to rise
to room temperature, followed by stirring overnight. Here, the
chemical equivalents of the raw material 3, iodine and bromine were
"1," "0.03" and "2.4," respectively. Then, a 10% aqueous solution
of sodium thiosulfate was added to terminate the reaction. Using
chloroform, the reaction mixture was separated into layers. The
organic layer was dried over anhydrous magnesium sulfate.
Subsequently, the dried organic layer was filtered, and purified by
column chromatography. As a result, yellow crystals (the
intermediate 3 of (e) in Scheme 14), was obtained with a yield of
approximately 80 percent (%).
[0112] Under an argon (Ar) atmosphere, the intermediate (2), the
intermediate (3), toluene, ethanol, sodium carbonate,
PdCl.sub.3(PPh.sub.3).sub.2 and distilled water were then added to
a four-necked flask, and were refluxed with heating. Here, the
chemical equivalents of the intermediate (3), the intermediate (2),
sodium carbonate and PdCl.sub.3(PPh.sub.3).sub.2 were "1," "3," "5"
and "0.009," respectively. After allowed to cool at room
temperature, the precipitated solid was collected by filtration.
After the solid was then dissolved in monochlorobenzene, the
resulting solution was filtered using celite and silica gel.
Heptane was added to the filtrate to prepare a slurry mixture, and
the slurry mixture was filtered. As a result, a pale yellow solid
((f) in Scheme 14, in other words, the intermediate (4) containing
impurities), was obtained with a yield of 95 percent (%).
[0113] Under an argon (Ar) atmosphere, the intermediate (4),
NaO-t-Bu and NMP were subsequently added to a four-necked flask,
following by stirring overnight at 160 to 170.degree. C. The
heating was then stopped, and the resulting reaction mixture was
allowed to cool at room temperature. Subsequently, the reaction
mixture was filtered and washed with methanol. As a result, a pale
gray solid (crude product of Example 2) was obtained with a crude
yield of 93 percent (%). Sublimation purification was then
conducted to obtain the compound of Example 2 as exemplified by
Formula (13).
[0114] FIGS. 7 and 8 are graphs illustrating examples of results of
X-ray diffractometry in Example 2 of the first embodiment of the
present technology. In these figures, the axis of ordinates
represents X-ray diffraction intensity, and the axis of abscissas
represents diffraction angle. FIG. 7 illustrates the results of
X-ray diffractometry of monolayer films of p-type molecules, and
FIG. 8 illustrates results of X-ray diffractometry of photoelectric
conversion layers. Solid-line loci represent the diffraction
results of Example 1, fine-dotted-line loci represent the
diffraction results of Comparative Example 1, and
coarse-dotted-line loci represent the diffraction results of
Example 2.
[0115] The evaluation results of the individual characteristics of
Example 1, Example 2 and Comparative Example 1 are presented in the
following table. Further, these device structures are all
bulk-heterostructures.
TABLE-US-00002 TABLE 2 First First embodiment: embodiment: Comp.
Ex. 1 Ex. 2 Ex. 1 p-Type molecules Compound (h) Compound (g)
Formula in Scheme (5) in Scheme (14) (8) External quantum
efficiency 80 94 77 (%) Dark current (A/cm.sup.2) 1.0E-10 1.0E-10
3.0E-10 Standardized response rate 1 0.4 10 (a.u.) Hole mobility
through 1.4E-06 2.7E-06 8.1E-08 monolayer (cm.sup.2/V s) Monolayer
crystallinity Present Present Present Hole mobility through 1.9E-05
5.1E-05 1.5E-09 photoelectric conversion layer (cm.sup.2/V s)
Crystallinity of photoelectric Present Present Absent conversion
layer
[0116] From a comparison between Example 2 and Comparative Example
1, it is appreciated that in Example 2, the crystallinity in the
monolayer is retained even in the photoelectric conversion layer
(bulk-heterostructure). This phenomenon is similar in tendency to
the results of the compound (h) (Example 1) in Scheme 5. The
comparison between Example 2 and Comparative Example 1 also
indicates that Example 2, in which the photoelectric conversion
layer has a high crystallinity, is superior in external quantity
efficiency and response characteristics and that the retention of
crystallinity in a photoelectric conversion layer is important for
improved element characteristics. Therefore, it is essential for
improved element characteristics to conduct molecular design so
that the interaction between p-type molecules becomes greater, and
as the positions of substituents in Formula (1), the combination of
R.sub.3 and R.sub.7 is preferred with the combination of R.sub.2
and R.sub.6 being more preferred. In a case of being named
according to the IUPAC (International Union of Pure and Applied
Chemistry), the positions of substitution on the mother skeleton
are preferably the 2- and 9-positions, more preferably the 3- and
10-positions.
