Photoelectric conversion element and imaging device

Abstract

A first photoelectric conversion element according to one embodiment of the present disclosure includes: a first electrode; a second electrode arranged opposite to the first electrode; and a photoelectric conversion layer provided between the first electrode and the second electrode, the photoelectric conversion layer containing, as a first organic semiconductor material, fullerene C 60 or fullerene C 70 and a second organic semiconductor material having an ionization potential of 0 to 5.0 eV.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a photoelectric conversion element in which, for example, an organic material is used, and an imaging device including the photoelectric conversion element. BACKGROUND

[0002] For example, Patent Literature 1 discloses an imaging device in which light receiving sections for detecting light of wavelength ranges different from each other are laminated.

[0003] LIST OF CITATIONS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2003-332551 SUMMARY

[0006] Incidentally, it is demanded that imaging devices have higher sensitivity.

[0007] It is desirable to provide a photoelectric conversion element and an imaging device that can improve sensitivity.

[0008] A first photoelectric conversion element according to an embodiment of the present disclosure includes: a first electrode; a second electrode disposed opposite the first electrode; and a photoelectric conversion layer disposed between the first electrode and the second electrode. The photoelectric conversion layer contains, as a first organic semiconductor material, fullerene C 60 or fullerene C 70 and a second organic semiconductor material having an ionization potential of 0 or more and 5.0 eV or less.

[0009] A first imaging device according to an embodiment of the present disclosure includes, for each of a plurality of pixels, one or more first photoelectric conversion elements according to the above-described embodiment of the present disclosure.

[0010] A second photoelectric conversion element according to an embodiment of the present disclosure includes: a first electrode; a second electrode disposed opposite the first electrode; and a photoelectric conversion layer disposed between the first electrode and the second electrode. The photoelectric conversion layer contains, as a first organic semiconductor material, fullerene C 60 or fullerene C 70 and a second organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in a ground state or an excited state.

[0011] A second imaging device according to an embodiment of the present disclosure includes, for each of a plurality of pixels, one or more second photoelectric conversion elements according to the above-described embodiment of the present disclosure.

[0012] In the first photoelectric conversion element according to an embodiment of the present disclosure and the first imaging device according to the embodiment, fullerene C60 or fullerene C 70 and a second organic semiconductor material having an ionization potential of 0 or more and 5.0 eV or less, to form a photoelectric conversion layer. In the second photoelectric conversion element according to the embodiment of the present disclosure and the second imaging device according to the embodiment, fullerene C 60 or fullerene C 70 and a second organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in a ground state or an excited state, to form a photoelectric conversion layer. Thus, a plurality of excitons generated in a fullerene aggregate are effectively subjected to charge separation. BRIEF DESCRIPTION OF DRAWINGS

[0013] [ Figure 1 ] Figure 1 is a cross-sectional schematic view showing an example of a schematic configuration of a photoelectric conversion element according to a first embodiment of the present disclosure.

[0014] [ Figure 2 ] Figure 2 is a block diagram showing a configuration of an imaging device including Figure 1 the photoelectric conversion element shown in FIG. 1.

[0015] [ Figure 3 ] Figure 3 is a graph showing an energy spectrum of fullerene C 60 in an excited state.

[0016] [ Figure 4 ] Figure 4 is a schematic view illustrating a relationship between fullerene C 60 molecules and dopant molecules in an organic photoelectric conversion layer.

[0017] [ Figure 5 ] Figure 5 is a graph showing an energy difference between a first proximity fullerene C 60 and a second proximity fullerene C 60 when a dopant cation is doped in a fullerene C 60 aggregate system.

[0018] [ Figure 6 ] Figure 6 is a cross-sectional schematic view showing an example of a schematic configuration of a photoelectric conversion element according to a second embodiment of the present disclosure.

[0019] [ Figure 7 ] Figure 7 is a schematic view illustrating a relationship between fullerene C 60 molecules and dopant molecules in an organic photoelectric conversion layer.

[0020] [ Figure 8 ]Figure 8 is a graph showing an energy difference between a first proxima fullerene C 60 when a dipole moment is doped in an aggregation system 60 and a second proxima fullerene C 60 .

[0021] [ Figure 9 ] Figure 9 is a graph showing a relationship between an energy difference between a first proxima fullerene C 60 and a second proxima fullerene C 60 and a size of a dipole moment.

[0022] [ Figure 10 ] Figure 10 is a cross-sectional schematic view showing an example of a schematic configuration of a photoelectric conversion element according to Modified Example 1 of the present disclosure.

[0023] [ Figure 11 ] Figure 11 is a cross-sectional schematic view showing another example of a schematic configuration of a photoelectric conversion element according to Modified Example 1 of the present disclosure.

[0024] [ Figure 12 ] Figure 12 is a cross-sectional schematic view showing an example of a schematic configuration of a photoelectric conversion element according to Modified Example 2 of the present disclosure.

[0025] [ Figure 13 ] Figure 13 is a block diagram showing a configuration example of an electronic device including the imaging device shown in Figure 2 .

[0026] [ Figure 14 ] Figure 14 is a graph showing an example of a schematic configuration of an endoscopic surgery system.

[0027] [ Figure 15 ] Figure 15 is a block diagram showing an example of a functional configuration of a camera head and a camera control unit (CCU).

[0028] [ Figure 16 ] Figure 16 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0029] [ Figure 17 ] Figure 17 is a graph that assists in explaining an example of a mounting position of an outside-vehicle information detection unit and an imaging unit. DETAILED DESCRIPTION

[0030] Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. The following description is a specific example of the present disclosure, but the present disclosure is not limited to the following modes. In addition, the present disclosure is not limited to the arrangement, size, and dimensional ratio of each component shown in each drawing. Note that the description is given in the following order.

[0031] 1. First Embodiment (Example of photoelectric conversion element having an organic photoelectric conversion layer containing a fullerene and an organic semiconductor material with an ionization potential of 5.0 eV or less)

[0032] 1-1. Configuration of photoelectric conversion element

[0033] 1-2. Configuration of imaging device

[0034] 1-3. Operation and effects

[0035] 2. Second Embodiment (Example of photoelectric conversion element having an organic photoelectric conversion layer containing a fullerene and an organic semiconductor material with an electric dipole moment of 10 Debye or more and 30 Debye or less in a ground state or an excited state)

[0036] 2-1. Configuration of photoelectric conversion element

[0037] 2-2. Operation and effects

[0038] 3. Modified Example

[0039] 3-1. Modified Example 1 (Example of adding a spectrum adjustment layer)

[0040] 3-2. Modified Example 2 (Example of laminating organic photoelectric conversion layers with different spectral characteristics)

[0041] 4. Application Example

[0042] 5. Application Example

[0043] <1. First Embodiment>

[0044] Figure 1 An example of a cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10A) according to the first embodiment of the present disclosure is shown. Figure 2 An example of a cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10A) according to the first embodiment of the present disclosure is shown. Figure 1An example of the overall configuration of an imaging device (imaging device 1) including the photoelectric conversion element 10A is shown. One pixel (unit pixel P) in the imaging device 1 such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor used in an electronic device such as a digital camera or a video camera, for example, includes the photoelectric conversion element 10A. The photoelectric conversion element 10A according to the present embodiment includes an organic photoelectric conversion section 20. The organic photoelectric conversion layer 22 included in the organic photoelectric conversion section 20 is formed by using a fullerene (fullerene C 60 or a fullerene C 70 ) and an organic semiconductor material having an ionization potential of 5.0 eV or less.

[0045] (1-1. Configuration of photoelectric conversion element)

[0046] The photoelectric conversion element 10A includes, for example, one organic photoelectric conversion section 20. The organic photoelectric conversion section 20 includes an organic photoelectric conversion layer 22 between a lower electrode 21 (first electrode) and an upper electrode 23 (second electrode) arranged opposite to each other. The organic photoelectric conversion layer 22 is formed by using the above-described organic semiconductor material as an organic material. The organic photoelectric conversion section 20 detects a part or all of wavelengths in the visible light region (for example, 400 nm or more and 760 nm or less).

[0047] In the present embodiment, above (light incident side) the organic photoelectric conversion section 20, a color filter 51 (color filters 51R, 51G, and 51B) is provided for each unit pixel P (unit pixels Pr, Pg, and Pb), respectively. The color filter 51 (color filters 51R, 51G, and 51B) selectively transmits red light (R), green light (G), and blue light (B). Therefore, in the unit pixel Pr provided with the color filter 51R, the organic photoelectric conversion section 20 detects red light that has passed through the color filter 51R and generates signal charges corresponding to the red light (R). In the unit pixel Pg provided with the color filter 51G, the organic photoelectric conversion section 20 detects green light that has passed through the color filter 51G and generates signal charges corresponding to the green light (G). In the unit pixel Pb provided with the color filter 51B, the organic photoelectric conversion section 20 detects blue light that has passed through the color filter 51B and generates signal charges corresponding to the blue light (B).

[0048] The photoelectric conversion element 10A also includes, for example, an inorganic photoelectric conversion section 32. The inorganic photoelectric conversion section 32 is formed to be embedded in the semiconductor substrate 30. The inorganic photoelectric conversion section 32 detects light in a wavelength range different from that of the organic photoelectric conversion section 20 and performs photoelectric conversion. In other words, the organic photoelectric conversion section 20 and the inorganic photoelectric conversion section 32 detect light in respective wavelength ranges different from each other and perform photoelectric conversion. Specifically, the organic photoelectric conversion section 20 detects wavelengths in the visible light region, and the inorganic photoelectric conversion section 32 detects wavelengths in the infrared light region (for example, 700 nm or more and 1500 nm or less).

[0049] The organic photoelectric conversion section 20 and the inorganic photoelectric conversion section 32 are, for example, stacked in the vertical direction. Specifically, the organic photoelectric conversion section 20 is, for example, provided on the light incident side S1, and is, for example, provided on the first surface 30A (back surface) side of the semiconductor substrate 30.

[0050] Therefore, light in the visible light region (R, G, and B) among the light in each of the colors of the color filters 51R, 51G, and 51B is respectively absorbed by the organic photoelectric conversion section 20. The other light passes through the organic photoelectric conversion section 20. Specifically, light in the infrared light region passes through the organic photoelectric conversion section 20. The inorganic photoelectric conversion section 32 of each of the unit pixels Pr, Pg, and Pb detects such light in the infrared light region (hereinafter simply referred to as infrared light (IR)) that has passed through the organic photoelectric conversion section 20. Each of the unit pixels Pr, Pg, and Pb generates signal charges corresponding to the infrared light (IR). In other words, the imaging device 1 including the photoelectric conversion element 10A is capable of simultaneously generating a visible light image and an infrared light image.

[0051] Note that, in the present embodiment, a case in which an electron among a pair of an electron and a hole (electron-hole pair) generated by photoelectric conversion is read out as a signal charge (a case in which an n-type semiconductor region is used as a photoelectric conversion layer) is described. In addition, in the drawings, “+ (plus)” added to “n” indicates that the concentration of n-type impurities is high.

[0052] The second surface 30B (front surface) of the semiconductor substrate 30 is, for example, provided with a charge holding section 33 and a pixel transistor and a multilayer wiring layer 40 not shown. In the multilayer wiring layer 40, for example, wiring layers 41, 42, and 43 are stacked in an insulating layer 44.

[0053] Note that, the drawings show the back surface (first surface 30A) side of the semiconductor substrate 30 as the light incident side S1 and the front surface (second surface 30B) side as the wiring layer side S2.

[0054] As described above, the organic photoelectric conversion section 20 has a configuration in which the lower electrode 21, the organic photoelectric conversion layer 22, and the upper electrode 23 are sequentially stacked from the first surface 30A side of the semiconductor substrate 30. The lower electrode 21 is formed, for example, for each photoelectric conversion element 10A. Figure 1 An example in which the organic photoelectric conversion layer 22 and the upper electrode 23 are provided as a continuous layer common to the unit pixels Pr, Pg, and Pb is shown, but like the lower electrode 21, the organic photoelectric conversion layer 22 and the upper electrode 23 can also be formed for each of the unit pixels Pr, Pg, and Pb.

[0055] An interlayer insulating layer 34 is provided, for example, between the first surface 30A of the semiconductor substrate 30 and the organic photoelectric conversion section 20. A color filter 51 is provided, for example, above the upper electrode 23. Although not shown, an optical member such as a planarization layer and an on-chip lens is provided, for example, above the color filter 51.

[0056] A through electrode 35 is provided between the first surface 30A and the second surface 30B of the semiconductor substrate 30. The lower electrode 21 is electrically connected to the charge holding section 33 through the through electrode 35. In other words, the through electrode 35 has a function as a connector for the organic photoelectric conversion section 20 and the charge holding section 33, and also functions as a transport path for signal charges generated in the organic photoelectric conversion section 20. Therefore, the photoelectric conversion element 10A is able to transport signal charges (here, electrons) generated by the organic photoelectric conversion section 20 on the first surface 30A side of the semiconductor substrate 30 to the second surface 30B side of the semiconductor substrate 30 through the through electrode 35 with excellent efficiency, and is able to improve characteristics. An insulating film 36 is provided, for example, around the through electrode 35. The through electrode 35 is electrically insulated from the p-well 31.

[0057] In the organic photoelectric conversion section 20 according to the present embodiment, light from the upper electrode 23 side is absorbed by the organic photoelectric conversion layer 22. Excitons generated thereby move to the interface between the electron donor and the electron acceptor included in the organic photoelectric conversion layer 22, and exciton separation is performed. In other words, the excitons dissociate into electrons and holes. The charges (electrons and holes) generated thereby are transported to different electrodes by diffusion caused by a difference in carrier concentration and an internal electric field caused by a difference in work function between the anode (here, the upper electrode 23) and the cathode (here, the lower electrode 21). The transported charges are detected as a photoelectric current. In addition, by applying a potential between the lower electrode 21 and the upper electrode 23, it is possible to control the transport direction of the electrons and holes.

[0058] The configuration and materials of each part and the like will be described below.

[0059] The organic photoelectric conversion unit 20 is an organic photoelectric conversion element that absorbs light corresponding to part or all of the wavelength range of the visible light region and generates electron-hole pairs.

[0060] The lower electrode 21 is used to attract electrons from the charge generated in the organic photoelectric conversion layer 22 as signal charges and transfer the attracted signal charges to the charge holding part 33. The lower electrode 21 includes a transparent conductive film. The lower electrode 21 includes, for example, ITO (indium tin oxide). However, in addition to ITO, tin oxide (SnO2) based materials with added dopants or zinc oxide based materials obtained by adding dopants to zinc oxide (ZnO) can also be used as materials included in the lower electrode 21. Examples of zinc oxide based materials include aluminum zinc oxide (AZO) with aluminum (Al) as a dopant, gallium zinc oxide (GZO) with gallium (Ga) added, and indium zinc oxide (IZO) with indium (In). In addition, CuI, InSbO4, ZnMgO, CuInO2, MgIN2O4, CdO, ZnSnO3, or TiO2 can be used as materials included in the lower electrode 21. Furthermore, spinel oxides or oxides having a YbFe2O4 structure can be used.

[0061] The organic photoelectric conversion layer 22 converts light energy into electrical energy. The organic photoelectric conversion layer 22 is formed comprising a fullerene C represented by the following formula (4). 60 Or fullerene C represented by the following formula (5) 70 And organic semiconductor materials with ionization potentials below 5.0 eV. It should be noted that, in cases where there is no need to specifically distinguish fullerenes (C1),... 60 and fullerene C 70 In this case, they are collectively referred to as fullerenes.

[0062] [Chemical Formula 1]

[0063]

[0064] Fullerenes absorb light in the blue region. Fullerenes exhibit high aggregation properties. Considering thermal vibrations, the Cg values ​​of five fullerenes were calculated using time-dependent density-functional theory (TDDFT). 60 The photoexcitation energy of the aggregates. Time-correlated density functional method (TDDFT) is one of the first-principles calculation techniques. This calculation provides... Figure 3 The energy spectrum is shown. As computational conditions, the functional is ωB97XD, the basis functions are 3-21G(d), and the number of excited states is S1 to S75 (up to the 75th singlet excited state). In fullerene C... 60molecules, excitons extending between a plurality of fullerene C 60 molecules are generated. The binding energy of the excitons is small. For this reason, the excitons are more likely to undergo charge separation than ordinary singlet excitons. In other words, photoelectric conversion is easier for the excitons than for the singlet excitons. Thus, the photoelectric conversion efficiency for light in the blue region can be improved.

[0065] Figure 3 It is shown that the energy of the doublet exciton is 0.3 eV higher on average than the energy of the singlet exciton, and the energy of the triplet exciton is 0.4 eV higher on average than the energy of the singlet exciton. Generally, a photoelectric conversion element has an energy difference (ΔΕ) of 0.3 eV to 0.4 eV at a p / n junction interface. In the case where the energy difference (ΔΕ) at the p / n junction interface is considered to be 0.35 eV on average, it is inferred that by generating an energy difference satisfying ΔE ≥ 0.05 eV in the organic photoelectric conversion layer 22 including a fullerene, the doublet exciton and the triplet exciton can be effectively subjected to charge separation.

[0066] An organic semiconductor material having an ionization potential of 5.0 eV or less is used to generate an energy difference satisfying ΔE ≥ 0.05 eV in the organic photoelectric conversion layer 22. The above-described organic semiconductor material having an ionization potential of 5.0 eV or less tends to become a cation in the organic photoelectric conversion layer 22. For example, as shown in FIG. 6, in a film including a fullerene C Figure 4 60 molecules, an energy difference (ΔΕ) of 0.18 eV is generated between the first proximity C Figure 5 60 and the second proximity C 60 . In other words, by doping the organic semiconductor material having an ionization potential of 5.0 eV or less, the doublet exciton and the triplet exciton extending between a plurality of fullerene C 60 molecules can be effectively subjected to charge separation in the organic photoelectric conversion layer 22.

[0067] Preferably, the amount of addition of the organic semiconductor material having an ionization potential of 5.0 eV or less is, for example, 2% or more and 10% or less of the volume density of the fullerenes contained in the organic photoelectric conversion layer 22. This is because in the case where the doping concentration is too high, the generation of the excitons in the fullerene aggregate is suppressed. Therefore, preferably, for example, in the case where the organic semiconductor material having an ionization potential of 5.0 eV or less is doped in the film including a fullerene C 60 60 molecules (the first proximity C 60 ​​​The addition amount of the organic semiconductor material having an ionization potential of 5.0 eV or less, which is the closest to the dopant, is 10% or less. On the contrary, in a case where the doping concentration is too low, it can be impossible to obtain sufficient photoelectric conversion efficiency. For example, in a case where the doping concentration is less than 2%, it is difficult to control the doping concentration from a processing point of view, and it is impossible to obtain stable characteristics. Therefore, the addition amount of the organic semiconductor material having an ionization potential of 5.0 eV or less is preferably 2% or more.

[0068] Examples of the organic semiconductor material having an ionization potential of 5.0 eV or less include a compound represented by the following general formula (1).

[0069] [Chemical Formula 2]

[0070]

[0071] (X represents any one of oxygen (O), sulfur (S), and selenium (Se); R1to R4each independently represent a methyl group, a thiomethyl group, a hexamethylene group, an octamethylene group, an ethylenedithio group, a methylenedithio group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenylnaphthyl group, a biphenylnaphthyl group, a binaphthyl group, a thiophenyl group, a bithiophenyl group, a terthiophenyl group, a benzothiophenyl group, a phenylbenzothiophenyl group, a biphenylbenzothiophenyl group, a benzofuranyl group, a phenylbenzofuranyl group, a biphenylbenzothiophenyl group, an alkane group, a cycloalkane group, a fluorenyl group, a phenylfluorenyl group, or a derivative thereof; R1to R4may form an aromatic or non-aromatic hydrocarbon ring or a heterocyclic ring or a polycyclic fused ring between two adjacent substituents; and the hydrocarbon ring, the heterocyclic ring, and the polycyclic fused ring each include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a benzophenanthrene ring, a tetracene 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, an indolizine ring, an indole ring, a benzofuran ring, a benzothiophene ring, an isobenzofuran ring, a quinolizine ring, a quinoline ring, a phthalazine ring, a naphthylidine 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 phenothiazine ring, or a phenoxazine ring.)

[0072] As specific examples of the compound represented by the above general formula (1), for example, there are included tetra-thiafulvalene and derivatives thereof represented by the following formulae (1-1) to (1-9). The tetra-thiafulvalene and derivatives thereof represented by these formulae (1-1) to (1-9) correspond to specific examples of the “second organic semiconductor material” according to the present disclosure.