[0117] It is to be noted that among the compounds exemplified by
Formula (1), compounds represented by the following formulas can be
used.
##STR00033##
[0118] The above-described compound of Example 1 is one of the
compounds exemplified by Formula (15). Among the compounds of
Formula (15), compounds represented by the following formula can
each also be used as p-type molecules in addition to the compound
of Example 1.
##STR00034##
in which R.sub.3-1 and R.sub.7-1 are each a substituted or
unsubstituted aryl group or heteroaryl group having 4 to 24 carbon
atoms.
[0119] Among the compounds exemplified by Formula (16), the
compounds represented by the following formula can each be
used.
##STR00035##
in which R.sub.3-2 and R.sub.7-2 are each a substituted or
unsubstituted aryl group or heteroaryl group having 4 to 18 carbon
atoms.
[0120] Among the compounds exemplified by Formula (16), compounds
represented by the following formula can each also be used in
addition to the compounds of Formula (17).
##STR00036##
[0121] Among the compounds exemplified by Formula (18), the
compound represented by the following formula can be used.
##STR00037##
[0122] As described above, according to the first embodiment of the
present technology, the organic photoelectric conversion element
240 can be provided with improved quantum efficiency and
standardized response rate owing to the formation of the
photoelectric conversion layer 243 including the p-type molecules
represented by Formula (1).
2. Second Embodiment
[0123] In the first embodiment described above, the quantum
efficiency and response rate were improved using, as p-type
molecules, the compounds represented by Formula (1). However, it is
also possible to make improvements in quantum efficiency and
response rate by using, as p-type molecules, compounds other than
those of Formula (1). An organic photoelectric conversion element
240 in this second embodiment is different from that in the first
embodiment in that a compound other than those of Formula (1) are
included.
[0124] The organic photoelectric conversion element 240 in the
second embodiment is different from that in the first embodiment in
that a photoelectric conversion layer 243 includes p-type molecules
represented by Formula (9) instead of the p-type molecules
represented by Formula (1).
##STR00038##
in which A represents any one of oxygen, sulfur or selenium, any
one of R.sub.21 to R.sub.25 represents a substituted or
unsubstituted aryl or heteroaryl having 4 to 30 carbon atoms, the
remainder of R.sub.21 to R.sub.25 each represent hydrogen, any one
of R.sub.26 to R.sub.30 represents a substituted or unsubstituted
aryl or heteroaryl having 4 to 30 carbon atoms, and the remainder
of R.sub.26 to R.sub.30 each represent hydrogen.
[0125] As the positions of substitution by aryl groups or
heteroaryl groups in Formula (20), the combination of R.sub.23 and
R.sub.28 is most desired for the reason that a linear, fused-ring
molecule of high planarity like Formula (9) is known to have a
herringbone crystal structure and to form a two-dimensional carrier
transport path and the molecular shape is desirably linear in order
to have such a crystal structure. The selection of aryl groups or
heteroaryl groups as R.sub.23 and R.sub.28 allows the positions of
substitution to be linear.
[0126] For a similar reason, even if each aryl group is not single
but is connected to a biphenyl group or a terphenyl group, each
ring of the aryl group is desirably connected at the para position
thereof to the biphenyl or terphenyl group from the viewpoint of
providing linearity. If a five-membered ring such as a bithienyl
group or terthienyl group is connected to an aryl group, the
connection via the carbon at the alpha position of the thiophene
ring is desired for higher linearity. Further, if a phenyl group
and a thienyl group are connected to each other, the connection
between the para-position of the phenyl group and the alpha
position of the thienyl group is desired for a similar reason. In
addition, if each aryl group or each heteroaryl group includes a
fused multi-ring group such as naphthalene ring, benzothiophene
ring or indole ring, they are desirably also connected to provide
high linearity.
[0127] The substituents of R.sub.21 to R.sub.25 and of R.sub.26 to
R.sub.30 are desirably the same, and in addition the symmetry of
the positions of substitution is desirably twofold symmetry, for
the reason that, when having a crystal structure, higher symmetry
leads to smaller anisotropy and to a smaller band dispersion
width.
Example 1
[0128] A description will next be made about Example 1 in the
second embodiment. In Example 1, p-type molecules were synthesized
according to the following reaction scheme with reference to Scheme
(2) in Shoji Shinamura, et. al., "Linear- and Angular-Shaped
Naphthodithiophenes: Selective Synthesis, Properties, and
Application to Organic Field-Effect Transistors," J. Am. Chem.
Soc., 2011, 133, 5024-5035, and sublimation purification was
conducted for the resulting reaction product.
##STR00039##
[0129] The compound (d) in Scheme (21) is an example of the
compounds of Formula (20). In Example 1, the preparation processes
of the parts other than p-type molecules were similar those in
Example 1.
Comparative Example 1
[0130] A description will next be made about Comparative Example 1.
p-Type molecules according to Comparative Example 1 were
synthesized according to the following reaction scheme with
reference to Scheme (2) in Shoji Shinamura, et. al., "Linear- and
Angular-Shaped Naphthodithiophenes: Selective Synthesis,
Properties, and Application to Organic Field-Effect Transistors,"
J. Am. Chem. Soc., 2011, 133, 5024-5035, and sublimation
purification was conducted for the resulting reaction product.
Compared with the compound (d) in Scheme (21) in Example 1, the
compound (d) in Scheme (22) lacks of one phenyl group in each of
the substituents at the opposite terminals.
##STR00040##
Comparative Example 2
[0131] A description will next be made about a comparative example
in the first embodiment. In Comparative Example 2, BQD represented
by Formula (8) of a quinacridone derivative was used as p-type
molecules.
[Characteristics of Photoelectric Conversion Elements]
[0132] Evaluation methods of characteristics of an organic
photoelectric conversion element according to Example 1 and organic
photoelectric conversion elements according to Comparative Examples
1 and 2 were similar to those in the first embodiment.
[0133] FIGS. 9 and 10 are graphs illustrating examples of results
of X-ray diffractometry in the second embodiment of the present
technology. In these figures, the axis of ordinates represents
X-ray diffraction intensity, and the axis of abscissas represents
diffraction angle. FIG. 9 illustrates the results of X-ray
diffractometry of monolayer films of p-type molecules, and FIG. 10
illustrates results of X-ray diffractometry of photoelectric
conversion layers. Solid-line loci represent the diffraction
results of Example 1, dotted-line loci represent the diffraction
results of Comparative Example 1, and dashed-line loci represent
the diffraction results of Comparative Example 2. As exemplified in
FIG. 9, the p-type molecular monolayer films used in Example 1,
Comparative Example 1 and Comparative Example 2 in the second
embodiment each produced one or more peaks in X-ray diffraction
intensity, and were each crystalline. As exemplified in FIG. 10, on
the other hand, peaks were produced in X-ray diffraction intensity
from the photoelectric conversion layer of Example 1 in the second
embodiment, but no peak was produced from the photoelectric
conversion layers of Comparative Examples 1 and 2. It is therefore
possible to determine that crystallinity is present in the
photoelectric conversion layer of Example 1 while crystallinity is
absent in the photoelectric conversion layers of Comparative
Examples 1 and 2. Here, in the determination of the presence or
absence of crystallinity, crystallinity was determined to be
present if there was a peak having a peak intensity higher by 5
times or greater than the noise level of the base line and a shape
with a half-width value of smaller than 1.degree..