[0073] [Chemical Formula 3]

[0074]

[0075] The organic photoelectric conversion layer 22 can also include an organic material or a so-called dye material that photoelectrically converts light in a predetermined wavelength band of the visible light region (e.g., 400 nm or more and 760 nm or less) and transmits light in other wavelength bands. This dye material corresponds to a specific example of the "third organic semiconductor material" according to the present disclosure.

[0076] Examples of the dye material include subphthalocyanine, dipyrromethene, merocyanine, or squarylium or a derivative thereof that absorbs light in a wavelength band of 500 nm or more and 600 nm or less. In addition, for example, any one of naphthalene, anthracene, phenanthrene, naphthacene, pyrene, perylene, and fluoranthene or a derivative thereof can be used as the dye material. Alternatively, a polymer such as phenylenevinylene, fluorene, carbazole, indole, pyrene, pyrrole, methylpyridine, thiophene, acetylene, or diacetylene or a derivative thereof can be used. Furthermore, it can be preferable to use a metal complex dye; a cyanine dye; a merocyanine dye; a phenylxanthene dye; a triphenylmethane dye; a rhodol dye; a xanthene dye; a macrocyclic azacycloalkene dye; an azacycloalkene dye; a naphthoquinone; an anthraquinone dye; a chain compound condensed with condensed polycyclic aromatic groups and aromatic or heterocyclic compounds such as anthracene and pyrene; or a cyanine dye obtained by bonding two nitrogen-containing heterocycles having a squarylium group and a croconic methylene group as a bonding chain (e.g., quinoline, benzothiophene, and benzoxazole) or a cyanine dye obtained by bonding a squarylium group and a croconic methylene group, and the like. Note that as the above metal complex dye, a dithiol metal complex dye, a metal phthalocyanine dye, a metal porphyrin dye, or a ruthenium complex dye is preferable, but is not limited thereto.

[0077] In this way, the organic photoelectric conversion layer 22 is formed using three kinds of organic semiconductor materials, namely, fullerene, an organic semiconductor material (dopant) having an ionization potential of 5.0 eV or less, and a dye material. Thus, light in the visible light region can be widely absorbed.

[0078] The organic photoelectric conversion layer 22 can also include an organic semiconductor material having a hole-transporting property. The organic semiconductor material having a hole-transporting property corresponds to a specific example of the "fourth organic semiconductor material" according to the present disclosure. Examples of the organic semiconductor material having a hole-transporting property include thiophene or a derivative thereof, anthracene or a derivative thereof, or naphthacene or a derivative thereof, and the like.

[0079] In a case where the organic photoelectric conversion layer 22 is formed using three kinds of organic semiconductor materials of the fullerene, the organic semiconductor material (dopant) having an ionization potential of 5.0 eV or less, and the organic semiconductor material having a hole transporting property, the fullerene and the organic semiconductor material having a hole transporting property form a bulk heterojunction structure as a p-type semiconductor and an n-type semiconductor in the layer of the organic photoelectric conversion layer 22. The bulk heterojunction structure is a p / n junction surface formed by mixing the p-type semiconductor and the n-type semiconductor, and excitons generated by absorbing light are separated into an electron and a hole at the p / n junction interface.

[0080] Note that the p-type semiconductor functions as an electron donor (donor) and the n-type semiconductor functions as an electron acceptor (acceptor) in a relative manner. The above-described organic semiconductor materials function as a p-type semiconductor or an n-type semiconductor depending on their combination.

[0081] The organic photoelectric conversion layer 22 can be formed using four kinds of organic semiconductor materials of the fullerene, the organic semiconductor material (dopant) having an ionization potential of 5.0 eV or less, the dye material, and the organic semiconductor material having a hole transporting property.

[0082] For example, the above-described various organic semiconductor materials are mixed, and the organic photoelectric conversion layer 22 can be formed using a vacuum evaporation method. Alternatively, for example, a spin coating technique or a printing technique can be used.

[0083] Like the lower electrode 21, the upper electrode 23 includes a conductive film having a light-transmitting property.

[0084] Other layers can be provided between the organic photoelectric conversion layer 22 and the lower electrode 21 and between the organic photoelectric conversion layer 22 and the upper electrode 23. Specifically, for example, an electron-blocking film, the organic photoelectric conversion layer 22, a hole-blocking film, and a work function adjustment layer, or the like can be sequentially stacked from the lower electrode 21 side. Further, a bottom layer and a hole-transporting layer can be provided between the lower electrode 21 and the organic photoelectric conversion layer 22, and a buffer layer and an electron-transporting layer can be provided between the organic photoelectric conversion layer 22 and the upper electrode 23.

[0085] The semiconductor substrate 30 includes, for example, an n-type silicon (Si) substrate, and includes a p-well 31 in a predetermined region.

[0086] The inorganic photoelectric conversion section 32 includes, for example, a PIN (Positive Intrinsic Negative) type photodiode PD, and has a pn junction in a predetermined region of the semiconductor substrate 30. The inorganic photoelectric conversion section 32 detects light (infrared light (IR)) in a partial or entire wavelength range of the infrared light region. The second surface 30B of the semiconductor substrate 30 is provided with pixel transistors such as a transfer transistor, an amplification transistor, and a reset transistor, in addition to the charge holding section 33.

[0087] The interlayer insulating layer 34 includes, for example, a single layer film including one of silicon oxide (SiO x ), TEOS, silicon nitride (SiN x ), and silicon oxynitride (SiON), or a laminated film including two or more of the above.

[0088] The through electrode 35 can be formed using, for example, a metal material such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf), and tantalum (Ta), in addition to a doped silicon material such as PDAS (Phosphorus Doped Amorphous Silicon).

[0089] The insulating film 36 serves to electrically separate the semiconductor substrate 30 and the through electrode 35. The insulating film 36 can be formed using, for example, silicon oxide (SiO x ), TEOS, silicon nitride (SiN x ), and silicon oxynitride (SiON), like the interlayer insulating layer 34.

[0090] (1-2. Configuration of the imaging device)

[0091] The imaging device 1 is, for example, a CMOS image sensor. The imaging device 1 receives incident light (image light) from a subject through an optical lens system (not shown). The imaging device 1 converts the amount of incident light formed as an image on an imaging surface into an electric signal in units of pixels, and outputs the electric signal as a pixel signal. The imaging device 1 includes a pixel section 100 serving as an imaging region on the semiconductor substrate 30. The imaging device 1 includes, for example, a vertical drive circuit 111, a column signal processing circuit 112, a horizontal drive circuit 113, an output circuit 114, a control circuit 115, and an input / output terminal 116 in a peripheral region of the pixel section 100.

[0092] The pixel section 100 includes a plurality of unit pixels P arranged two-dimensionally in a matrix form, for example. These unit pixels P are provided with a pixel drive line Lread (specifically, a row selection line and a reset control line) for each pixel row, and a vertical signal line Lsig for each pixel column. The pixel drive line Lread transmits a drive signal for reading out a signal from a pixel. One end of the pixel drive line Lread is connected to an output terminal of the vertical drive circuit 111 corresponding to each row.

[0093] The vertical drive circuit 111 includes a shift register and an address decoder, and the like, and is a pixel driver that drives each unit pixel P of the pixel section 100 in units of rows, for example. Signals output from each unit pixel P in a pixel row selectively scanned by the vertical drive circuit 111 are supplied to the column signal processing circuit 112 through each vertical signal line Lsig. Each column signal processing circuit 112 includes an amplifier and a horizontal selection switch provided for each vertical signal line Lsig, and the like.

[0094] The horizontal drive circuit 113 includes a shift register and an address decoder, and the like, and sequentially drives each horizontal selection switch of the column signal processing circuit 112 while scanning the horizontal selection switches. Through this selective scanning by the horizontal drive circuit 113, signals of each pixel transmitted through each vertical signal line Lsig are sequentially output to a horizontal signal line 121, and the signals are transmitted to the outside of the semiconductor substrate 30 through the horizontal signal line 121.

[0095] The output circuit 114 performs signal processing on signals sequentially supplied from each column signal processing circuit 112 through the horizontal signal line 121 and outputs the signals. The output circuit 114 performs only buffering in some cases, for example, and performs black level adjustment, column variation correction, and various digital signal processing, and the like, in other cases.

[0096] The circuit portions including the vertical drive circuit 111, the column signal processing circuit 112, the horizontal drive circuit 113, the horizontal signal line 121, and the output circuit 114 can be formed directly on the semiconductor substrate 30, or can be provided in an external control IC. In addition, those circuit portions can be formed in another substrate connected through a cable or the like.

[0097] The control circuit 115 receives a clock supplied from the outside of the semiconductor substrate 30, and data for an instruction regarding an operation mode, and the like, and also outputs data such as internal information of the imaging device 1. The control circuit 115 also includes a timing generator that generates various timing signals, and controls driving of peripheral circuits such as the vertical drive circuit 111, the column signal processing circuit 112, and the horizontal drive circuit 113, based on the various timing signals generated by the timing generator.

[0098] The input / output terminal 16 exchanges signals with the outside.

[0099] (1-3. Action and Effect)

[0100] In the photoelectric conversion element 10A according to the present embodiment and the imaging device 1 including the photoelectric conversion element 10A, fullerene C 60 or fullerene C 70 having an ionization potential of 5.0 eV or less represented by general formula (1) is used to form the organic photoelectric conversion layer 22. Therefore, a plurality of excitons generated in a fullerene aggregate formed in the layer of the organic photoelectric conversion layer 22 can be effectively subjected to charge separation. This will be described below.

[0101] In a CCD (Charge Coupled Device) image sensor and a CMOS image sensor, an image sensor using an organic photoelectric conversion film has been developed. For example, an imaging device using an organic photoelectric conversion film having a multilayer structure in which an organic photoelectric conversion film sensitive to blue light (B), an organic photoelectric conversion film sensitive to green light (G), and an organic photoelectric conversion film sensitive to red light (R) are sequentially stacked has been proposed. Such an image sensor achieves an improvement in sensitivity by extracting B / G / R signals from one pixel, respectively. In addition, an imaging device having a single-layer organic photoelectric conversion film stacked on a semiconductor substrate in which a photodiode is formed as an inorganic photoelectric conversion portion has been proposed. In this imaging device, a signal of one color is extracted by the organic photoelectric conversion film, and signals of two colors are extracted by a silicon (Si) body spectrum.