[0134] The evaluation results of the individual characteristics in
Example 1 and comparative examples are presented in the following
table.
TABLE-US-00003 TABLE 3 Second embodiment: Comp. Comp. Ex. 1 Ex. 1
Ex. 2 p-Type molecules Compound Compound Formula (8) (d) in (d) of
Formula (10) Formula (11) External quantum 81 22 77 efficiency (%)
Dark current (A/cm.sup.2) 2.0E-10 8.0E-10 3.0E-10 Standardized
response 2 >300 10 rate (a.u.) Hole mobility through 3.1E-05
3.9E-04 8.1E-08 monolayer (cm.sup.2/V s) Monolayer crystallinity
Present Present Present Hole mobility through 7.1E-05 2.0E-08
1.5E-09 photoelectric conversion layer (cm.sup.2/V s) Crystallinity
of Present Absent Absent photoelectric conversion layer
[0135] The external quantum efficiency, dark current and
standardized response rate of the photoelectric conversion element
in Example 1 were 81 percent (%), 2.0E-10 ampere per square
centimeter (A/cm.sup.2) and 2. The monolayer of the p-type
molecules used in Example 1 had crystallinity, and its SCLC
(Space-Charge-Limited Current) mobility (in other words, hole
mobility) was 3.1E-5 square centimeter per voltsecond
(cm.sup.2/Vs). The photoelectric conversion layer in the
photoelectric conversion element in Example 1 had crystallinity,
and the SCLC mobility (hole mobility) of the photoelectric
conversion layer was 7.1E-5 square centimeter per voltsecond
(cm.sup.2/Vs).
[0136] The external quantum efficiency, dark current and
standardized response rate of the photoelectric conversion element
in Comparative Example 1 were 22 percent (%), 8.0E-10 ampere per
square centimeter (A/cm.sup.2) and >300. The monolayer of the
p-type molecules used in Comparative Example 1 had crystallinity,
and its SCLC mobility (hole mobility) was 3.9E-4 square centimeter
per voltsecond (cm.sup.2/Vs). The photoelectric conversion layer in
the photoelectric conversion element of the comparative example had
non-crystallinity, and the SCLC mobility (hole mobility) of the
photoelectric conversion layer was 2.0E-8 square centimeter per
voltsecond (cm.sup.2/Vs). On the other hand, the characteristics of
the photoelectric conversion element in Comparative Example 2 were
as described above.
[0137] As appreciated from the foregoing, the quantum efficiency
and standardized response rate of the organic photoelectric
conversion element in Example 1 are higher than those of
Comparative Examples 1 and 2. This is presumably attributable to
the fact that the photoelectric conversion layer using the p-type
molecules of Formula (20) has high hole mobility for its
crystallinity and, as a consequence, the capture rate of carriers
from the photoelectric conversion layer to each electrode
increases. In each of Comparative Examples 1 and 2, on the other
hand, the photoelectric conversion layer is non-crystalline so that
the hole mobility is low and the capture rate of carriers is low.
As a consequence, the quantum efficiency and standardized response
rate of each comparative example are lower than those of Example
1.
[0138] From X-ray diffraction results, the p-type molecules of
Example 1 retain high crystallinity in the photoelectric conversion
layer despite their co-deposition with heteroatoms of the colorant
and fullerene, presumably for the reason that the
biphenyl-substituted derivative of Example 1 has stronger CH-.pi.
interaction, which is intermolecular action that forms a
herringbone crystal structure, than the monophenyl-substituted
derivative of Comparative Example 1.