[0102] Incidentally, in recent years, there has been a demand for development of an image sensor capable of capturing an image obtained from visible light and infrared light (IR). For example, in the case of applying the above-described organic imaging device, a wider range of visible light region can be absorbed, but it is difficult to manufacture an imaging device having a commercial size in the related art.

[0103] Meanwhile, by using a single-layer organic photoelectric conversion film as a photoelectric conversion film for visible light, the sensitivity is improved.

[0104] In contrast, in the present embodiment, fullerene C 60 or fullerene C 70 having an ionization potential of 5.0 eV or less represented by general formula (1) is used to form the organic photoelectric conversion layer 22. Therefore, a plurality of excitons generated in a fullerene aggregate formed in the layer of the organic photoelectric conversion layer 22 can be effectively subjected to charge separation. In other words, fullerene can be used as a material that absorbs light in the blue region.

[0105] As described above, in the photoelectric conversion element 10A according to the present embodiment, the photoelectric conversion efficiency of the organic photoelectric conversion layer 22 for blue light can be improved. Therefore, by forming the organic photoelectric conversion layer 22, for example, together with an organic semiconductor material called a so-called dye material (for example, subphthalocyanine), photoelectric conversion can be performed for a wider visible light region. In other words, an imaging device having high sensitivity can be provided.

[0106] In addition, in the present embodiment, the composition of fullerene can be increased compared to the organic photoelectric conversion layer of a typical organic photoelectric conversion element. Therefore, the electron conductivity can be improved. Therefore, the signal charge generated in the organic photoelectric conversion layer 22 can be quickly transported to the lower electrode 21. Therefore, the image quality at the time of imaging can be improved.

[0107] Next, a second embodiment of the present disclosure and modified examples 1 and 2 will be described. Hereinafter, the same components as those of the above-described first embodiment are given the same symbols, and the description thereof will be appropriately omitted.

[0108] <2. Second Embodiment>

[0109] Figure 6 An example of the cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10B) according to the second embodiment of the present disclosure is shown. As with the photoelectric conversion element 10A according to the above-described first embodiment, one pixel (unit pixel P) in an imaging device 1 such as a CMOS image sensor used in an electronic device such as a digital camera or a video camera, for example, includes the photoelectric conversion element 10B. The organic photoelectric conversion layer 62 of the photoelectric conversion element 10B according to the present embodiment is formed using fullerene (fullerene C 60 or fullerene C 70 ) and an organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in the ground state or the excited state.

[0110] (2-1. Configuration of Photoelectric Conversion Element)

[0111] The photoelectric conversion element 10B has a configuration in which, for example, one organic photoelectric conversion section 60 and one inorganic photoelectric conversion section 32 are stacked in the vertical direction. The organic photoelectric conversion section 60 is an organic photoelectric conversion element that absorbs light corresponding to a part or all of the wavelength range of the visible light region and generates electron-hole pairs. The organic photoelectric conversion section 60 includes an organic photoelectric conversion layer 62 between a lower electrode 21 and an upper electrode 23 arranged opposite each other. The organic photoelectric conversion layer 62 is formed using the above-described organic semiconductor material as an organic material.

[0112] Similar to the organic semiconductor material with an ionization potential of 5.0 eV or less in the first embodiment described above, an organic semiconductor material with an electric dipole moment of 10 Debye or more and 30 Debye or less in the ground state or excited state is used to generate an energy difference satisfying ΔE ≥ 0.05 eV in the organic photoelectric conversion layer 22.

[0113] For example, such as Figure 7 As shown, in the presence of fullerene C 60 When a film is doped with an organic semiconductor material having an electric dipole moment of 10 Debye or more in the ground state or excited state (hereinafter, an organic semiconductor material having an electric dipole moment of 10 Debye or more in the ground state or excited state is referred to as a dopant), for example, such as Figure 8 and Figure 9 As shown, the first C near the dopant 60 The second closest to C 60 An energy difference (ΔE) of more than 0.05 eV is generated between them. In other words, it can enable multiple fullerene C2O4 cells to achieve this. 60 The extended doublet and triplet excitons between molecules are effectively charged in the organic photoelectric conversion layer 22.

[0114] It should be noted that organic semiconductor materials with an electric dipole moment greater than 30 Debye in the ground or excited state may exhibit low mobility due to carrier scattering. Therefore, it is preferable to include fullerene C 60 The organic semiconductor material doped with the film has an electric dipole moment of less than 30 Debye in the ground state or excited state.

[0115] Similar to the first embodiment described above, preferably, the amount of organic semiconductor material with an electric dipole moment of 10 Debye or more and 30 Debye or less in the ground state or excited state is, for example, 2% or more and 10% or less of the volume density of the fullerene contained in the organic photoelectric conversion layer 22. In cases where the doping concentration is too high, the generation of multiple excitons in the fullerene aggregates is suppressed. Therefore, preferably, for example, in the presence of fullerene C... 60 When the film is doped with organic semiconductor materials whose electric dipole moment is greater than 10 Debye and less than 30 Debye in the ground state or excited state, due to approximately ten fullerene C 60 Molecules (first closest to C) 60) 10% or less. On the contrary, in a case where the doping concentration is too low, it can be impossible to obtain sufficient photoelectric conversion efficiency. For example, in a case where the doping concentration is less than 2%, it is difficult to control the doping concentration from a processing perspective, and stable characteristics cannot be obtained. Therefore, preferably, the additive amount of the organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in the ground state or the excited state is 2% or more.

[0116] Examples of the organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in the ground state or the excited state include a cyanine-based compound having a parent skeleton represented by the following general formula (2) and including a substituent of any one of the following (A-1) to (A-6) at A and a substituent of any one of the following (B-1) to (B-6) at B.

[0117] [Chemical Formula 4]

[0118]

[0119] [Chemical Formula 5]

[0120]

[0121] [Chemical Formula 6]

[0122]

[0123] Further, examples of the organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in the ground state or the excited state include a compound represented by the following general formula (3).

[0124] [Chemical Formula 7]

[0125]

[0126] (R5to R7each independently represent a halogen atom, an alkyl group, an alkenyl 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 aryloxycarbonyl group, an amine group, an amino group, an amido 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 aromatic ring azo group, a heterocyclic ring azo group, a phosphonic acid group, a phosphine group, a phosphinyl group, a phosphine amine group, a phosphine group, a silicon group, a hydrazine group, a urea group, a boronic acid group (-B(OH)2), a sulfate group (-OSO3H), or a derivative thereof.)

[0127] Note that examples of the alkyl group include a cycloalkyl group, a bicycloalkyl group, or a tricycloalkyl group. Examples of the alkenyl group include a cycloalkenyl group or a bicycloalkenyl group. Examples of the amino group include an alkylamino group, an arylamino group, or a heterocyclic amino group.

[0128] As specific examples of the compound represented by General Formula (3) described above, for example, coumarin derivatives represented by the following Formulae (3-1) to (3-5) are included.

[0129] [Chemical Formula 8]

[0130]

[0131] The cyanine-based compound represented by General Formula (2) including any one of the above Formulae (A-1) to (A-6) and any one of the above Formulae (B-1) to (B-6) and the coumarin derivative represented by the above Formulae (3-1) to (3-5) correspond to specific examples of the "second organic semiconductor material" according to the present disclosure.

[0132] As with the organic photoelectric conversion layer 22 according to the above first embodiment, the organic photoelectric conversion layer 62 can further include an organic material or a so-called dye material that photoelectrically converts light in a predetermined wavelength band of the visible light region and transmits light in other wavelength bands. In addition, as with the organic photoelectric conversion layer 22 according to the above first embodiment, the organic photoelectric conversion layer 62 can further include an organic semiconductor material having a hole transport property.

[0133] For example, the various organic semiconductor materials described above are mixed and an organic photoelectric conversion layer 62 can be formed using a vacuum evaporation method. In addition, for example, a spin coating technique or a printing technique, or the like can be used.

[0134] (2-2. Action and Effect)

[0135] In the photoelectric conversion element 10B and the imaging device 1 including the photoelectric conversion element 10B according to the present embodiment, the organic photoelectric conversion layer 62 is formed by using a fullerene C 60 or a fullerene C 70 represented by Formula (5) and a cyanine-based compound represented by General Formula (2) or a coumarin derivative represented by any one of Formulas (3-1) to (3-5) described above, which has a dipole moment of 10 Debye or more and 30 Debye or less in a ground state or an excited state, and which includes, for example, any one of Formulas (A-1) to (A-6) and any one of Formulas (B-1) to (B-6). Therefore, a plurality of excitons generated in a fullerene aggregate formed in the layer of the organic photoelectric conversion layer 62 can be effectively subjected to charge separation, and the fullerene can be used as a material that absorbs light in a blue region, respectively.

[0136] As described above, in the photoelectric conversion element 10B according to the present embodiment, the photoelectric conversion efficiency of the organic photoelectric conversion layer 62 for blue light can be improved. Therefore, by forming the organic photoelectric conversion layer 62, for example, together with an organic semiconductor material called a so-called dye material (for example, subphthalocyanine), photoelectric conversion can be performed on a wider visible light region. In other words, an imaging device having high sensitivity can be provided.

[0137] In addition, in the present embodiment, the composition of the fullerene can be increased compared to the organic photoelectric conversion layer of a typical organic photoelectric conversion element. Therefore, the electron conductivity can be improved. Therefore, the signal charge generated in the organic photoelectric conversion layer 62 can be quickly transmitted to the lower electrode 21. Therefore, the image quality at the time of imaging can be improved.

[0138] <3. Modification>

[0139] (3-1. Modification 1)

[0140] Figure 10 An example of a cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10C) according to Modification 1 of the present disclosure is shown. The photoelectric conversion element 10A described in the above-described first embodiment can also be provided, for example, with a double band-pass filter 71 as a spectral adjustment layer.

[0141] The double band-pass filter 71 has a transmission band of a visible light region and an infrared light region, respectively. The double band-pass filter 71 is provided, for example, above the color filter 51.