[0139] From a comparison with BQD of Comparative Example 2, the
higher quantum efficiency of the biphenyl-substituted derivative of
Example 1 than the phenyl-substituted derivative of Comparative
Example 1 can also be attributed to the fact that the domain size
had enlarged for not only the crystallinity of the photoelectric
conversion layer but also promoted phase separation in the
photoelectric conversion layer. An increase in domain size is
considered to lead to the diffusion of excitons, which are formed
in the colorant, to an interface so that the excitons are
deactivated before separation into charges. In the photoelectric
conversion layer according to the present technology, the
biphenyl-substituted derivative presumably has, compared to the
phenyl-substituted derivative, intermolecular interaction such that
upon formation of a film by vapor deposition, the phase separation
size between the colorant and the n-type molecules becomes an
appropriate size not greater than an excitation diffusion
length.
[0140] According to the second embodiment of the present technology
as described above, the photoelectric conversion layer 243 was
formed, with p-type molecules of Formula (9) included therein, in
the organic photoelectric conversion element 240 so that the
organic photoelectric conversion element 240 was successfully
provided with the improved quantum efficiency and response
rate.
[0141] It is to be noted that the above-described embodiments
merely present examples for embodying the present technology, and
the matters in the embodiments and the invention-specifying
features in the claims have corresponding relationships,
respectively. Similarly, the invention-specifying features in the
claims and the matters identified in the same terms in the
embodiments of the present technology have corresponding
relationships, respectively. However, the present technology should
not be limited to the embodiments, but can be embodied by applying
various modifications to the embodiments within a scope not
departing from its spirit.
[0142] It is also to be noted that the advantageous effects
described in the Description are merely illustrative and are not
limiting, and there may be other advantageous effects.
[0143] It is also to be noted that the present technology may have
configurations as will be described hereinafter.
[0144] (1) An organic photoelectric conversion element
including:
[0145] p-type molecules represented by Formula (1) in a
photoelectric conversion layer:
##STR00041##
in which
[0146] in the Formula (1), A represents any one of oxygen, sulfur
or selenium, any one of R.sub.1 to R.sub.4 represents a substituted
or unsubstituted aryl or heteroaryl having 4 to 30 carbon atoms,
the remainder of R.sub.1 to R.sub.4 each represent hydrogen, any
one of R.sub.5 to R.sub.8 represents a substituted or unsubstituted
aryl or heteroaryl having 4 to 30 carbon atoms, and the remainder
of R.sub.5 to R.sub.8 each represent hydrogen.
[0147] (2) The organic photoelectric conversion element as
described above in (1), in which
[0148] the photoelectric conversion layer further includes n-type
molecules, and
[0149] the n-type molecules include a fullerene or a fullerene
derivative.
[0150] (3) The organic photoelectric conversion element as
described above in (2), in which
[0151] the n-type molecules amount to a volume fraction of 10 to 50
percent relative to the photoelectric conversion layer.
[0152] (4) The organic photoelectric conversion element as
described above in (2) or (3), in which
[0153] the n-type molecules include the fullerene derivative
represented by any one of Formula (2) or (3):
##STR00042##
[0154] in the Formulae (2) and (3), R independently represents
hydrogen, halogen, linear, branched or cyclic alkyl, phenyl, a
linear or fused-ring aromatic-containing group, a
halogenide-containing group, partial fluoroalkyl, perfluoroalkyl,
silylalkyl, silylalkoxy, arylsilyl, arylsulfanyl, alkylsulfanyl,
arylsulfonyl, alkylsulfonyl, arylsulfido, alkylsulfido, amino,
alkylamino, arylamino, hydroxy, alkoxy, acylamino, acyloxy,
carbonyl, carboxy, carboxamido, carboalkoxy, acyl, sulfonyl, cyano,
nitro, a chalcogenide-containing group, phosphino or phosphono, or
a derivative thereof, and n and m each stand for an integer.
[0155] (5) The organic photoelectric conversion element as
described above in any one of (1) to (4), in which
[0156] the photoelectric conversion layer further includes a
colorant, and
[0157] the colorant has a maximum absorption coefficient of not
smaller than 50000 cm.sup.-1 in a wavelength range of visible
light.