[0142] Incidentally, similar to the first embodiment described above, when color filters 51R, 51G, and 51B and an organic photoelectric conversion unit 20 are disposed above the first surface 30A of the semiconductor substrate 30, which serves as the light incident surface, the infrared light absorbed by the inorganic photoelectric conversion units 32 of each of the unit pixels Pr, Pg, and Pb passes through the color filters 51R, 51G, and 51B and the organic photoelectric conversion unit 20. In other words, the infrared light absorbed by the inorganic photoelectric conversion units 32 of each of the unit pixels Pr, Pg, and Pb has different spectra. Therefore, the unit pixels Pr, Pg, and Pb have different sensitivities. This causes the problem that unit pixels Pr, Pg, and Pb cannot be used as IR pixels to generate the same infrared light image.

[0143] Therefore, in this modified example, by providing a dual bandpass filter 71, the infrared light detected by the inorganic photoelectric conversion unit 32 becomes light in the wavelength region of the transmission band of the dual bandpass filter 71 on the infrared light region side. Thus, unit pixels Pr, Pg, and Pb can detect infrared light with a uniform spectrum. Therefore, the photoelectric conversion element 10C can obtain an IR image in which IR signals obtained from all unit pixels Pr, Pg, and Pb arranged in a two-dimensional manner are used. Therefore, in addition to the effects of the first embodiment described above, an imaging device 1 capable of obtaining a high-resolution IR image can also be provided.

[0144] In addition, as a spectral adjustment layer, besides the dual bandpass filter 71, for example, such as Figure 11 As shown in the photoelectric conversion element 10D, a multilayer film filter 81 can also be used. In the multilayer film filter 81, for example, films comprising inorganic materials with high refractive indices and films comprising inorganic materials with low refractive indices are periodically and alternately stacked in a repetitive manner. Examples of inorganic materials with high refractive indices include silicon nitride (Si3N4) and titanium oxide (TiO2). Examples of inorganic materials with low refractive indices include silicon oxide (SiO2). For example, the multilayer film filter 81 can be disposed between the organic photoelectric conversion section 20 and the interlayer insulating layer 34.

[0145] Alternatively, for example, the same effect can be achieved by providing a plasma filter between the organic photoelectric conversion unit 20 and the semiconductor substrate 30.

[0146] (3-2. Variation Example 2)

[0147] Figure 12A cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10E) according to Modification 2 of the present disclosure is shown. One unit pixel P in an imaging device (imaging device 1), such as a CMOS image sensor, capable of capturing an image obtained from, for example, visible light includes the photoelectric conversion element 10E. The photoelectric conversion element 10E according to the present modification has a configuration in which a red photoelectric conversion section 90R, a green photoelectric conversion section 90G, and a blue photoelectric conversion section 90B are sequentially stacked on a semiconductor substrate 30 with an insulating layer 96 interposed therebetween.

[0148] The red photoelectric conversion section 90R, the green photoelectric conversion section 90G, and the blue photoelectric conversion section 90B each include an organic photoelectric conversion layer 92R, 92G, and 92B between a pair of electrodes. Specifically, the red photoelectric conversion section 90R, the green photoelectric conversion section 90G, and the blue photoelectric conversion section 90B each include the organic photoelectric conversion layer 92R, 92G, and 92B between a first electrode 91R and a second electrode 93R, between a first electrode 91G and a second electrode 93G, and between a first electrode 91B and a second electrode 93B, respectively.

[0149] On top of the blue photoelectric conversion section 90B, an on-chip lens 98L is provided with a protective layer 97 and a on-chip lens layer 98 interposed therebetween. A red charge accumulation layer 310R, a green charge accumulation layer 310G, and a blue charge accumulation layer 310B are provided in the semiconductor substrate 30. Light entering the on-chip lens 98L is photoelectrically converted by the red photoelectric conversion section 90R, the green photoelectric conversion section 90G, and the blue photoelectric conversion section 90B, and signal charges are transferred from the red photoelectric conversion section 90R to the red charge accumulation layer 310R, from the green photoelectric conversion section 90G to the green charge accumulation layer 310G, and from the blue photoelectric conversion section 90B to the blue charge accumulation layer 310B. Although the signal charges can be either electrons or holes generated by photoelectric conversion, the following description will be given assuming that the signal charges are electrons read out.

[0150] The semiconductor substrate 30 includes, for example, a p-type silicon substrate. The red charge accumulation layer 310R, the green charge accumulation layer 310G, and the blue charge accumulation layer 310B provided in the semiconductor substrate 30 each include an n-type semiconductor region, and signal charges (electrons) supplied from the red photoelectric conversion section 90R, the green photoelectric conversion section 90G, and the blue photoelectric conversion section 90B are accumulated in the n-type semiconductor regions. The n-type semiconductor regions of the red charge accumulation layer 310R, the green charge accumulation layer 310G, and the blue charge accumulation layer 310B are formed, for example, by doping an n-type impurity such as phosphorus (P) or arsenic (As) in the semiconductor substrate 30. Note that the semiconductor substrate 30 can be provided on a support substrate (not shown) including glass or the like.

[0151] Semiconductor substrate 30 includes a means for reading electrons from a red energy storage layer 310R, a green energy storage layer 310G, and a blue energy storage layer 310B, and for transmitting the read electrons, for example, to a vertical signal line. Figure 2 The pixel transistor has a vertical signal line (Lsig). A floating diffusion section of this pixel transistor is disposed in the semiconductor substrate 30 and is connected to the red energy storage layer 310R, the green energy storage layer 310G, and the blue energy storage layer 310B. The floating diffusion section includes an n-type semiconductor region.

[0152] Insulating layer 96 includes, for example, silicon oxide (SiO2). x ), silicon nitride (SiN) x ), silicon oxynitride (SiON) and hafnium oxide (HfO) x The insulating layer 96 may include various types of laminated insulating films. The insulating layer 96 may include organic insulating materials. The insulating layer 96 is provided with plugs and electrodes for connecting the red energy storage layer 310R and the red photoelectric conversion unit 90R, connecting the green energy storage layer 310G and the green photoelectric conversion unit 90G, and connecting the blue energy storage layer 310B and the blue photoelectric conversion unit 90B.

[0153] The red photoelectric conversion unit 90R, starting from the position near the semiconductor substrate 30, sequentially includes a first electrode 91R, an organic photoelectric conversion layer 92R, and a second electrode 93R. The green photoelectric conversion unit 90G, starting from the position near the red photoelectric conversion unit 90R, sequentially includes a first electrode 91G, an organic photoelectric conversion layer 92G, and a second electrode 93G. The blue photoelectric conversion unit 90B, starting from the position near the green photoelectric conversion unit 90G, sequentially includes a first electrode 91B, an organic photoelectric conversion layer 92B, and a second electrode 93B. An insulating layer 94 is provided between the red photoelectric conversion unit 90R and the green photoelectric conversion unit 90G. An insulating layer 95 is provided between the green photoelectric conversion unit 90G and the blue photoelectric conversion unit 90B. The red photoelectric conversion unit 90R, the green photoelectric conversion unit 90G, and the blue photoelectric conversion unit 90B selectively absorb red (e.g., wavelength 600 nm or more and 700 nm or less) light, green (e.g., wavelength 480 nm or more and 600 nm or less) light, and blue (e.g., wavelength 400 nm or more and 480 nm or less) light, respectively, and generate electron / hole pairs.

[0154] The first electrodes 91R, 91G, and 91B extract signal charges generated in the organic photoelectric conversion layers 92R, 92G, and 92B, respectively. The first electrodes 91R, 91G, and 91B are provided, for example, for each pixel. The first electrodes 91R, 91G, and 91B each include, for example, a light-transmissive conductive material. Specifically, the first electrodes 91R, 91G, and 91B each include ITO. The first electrodes 91R, 91G, and 91B each can include, for example, a tin oxide-based material or a zinc oxide-based material. The tin oxide-based material is obtained by adding a dopant to tin oxide. Examples of the zinc oxide-based material include aluminum zinc oxide in which aluminum is added as a dopant to zinc oxide; gallium zinc oxide in which gallium is added as a dopant to zinc oxide; and indium zinc oxide in which indium is added as a dopant to zinc oxide, and the like. In addition, IGZO, CuI, InSbO4, ZnMgO, CuInO2, MgIn2O4, CdO, ZnSnO3, and the like can be used.

[0155] For example, between the first electrode 91R and the organic photoelectric conversion layer 92R, between the first electrode 91G and the organic photoelectric conversion layer 92G, and between the first electrode 91B and the organic photoelectric conversion layer 92B, an electron transport layer can be provided. The electron transport layer functions to promote the supply of electrons generated in the organic photoelectric conversion layers 92R, 92G, and 92B to the first electrodes 91R, 91G, and 91B. The electron transport layer includes, for example, titanium oxide or zinc oxide, or the like, respectively. The electron transport layer can include laminated titanium oxide and zinc oxide, respectively.

[0156] The organic photoelectric conversion layers 92R, 92G, and 92B each absorb light in a selective wavelength range to perform photoelectric conversion, and transmit light in other wavelength ranges. Here, the light in the selective wavelength range is, for example, light in a wavelength range of 600 nm or more and 700 nm or less in the organic photoelectric conversion layer 92R, light in a wavelength range of 480 nm or more and 600 nm or less in the organic photoelectric conversion layer 92G, and light in a wavelength range of 400 nm or more and 480 nm or less in the organic photoelectric conversion layer 92B.

[0157] The organic photoelectric conversion layers 92R, 92G, and 92B each have the same configuration as that of the organic photoelectric conversion layer 12 according to the above-described embodiment. For example, the organic photoelectric conversion layers 92R, 92G, and 92B each include, for example, two or more kinds of organic semiconductor materials. Preferably, the organic photoelectric conversion layers 92R, 92G, and 92B each include, for example, either or both of a p-type semiconductor and an n-type semiconductor. For example, in the case where the organic photoelectric conversion layers 92R, 92G, and 92B each include two kinds of organic semiconductor materials, a p-type semiconductor and an n-type semiconductor, for example, one of the p-type semiconductor and the n-type semiconductor is preferably a material that transmits visible light, and the other is preferably a material that photoelectrically converts light in a selective wavelength range. Alternatively, preferably, the organic photoelectric conversion layers 92R, 92G, and 92B each include a material (a dye material) that photoelectrically converts light in a selective wavelength range, and three kinds of organic semiconductor materials of an n-type semiconductor and a p-type semiconductor that each transmit visible light.

[0158] For example, the organic photoelectric conversion layer 92R preferably uses, for example, a material (a dye material) that can photoelectrically convert light in a wavelength range of 600 nm or more and 700 nm or less. Examples of such a material include subnaphthalocyanine or a derivative thereof, and phthalocyanine or a derivative thereof. For example, the organic photoelectric conversion layer 92G preferably uses, for example, a material (a dye material) that can photoelectrically convert light in a wavelength range of 480 nm or more and 600 nm or less. Examples of such a material include subphthalocyanine or a derivative thereof, and the like. The organic photoelectric conversion layer 92B preferably uses, for example, a material (a dye material) that can photoelectrically convert light in a wavelength range of 400 nm or more and 480 nm or less. As such a material, fullerene (fullerene C 60 or fullerene C 70 ) formed as described above, an organic semiconductor material having an ionization potential of 5.0 eV or less, or an organic semiconductor material having a molecular dipole moment of 10 Debye or more and 30 Debye or less in a ground state or an excited state. In addition, the organic photoelectric conversion layer 92B can use, for example, a mixture of coumarin or a derivative thereof and porphyrin or a derivative thereof, in addition to the above-described materials.

[0159] For example, a hole-transporting layer can be provided between the organic photoelectric conversion layer 92R and the second electrode 93R, between the organic photoelectric conversion layer 92G and the second electrode 93G, and between the organic photoelectric conversion layer 92B and the second electrode 93B. The hole-transporting layer functions to facilitate the supply of holes generated in the organic photoelectric conversion layers 92R, 92G, and 92B to the second electrodes 93R, 93G, and 93B, respectively. The hole-transporting layer includes, for example, molybdenum oxide, nickel oxide, or vanadium oxide, or the like, respectively. The hole-transporting layer can include, for example, an organic material such as PEDOT (poly(3,4-ethylenedioxythiophene)) and TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine), or the like, respectively.

[0160] The second electrode 93R, the second electrode 93G, and the second electrode 93B function to extract holes generated in the organic photoelectric conversion layer 92R, holes generated in the organic photoelectric conversion layer 92G, and holes generated in the organic photoelectric conversion layer 92B, respectively. The holes extracted from the second electrodes 93R, 93G, and 93B are discharged to a p-type semiconductor region (not shown) in the semiconductor substrate 30, for example, through each transport path (not shown). The second electrodes 93R, 93G, and 93B include, for example, a conductive material such as gold, silver, copper, and aluminum, or the like, respectively. Like the first electrodes 91R, 91G, and 91B, the second electrodes 93R, 93G, and 93B can include a transparent conductive material, respectively. In the photoelectric conversion element 10E, holes are extracted from the second electrodes 93R, 93G, and 93B. For example, when a plurality of photoelectric conversion elements 10E are provided in the imaging device 1 described below, the second electrodes 93R, 93G, and 93B that are common to the respective photoelectric conversion elements 10E (unit pixels P) can be provided.

[0161] The insulating layer 94 functions to insulate the second electrode 93R and the first electrode 91G. The insulating layer 95 functions to insulate the second electrode 93G and the first electrode 91B. The insulating layers 94 and 95 include, for example, a metal oxide, a metal sulfide, or an organic substance, respectively. Examples of the metal oxide include silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, zinc oxide, tungsten oxide, magnesium oxide, niobium oxide, tin oxide, gallium oxide, and the like. Examples of the metal sulfide include zinc sulfide, magnesium sulfide, and the like. Preferably, the material included in each of the insulating layers 94 and 95 has a band gap of 3.0 eV or more.

[0162] As described above, the present technology is also applicable to a photoelectric conversion element (photoelectric conversion element 10E) in which a red photoelectric conversion section 90R, a green photoelectric conversion section 90G, and a blue photoelectric conversion section 90B are sequentially stacked. The red photoelectric conversion section 90R, the green photoelectric conversion section 90G, and the blue photoelectric conversion section 90B include a photoelectric conversion layer (organic photoelectric conversion layer 92R, 92G, and 92B), respectively. The photoelectric conversion layer (organic photoelectric conversion layer 92R, 92G, and 92B) includes an organic semiconductor material, respectively.

[0163] <4. Application Example>

[0164] The above-described imaging device 1 is applicable to any type of electronic equipment having an imaging function, such as a camera system such as a digital camera and a video camera, and a mobile phone having an imaging function, for example. Figure 13 A schematic configuration of an electronic equipment 1000 is shown.

[0165] The electronic equipment 1000 includes the imaging device 1, a DSP (Digital Signal Processor) circuit 1001, a frame memory 1002, a display unit 1003, a recording unit 1004, an operation unit 1005, and a power supply unit 1006. They are connected to each other through a bus 1007.

[0166] The DSP circuit 1001 is a signal processing circuit that processes a signal supplied from the imaging device 1. The DSP circuit 1001 outputs image data obtained by processing the signal from the imaging device 1. The frame memory 1002 temporarily retains the image data processed by the DSP circuit 1001 in units of frames.

[0167] The display unit 1003 includes, for example, a panel-type display device such as a liquid crystal panel or an organic EL (Electro Luminescence) panel, and records image data of a moving image or a still image captured by the imaging device 1 in a recording medium such as a semiconductor memory or a hard disk.

[0168] The operation unit 1005 outputs an operation signal of various functions of the electronic equipment 1000 according to an operation of a user. The power supply unit 1006 appropriately supplies various power sources for operations of the DSP circuit 1001, the frame memory 1002, the display unit 1003, the recording unit 1004, and the operation unit 1005 to these power supply targets.

[0169] <5. Application Example>

[0170] <Endoscope surgery system application example>

[0171] The technology according to the present disclosure (this technology) is applicable to various products. For example, the technology according to the present disclosure can be applied to an endoscope surgery system.

[0172] Figure 14 is a drawing showing an example of a schematic configuration of an endoscope surgery system to which the technology according to the embodiment of the present disclosure (this technology) is applicable.

[0173] In Figure 14In the present embodiment, a state in which a surgeon (doctor) 11131 performs surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000 is shown. As shown in the figure, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical tools 11110 such as a pneumoperitoneum tube 11111 and an energy device 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices used for endoscopic surgery are installed.

[0174] The endoscope 11100 includes a lens barrel 11101, a region of a predetermined length from a distal end of the lens barrel 11101 being inserted into a body cavity of the patient 11132, and a camera head 11102 connected to a proximal end of the lens barrel 11101. In the example shown, the endoscope 11100 is shown as being configured as a rigid endoscope having a rigid lens barrel 11101. However, the endoscope 11100 can also be configured as a flexible endoscope having a flexible lens barrel 11101.

[0175] An opening is provided at the distal end of the lens barrel 11101, and an objective lens is installed in the opening. A light source device 11203 is connected to the endoscope 11100 such that light generated by the light source device 11203 is guided to the distal end of the lens barrel 11101 by a light guide extending within the lens barrel 11101, and the light is irradiated onto an observation target in the body cavity of the patient 11132 via the objective lens. Note that the endoscope 11100 can be a forward-viewing endoscope, or can be an oblique-viewing endoscope or a side-viewing endoscope.

[0176] An optical system and an image pickup element are provided within the camera head 11102 such that reflected light (observation light) from the observation target is converged onto the image pickup element by the optical system. The observation light is photoelectrically converted by the image pickup element, and an electric signal corresponding to the observation light, i.e., an image signal corresponding to an observation image, is generated. This image signal is sent to a camera control unit (CCU) 11201 as raw data.

[0177] The CCU 11201 includes a central processing unit (CPU) or a graphics processing unit (GPU), and the CCU 11201 integrally controls the operation of the endoscope 11100 and a display device 11202. Further, the CCU 11201 receives the image signal from the camera head 11102, and performs various image processing such as development processing (demosaicing processing) for displaying an image based on the image signal, for example, on the image signal.

[0178] The display apparatus 11202 displays an image based on an image signal that is subjected to image processing by the CCU 11201 under the control of the CCU 11201.

[0179] The light source apparatus 11203 includes a light source such as a light emitting diode (LED) and supplies irradiation light to the endoscope 11100 when the surgical site is imaged, for example.

[0180] The input apparatus 11204 is an input interface of the endoscope surgery system 11000. The user can input various information or instructions to the endoscope surgery system 11000 through the input apparatus 11204. For example, the user inputs an instruction for changing the imaging conditions (type of irradiation light, magnification, or focal distance) of the endoscope 11100 or the like.

[0181] The treatment tool control apparatus 11205 controls the drive of the energy apparatus 11112 for cauterization or incision of tissue or closure of a blood vessel or the like. The pneumoperitoneum apparatus 11206 delivers gas into the body cavity of the patient 11132 through the pneumoperitoneum tube 11111 to inflate the body cavity, thereby securing the field of view of the endoscope 11100 and securing the working space of the surgeon. The recorder 11207 is an apparatus capable of recording various information related to surgery. The printer 11208 is an apparatus capable of printing various information related to surgery in various forms such as text, images, or charts.

[0182] Note that the light source apparatus 11203 that supplies irradiation light to the endoscope 11100 when the surgical site is imaged can include a white light source including, for example, an LED, a laser light source, or a combination of an LED and a laser light source. When the white light source includes a combination of red, green, and blue (RGB) laser light sources, since the output intensity and output timing of each color (each wavelength) can be controlled with high precision, the light source apparatus 11203 can adjust the white balance of the captured image. Further, in this case, if the observation object is irradiated with laser beams from each of the RGB laser light sources in a time-division manner, and the drive of the imaging element of the camera head 11102 is controlled in synchronization with the irradiation timing, images corresponding to the R, G, and B colors, respectively, can also be captured in a time-division manner. According to this method, even when no color filter is provided in the imaging element, a color image can be obtained.

[0183] Further, the light source apparatus 11203 can be controlled so that the light intensity to be output is changed every predetermined time. By controlling the drive of the imaging element of the camera head 11102 in synchronization with the timing of the light intensity change and acquiring images in a time-division manner, and then synthesizing the images, a high dynamic range image without black shadows of underexposure and highlights of overexposure can be generated.

[0184] Further, the light source device 11203 can be configured to supply light of a predetermined wavelength band prepared for special light observation. In the special light observation, for example, narrow band observation (narrow band imaging), that is, imaging of a predetermined tissue such as a blood vessel in a mucosal surface layer at high contrast, is performed by utilizing wavelength dependency of light absorption in a human tissue and irradiating light of a band narrower than a band of irradiation light (that is, white light) at the time of ordinary observation. Alternatively, in the special light observation, fluorescence observation that obtains an image by fluorescence generated by irradiation of excitation light can be performed. In the fluorescence observation, fluorescence from a human tissue (autofluorescence observation) can be observed by irradiating the human tissue with excitation light, or a fluorescent image can be obtained by locally injecting a reagent such as indocyanine green (ICG) into a human tissue and irradiating the human tissue with excitation light corresponding to a fluorescence wavelength of the reagent. As described above, the light source device 11203 can be configured to supply such narrow band light and / or excitation light suitable for special light observation.