[0158] (6) The organic photoelectric conversion element as
described above in (5), in which
[0159] the colorant amounts to a volume fraction of 20 to 80
percent relative to the photoelectric conversion layer.
[0160] (7) The organic photoelectric conversion element as
described above in (5) or (6), in which
[0161] the colorant includes a subphthalocyanine derivative.
[0162] (8) The organic photoelectric conversion element as
described above in (7), in which
[0163] the colorant includes a subphthalocyanine derivative
represented by Formula (4):
##STR00043##
and
[0164] R.sub.9 to R.sub.20 in the Formula (4) are each
independently selected from a group including hydrogen, halogen,
linear, branched or cyclic alkyl, thioalkyl, thioaryl,
arylsulfonyl, alkylsulfonyl, amino, alkylamino, arylamino, hydroxy,
alkoxy, acylamino, acyloxy, phenyl, carboxy, carboxamido,
carboalkoxy, acyl, sulfonyl, cyano and nitro, M represents boron or
a divalent or trivalent metal, and X represents an anionic
group.
[0165] (9) The organic photoelectric conversion element as
described above in any one of (1) to (8), in which
[0166] the p-type molecules amount to a volume fraction of 10 to 70
percent relative to the photoelectric conversion layer.
[0167] (10) The organic photoelectric conversion element as
described above in any one of (1) to (9), in which
[0168] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (9) out of the
compounds represented by Formula (1):
##STR00044##
[0169] (11) The organic photoelectric conversion element as
described above in (10), in which
[0170] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (10) out of the
compounds represented by Formula (9):
##STR00045##
and
[0171] R.sub.2-1 and R.sub.6-1 are each a substituted or
unsubstituted aryl group or heteroaryl group having 4 to 24 carbon
atoms.
[0172] (12) The organic photoelectric conversion element as
described above in (11), in which
[0173] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (11) out of the
compounds represented by Formula (10):
##STR00046##
[0174] in the Formula (11), R.sub.2-2 and R.sub.6-2 are each a
substituted or unsubstituted aryl group or heteroaryl group having
4 to 18 carbon atoms.
[0175] (13) The organic photoelectric conversion element as
described above in (11), in which
[0176] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (12) out of the
compounds represented by Formula (10):
##STR00047##
[0177] (14) The organic photoelectric conversion element as
described above in (13), in which
[0178] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (13) out of the
compounds represented by Formula (12):
##STR00048##
[0179] (15) The organic photoelectric conversion element as
described above in any one of (1) to (9), in which
[0180] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (15) out of the
compounds represented by Formula (1):
##STR00049##
[0181] (16) The organic photoelectric conversion element as
described above in (15), in which
[0182] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (16) out of the
compounds represented by Formula (15):
##STR00050##
and
[0183] in the Formula (16), R.sub.3-1 and R.sub.7-1 are each a
substituted or unsubstituted aryl group or heteroaryl group having
4 to 24 carbon atoms.
[0184] (17) The organic photoelectric conversion element as
described above in (16), in which
[0185] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (17) out of the
compounds represented by Formula (16):
##STR00051##
and
[0186] in the Formula (17), R.sub.3-2 and R.sub.7-2 are each a
substituted or unsubstituted aryl group or heteroaryl group having
4 to 18 carbon atoms.
[0187] (18) The organic photoelectric conversion element as
described above in (16), in which
[0188] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (18) out of the
compounds represented by Formula (16):
##STR00052##
[0189] (19) The organic photoelectric conversion element as
described above in (18), in which
[0190] the photoelectric conversion layer includes, as the p-type
molecules, a compound represented by Formula (19) out of the
compounds represented by Formula (18):
##STR00053##
[0191] (20) An organic photoelectric conversion element
including:
[0192] p-type molecules represented by Formula (20) in a
photoelectric conversion layer:
##STR00054##
in which
[0193] in the Formula (20), A represents any one of oxygen, sulfur
or selenium, any one of R.sub.21 to R.sub.25 represents a
substituted or unsubstituted aryl or heteroaryl having 4 to 30
carbon atoms, the remainder of R.sub.21 to R.sub.25 represent
hydrogen, any one of R.sub.26 to R.sub.30 represents a substituted
or unsubstituted aryl or heteroaryl having 4 to 30 carbon atoms,
and the remainder of R.sub.26 to R.sub.30 represent hydrogen.