[0185] Figure 15 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201. Figure 14 The camera head 11102 and the CCU 11201 are communicably connected to each other through a transmission cable 11400.

[0186] The camera head 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are communicably connected to each other through the transmission cable 11400.

[0187] The lens unit 11401 is an optical system provided at a position connected to the lens barrel 11101. The observation light taken in from the distal end of the lens barrel 11101 is guided to the camera head 11102 and is incident on the lens unit 11401. The lens unit 11401 includes a combination of a plurality of lenses including a zoom lens and a focus lens.

[0188] The number of imaging elements included in the imaging unit 11402 can be one (single board type) or a plurality (multi board type). For example, in a case where the imaging unit 11402 is configured as a multi board type, image signals respectively corresponding to R, G, and B are generated by the respective imaging elements, and these image signals can be synthesized to obtain a color image. The imaging unit 11402 can also be configured to have a pair of imaging elements to respectively acquire right eye image signals and left eye image signals ready for three-dimensional (3D) display. If 3D display is performed, the surgeon 11131 is able to more accurately grasp the depth of living tissue in a surgical site. Note that in a case where the imaging unit 11402 is configured as a stereo type, a system in which a plurality of lens units 11401 are provided corresponding to the respective imaging elements.

[0189] Further, the imaging unit 11402 is not necessarily provided on the camera head 11102. For example, the imaging unit 11402 can be provided just behind the objective lens inside the lens barrel 11101.

[0190] The drive unit 11403 includes an actuator, and under the control of the camera head control unit 11405, the drive unit 11403 moves the zoom lens and the focus lens of the lens unit 11401 along the optical axis by a predetermined distance. Thus, the magnification and the focus of the image taken by the imaging unit 11402 can be appropriately adjusted.

[0191] The communication unit 11404 includes a communication device for transmitting and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 as raw data through the transmission cable 11400.

[0192] In addition, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201, and supplies the control signal to the camera head control unit 11405. For example, the control signal includes information related to the imaging conditions, such as information that specifies the frame rate of the taken image, information that specifies the exposure value at the time of imaging, and / or information that specifies the magnification and the focus of the taken image.

[0193] Note that the imaging conditions such as the frame rate, the exposure value, the magnification, or the focus can be specified by the user, or can be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 includes an auto exposure (AE) function, an auto focus (AF) function, and an auto white balance (AWB) function.

[0194] The camera control unit 11405 controls the driving of the camera 11102 on the basis of a control signal from the CCU 11201 received through the communication unit 11404.

[0195] The communication unit 11411 includes a communication device for transmitting and receiving various information to and from the camera 11102. The communication unit 11411 receives an image signal transmitted from the camera 11102 through the transmission cable 11400.

[0196] Further, the communication unit 11411 transmits a control signal for controlling the driving of the camera 11102 to the camera 11102. The image signal and the control signal can be transmitted through electric communication or optical communication, or the like.

[0197] The image processing unit 11412 performs various image processing on an image signal in the form of raw data transmitted from the camera 11102.

[0198] The control unit 11413 performs various controls related to imaging of a surgical site or the like through the endoscope 11100 and display of a captured image obtained by imaging the surgical site or the like. For example, the control unit 11413 generates a control signal for controlling the driving of the camera 11102.

[0199] Further, on the basis of an image signal that has been subjected to image processing by the image processing unit 11412, the control unit 11413 controls the display device 11202 to display a captured image of the surgical site or the like. At this time, the control unit 11413 can recognize various objects in the captured image using various image recognition techniques. For example, the control unit 11413 can recognize a surgical tool such as forceps, a specific living body site, bleeding, and mist when the energy device 11112 is used, by detecting the shape and color of the edge of an object included in the captured image. When the control unit 11413 controls the display device 11202 to display the captured image, the control unit 11413 can display various pieces of surgery assistance information in a manner superimposed on the image of the surgical site using the recognition result. When the surgery assistance information is displayed in a superimposed manner and presented to the surgeon 11131, the burden on the surgeon 11131 can be reduced, and the surgeon 11131 can reliably perform surgery.

[0200] The transmission cable 11400 that connects the camera 11102 and the CCU 11201 is an electric signal cable prepared for electric signal communication, an optical fiber prepared for optical communication, or a composite cable prepared for electric communication and optical communication.

[0201] Here, in the example shown, although communication is performed via wired communication using transmission cable 11400, communication between camera 11102 and CCU 11201 can also be performed via wireless communication.

[0202] The examples of endoscopic surgical systems to which the technology according to this disclosure is applicable have been described above. The technology according to this disclosure is applicable to the imaging unit 11402 in the aforementioned components. By applying the technology according to this disclosure to the imaging unit 11402, detection accuracy is improved.

[0203] It should be noted that this explanation uses an endoscopic surgical system as an example, but the technology disclosed herein can also be applied to, for example, microsurgical systems.

[0204] <Examples of applications of moving objects>

[0205] The technology disclosed herein is applicable to a variety of products. For example, the technology disclosed herein can be implemented as a device mounted on any type of mobile body, such as: automobiles, electric vehicles, hybrid vehicles, motorcycles, bicycles, personal mobile devices, airplanes, drones, ships, robots, construction machinery, or agricultural machinery (tractors).

[0206] Figure 16 This is a block diagram illustrating a schematic construction example of a vehicle control system, which is an example of a mobile body control system to which the technology is applicable according to embodiments of the present disclosure.

[0207] The vehicle control system 12000 includes multiple electronic control units interconnected via a communication network 12001. Figure 16 In the example shown, the vehicle control system 12000 includes: a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. Furthermore, as part of the functional configuration of the integrated control unit 12050, a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown.

[0208] The drive system control unit 12010 controls the operation of equipment related to the vehicle's drive system according to various programs. For example, the drive system control unit 12010 serves as a control device for the following devices: drive force generating devices for generating the vehicle's driving force, such as an internal combustion engine or drive motor; drive force transmission mechanisms for transmitting the driving force to the wheels; steering mechanisms for adjusting the vehicle's steering angle; and braking devices for generating the vehicle's braking force.

[0209] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body in accordance with various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, tail lamps, brake lamps, turn signals, or fog lamps. In this case, radio waves transmitted from a mobile device that substitutes for a key or signals of various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these input radio waves or signals and controls a door lock device, a power window device, or lamps of the vehicle.

[0210] The outside -vehicle information detecting unit 12030 detects information outside the vehicle including the vehicle control system 12000. For example, the outside-vehicle information detecting unit 12030 is connected with an imaging section 12031. The outside-vehicle information detecting unit 12030 causes the imaging section 12031 to capture an image of the outside of the vehicle and receives the captured image. From the received image, the outside-vehicle information detecting unit 12030 can execute a detection process or a distance detection process on an object such as a pedestrian, a vehicle, an obstacle, a sign, or a letter on a road surface.

[0211] The imaging section 12031 is an optical sensor that receives light and outputs an electric signal corresponding to the amount of received light. The imaging section 12031 can output the electric signal as an image or can output the electric signal as ranging information. Further, the light received by the imaging section 12031 can be visible light or can be non-visible light such as infrared rays.

[0212] The in-vehicle information detecting unit 12040 detects information inside the vehicle. For example, the in-vehicle information detecting unit 12040 is connected with a driver state detecting section 12041 that detects the state of a driver. For example, the driver state detecting section 12041 includes a camera that images the driver. Based on detection information input from the driver state detecting section 12041, the in-vehicle information detecting unit 12040 can calculate the degree of fatigue or the degree of concentration of the driver or can determine whether the driver is dozing off.

[0213] Based on information outside or inside the vehicle acquired by the outside-vehicle information detecting unit 12030 or the in-vehicle information detecting unit 12040, the microcomputer 12051 can calculate a control target value of a driving force generating device, a steering mechanism, or a braking device, and can output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control for realizing an advanced driver assistance system (ADAS) function including collision avoidance or impact mitigation of the vehicle, follow-up travel based on a following distance, vehicle speed maintenance travel, vehicle collision warning, or lane deviation warning of the vehicle, or the like.

[0214] Further, the microcomputer 12051 can control a driving force generating device, a steering mechanism, or a braking device, or the like, based on information outside or inside the vehicle acquired by the outside-vehicle information detecting unit 12030 or the in-vehicle information detecting unit 12040, thereby performing cooperative control for realizing autonomous driving of the vehicle independently of the operation of the driver, or the like.

[0215] In addition, based on information outside the vehicle acquired by the outside-vehicle information detecting unit 12030, the microcomputer 12051 can output a control command to the body system control unit 12020. For example, the microcomputer 12051 controls a headlamp and switches a high beam to a low beam for preventing glare, for example, in accordance with the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detecting unit 12030, thereby performing cooperative control for preventing glare.

[0216] The sound / image output section 12052 transmits an output signal of at least one of a sound and an image to an output device capable of visually or aurally notifying a passenger on the vehicle or outside the vehicle of information. In Figure 16 Examples, an audio speaker 12061, a display section 12062, and an instrument panel 12063 are shown as the output device. The display section 12062 can include at least one of a vehicle-mounted display and a head-up display, for example.

[0217] Figure 17 is a view showing an example of a mounting position of the imaging section 12031.

[0218] In Figure 17 , the imaging section 12031 includes imaging sections 12101, 12102, 12103, 12104, and 12105.

[0219] For example, the imaging sections 12101, 12102, 12103, 12104, and 12105 are provided at positions of a front nose, a rearview mirror, a rear bumper, and a rear door of the vehicle 12100 and a position of an upper portion of a windshield inside the vehicle. The imaging section 12101 provided at the front nose and the imaging section 12105 provided at the upper portion of the windshield inside the vehicle mainly acquire images of a front of the vehicle 12100. The imaging sections 12102 and 12103 provided at the rearview mirror mainly acquire images of sides of the vehicle 12100. The imaging section 12104 provided at the rear bumper or the rear door mainly acquires an image of a rear of the vehicle 12100. The imaging section 12105 provided at the upper portion of the windshield inside the vehicle is mainly used for detecting a preceding vehicle, a pedestrian, an obstacle, a traffic signal, a traffic sign, or a lane.