[0194] (21) The organic photoelectric conversion element as
described above in (20), in which
[0195] the photoelectric conversion layer further includes n-type
molecules, and
[0196] the n-type molecules include a fullerene or a fullerene
derivative.
[0197] (22) The organic photoelectric conversion element as
described above in (21), in which
[0198] the n-type molecules amount to a volume fraction of 10 to 50
percent relative to the photoelectric conversion layer.
[0199] (23) The organic photoelectric conversion element as
described above in (21) or (22), in which
[0200] the n-type molecules include the fullerene derivative
represented by any one of Formula (2) or (3):
##STR00055##
and
[0201] in the Formulae (2) and (3), R independently represents
hydrogen, halogen, linear, branched or cyclic alkyl, phenyl, a
linear or fused-ring aromatic-containing group, a
halogenide-containing group, partial fluoroalkyl, perfluoroalkyl,
silylalkyl, silylalkoxy, arylsilyl, arylsulfanyl, alkylsulfanyl,
arylsulfonyl, alkylsulfonyl, arylsulfido, alkylsulfido, amino,
alkylamino, arylamino, hydroxy, alkoxy, acylamino, acyloxy,
carbonyl, carboxy, carboxamido, carboalkoxy, acyl, sulfonyl, cyano,
nitro, a chalcogenide-containing group, phosphino or phosphono, or
a derivative thereof, and n and m each stand for an integer.
[0202] (24) The organic photoelectric conversion element as
described above in (20), in which
[0203] the photoelectric conversion layer further includes a
colorant, and
[0204] the colorant has a maximum absorption coefficient of not
smaller than 50000 cm.sup.-1 in a wavelength range of visible
light.
[0205] (25) The organic photoelectric conversion element as
described above in (24), in which
[0206] the colorant amounts to a volume fraction of 20 to 80
percent relative to the photoelectric conversion layer.
[0207] (26) The organic photoelectric conversion element as
described above in (24) or (25), in which the colorant includes a
subphthalocyanine derivative.
[0208] (27) The organic photoelectric conversion element as
described above in (26), in which
[0209] the colorant includes a subphthalocyanine derivative
represented by Formula (4):
##STR00056##
and
[0210] R.sub.9 to R.sub.20 in the Formula (4) are each
independently selected from a group including hydrogen, halogen,
linear, branched or cyclic alkyl, thioalkyl, thioaryl,
arylsulfonyl, alkylsulfonyl, amino, alkylamino, arylamino, hydroxy,
alkoxy, acylamino, acyloxy, phenyl, carboxy, carboxamido,
carboalkoxy, acyl, sulfonyl, cyano and nitro, M represents boron or
a divalent or trivalent metal, and X represents an anionic
group.
[0211] (28) The organic photoelectric conversion element as
described above in any one of (20) to (27), in which
[0212] the p-type molecules amount to a volume fraction of 10 to 70
percent relative to the photoelectric conversion layer.
REFERENCE SIGNS LIST
[0213] 200 Solid-state imaging device [0214] 210 Row scanning
circuit [0215] 220 Pixel array section [0216] 230 Pixel [0217] 231
Transfer transistor [0218] 232 Floating diffusion layer [0219] 233
Amplifier transistor [0220] 234 Selection transistor [0221] 240
Organic photoelectric conversion element [0222] 241, 311 Upper
electrode [0223] 242 Charge transport layer [0224] 243, 313
Photoelectric conversion layer [0225] 244, 315 Lower electrode
[0226] 245, 316 Substrate [0227] 250 DAC [0228] 260 Signal
processing section [0229] 270 Timing control section [0230] 280
Column scanning circuit [0231] 310 Hole mobility evaluation element
[0232] 312, 314 Molybdenum oxide layer
* * * * *