[0220] Incidentally, Figure 17 Examples of imaging ranges of the imaging sections 12101 to 12104 are shown. The imaging range 12111 indicates an imaging range of the imaging section 12101 provided at the front nose. The imaging ranges 12112 and 12113 indicate imaging ranges of the imaging sections 12102 and 12103 provided at the rearview mirror, respectively. The imaging range 12114 indicates an imaging range of the imaging section 12104 provided at the rear bumper or the rear door. For example, a bird's-eye image of the vehicle 12100 when viewed from above is obtained by superimposing image data captured by the imaging sections 12101 to 12104.

[0221] At least one of the imaging sections 12101 to 12104 can have a function of acquiring distance information. For example, at least one of the imaging sections 12101 to 12104 can be a stereo camera composed of a plurality of imaging elements, or can be an imaging element having pixels for phase difference detection.

[0222] For example, the microcomputer 12051 can determine distances to respective three-dimensional objects within the imaging ranges 12111 to 12114 and changes in the distances over time (relative speeds with respect to the vehicle 12100) on the basis of distance information obtained from the imaging sections 12101 to 12104, and thereby extract a three-dimensional object closest to the vehicle 12100 and traveling in almost the same direction as the vehicle 12100 at a predetermined speed (for example, greater than or equal to 0 km / h) on a travel road as a preceding vehicle. In addition, the microcomputer 12051 can set a following distance to be maintained in front of the preceding vehicle in advance, and can perform automatic brake control (including follow-up stop control) or automatic acceleration control (including follow-up start control), and the like. Thus, cooperative control aimed at autonomous driving of the vehicle without depending on an operation of a driver or the like can be performed.

[0223] For example, the microcomputer 12051 can classify three-dimensional object data on three-dimensional objects into three-dimensional object data on a two-wheeled vehicle, a standard vehicle, a large vehicle, a pedestrian, a utility pole, and other three-dimensional objects on the basis of distance information obtained from the imaging sections 12101 to 12104, extract the classified three-dimensional object data, and use the extracted three-dimensional object data to automatically avoid obstacles. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that can be visually recognized by a driver of the vehicle 12100 and obstacles that are difficult to be visually recognized. Then, the microcomputer 12051 determines a collision risk indicating a risk of collision with each obstacle. In a case where the collision risk is equal to or higher than a set value and thus a collision is likely to occur, the microcomputer 12051 outputs a warning to the driver through the audio speaker 12061 or the display section 12062 and performs forced deceleration or avoidance steering via the drive system control unit 12010. Thus, the microcomputer 12051 can assist driving to avoid a collision.

[0224] At least one of the imaging sections 12101 to 12104 can be an infrared camera for detecting infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether the pedestrian is present in an image captured by the imaging sections 12101 to 12104. For example, recognition of such a pedestrian is performed by extracting feature points in an image captured by the imaging sections 12101 to 12104 as infrared cameras and determining whether an object represented by a series of the feature points is a pedestrian by pattern matching processing. When the microcomputer 12051 determines that a pedestrian is present in an image captured by the imaging sections 12101 to 12104 and thus recognizes the pedestrian, the sound / image output section 12052 controls the display section 12062 so that a rectangular outline line for emphasis is superimposed and displayed on the recognized pedestrian. The sound / image output section 12052 can also control the display section 12062 so that an icon or the like representing the pedestrian is displayed at a desired position.

[0225] Although the disclosure has been described with reference to the first and second embodiments, modified examples 1 and 2, application examples, and application examples, the disclosure is not limited to the above-described embodiments and the like. The disclosure can be modified in various ways. For example, the components, arrangement, and number of the photoelectric conversion element 10A and the like exemplified in the above-described embodiments and the like are merely examples. Not all of the components must be provided. In addition, other components can also be included.

[0226] In each of the above-described embodiments and the like, an example in which the organic photoelectric conversion section 20 that detects a visible light region and the inorganic photoelectric conversion section 32 that detects light in an infrared light region are layered has been described, but the organic photoelectric conversion section 20 can be used alone.

[0227] In addition, in each of the above embodiments and the like, an example in which the lower electrode 21 includes one electrode has been described, but two or more electrodes can also be used. Furthermore, in each of the above embodiments and the like, the present technology has been described with reference to an example of a so-called backside-illumination-type image sensor in which the multilayer wiring layer 40 is provided on the front surface (second surface 30B) side of the semiconductor substrate 30 and light is incident from the back surface (first surface 30A) side, but the present technology is also applicable to a frontside-illumination-type image sensor.

[0228] In addition, in the above modification example, an example in which each organic photoelectric conversion section (red photoelectric conversion section 90R, green photoelectric conversion section 90G, and blue photoelectric conversion section 90B) that detects red light (R), green light (G), and blue light (B), respectively, is stacked has been described, but is not limited thereto. For example, two organic photoelectric conversion sections of an organic photoelectric conversion section that detects blue light (B) and organic photoelectric conversion sections that detect red light (R) and green light (G) can be stacked. For example, red light (R) and green light (G) can be detected in the semiconductor substrate 30, and an organic photoelectric conversion section that detects blue light (B) can be provided above the semiconductor substrate 30. For example, red light (R) can be detected in the semiconductor substrate 30, and two organic photoelectric conversion sections that detect green light (G) and blue light (B), respectively, can be provided above the semiconductor substrate 30. The technology described in any one of the above first embodiment and second embodiment is applicable to the organic photoelectric conversion section that detects blue light (B).

[0229] Note that the effects described here are merely examples and are not limiting. Additionally, other effects can also be included.

[0230] Note that the present disclosure can also have the following configuration. According to the present technology having the following configuration, by using fullerene C 60 or fullerene C 70 and an organic semiconductor material having an ionization potential of 0 eV or more and 5.0 eV or less or an organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in a ground state or an excited state, a photoelectric conversion layer is formed. Thus, a plurality of excitons generated in a fullerene aggregate can be effectively subjected to charge separation. Thus, sensitivity to blue light can be improved, in particular. [1]

[0232] A photoelectric conversion element includes:

[0233] a first electrode;

[0234] a second electrode disposed opposite the first electrode; and

[0235] a photoelectric conversion layer provided between the first electrode and the second electrode, the photoelectric conversion layer containing, as a first organic semiconductor material, fullerene C 60 or fullerene C 70 and a second organic semiconductor material having an ionization potential of 0 or more and 5.0 eV or less. [2]

[0237] The photoelectric conversion element according to [1], wherein the second organic semiconductor material contained in the photoelectric conversion layer is contained in a range of 2% or more and 10% or less of a volume density of the first organic semiconductor material contained in the photoelectric conversion layer. [3]

[0239] The photoelectric conversion element according to [1] or [2], wherein the second organic semiconductor material contains a compound represented by the following general formula (1).

[0240] [Chemical Formula 1]

[0241]

[0242] (X represents any one of oxygen (O), sulfur (S), and selenium (Se); R1to R4each independently represent a methyl group, a thiomethyl group, a hexamethylene group, an octamethylene group, an ethylenedithio group, a methylenedithio group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenylnaphthyl group, a biphenylnaphthyl group, a binaphthyl group, a thiophenyl group, a bithiophenyl group, a terthiophenyl group, a benzothiophenyl group, a phenylbenzothiophenyl group, a biphenylbenzothiophenyl group, a benzofuranyl group, a phenylbenzofuranyl group, a biphenylbenzothiophenyl group, an alkane group, a cycloalkane group, a fluorenyl group, a phenylfluorenyl group, or a derivative thereof; R1to R4may form an aromatic or non-aromatic hydrocarbon ring or a heterocyclic ring or a polycyclic fused ring between two adjacent substituents; and the hydrocarbon ring, the heterocyclic ring, and the polycyclic fused ring each include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a benzophenanthrene ring, a tetracene 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, an indolizine ring, an indole ring, a benzofuran ring, a benzothiophene ring, an isobenzofuran ring, a quinolizine ring, a quinoline ring, a phthalazine ring, a naphthylidine 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 phenothiazine ring, or a phenoxazine ring.) [4]

[0244] The photoelectric conversion element according to [3], wherein the compound represented by general formula (1) includes any one of tetrafulvalene and derivatives thereof represented by the following formulae (1-1) to (1-9).

[0245] [Chemical Formula 2]

[0246] [5]

[0248] The photoelectric conversion element according to any one of [1] to [4], wherein the photoelectric conversion layer further includes a third organic semiconductor material. [6]

[0250] The photoelectric conversion element according to [5], wherein the third organic semiconductor material has absorbency in a wavelength range of 400 nm or more and 760 nm or less. [7]

[0252] The photoelectric conversion element according to any one of [1] to [6], wherein the photoelectric conversion layer further includes a fourth organic semiconductor material. [8]

[0254] The photoelectric conversion element according to [7], wherein the fourth organic semiconductor material has hole-transporting property. [9]

[0256] A photoelectric conversion element including:

[0257] a first electrode;

[0258] a second electrode disposed opposite to the first electrode; and

[0259] a photoelectric conversion layer provided between the first electrode and the second electrode, the photoelectric conversion layer containing, as a first organic semiconductor material, fullerene C 60 or fullerene C 70 and a second organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in a ground state or an excited state.

[10]

[0261] The photoelectric conversion element according to [9], wherein the second organic semiconductor material contained in the photoelectric conversion layer is contained in a range of 2% or more and 10% or less of a volume density of the first organic semiconductor material contained in the photoelectric conversion layer.

[11]

[0263] The photoelectric conversion element according to [9] or

[10] , wherein the second organic semiconductor material contains a cyanine-based compound having a parent skeleton represented by the following formula (2) and including, at A, a substituent of any one of the following (A-1) to (A-6) and, at B, a substituent of any one of the following (B-1) to (B-6).

[0264] [Chemical Formula 3]

[0265]

[12]

[0267] The photoelectric conversion element according to any one of [9] to

[11] , wherein the second organic semiconductor material includes a compound represented by the following general formula (3).

[0268] [Chemical Formula 4]

[0269]

[0270] (R5to R7each independently represent a halogen atom, an alkyl group, an alkenyl 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 aryloxycarbonyl group, an amine group, an amino group, an amido 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 aromatic ring azo group, a heterocyclic ring azo group, a phosphonic acid group, a phosphine group, a phosphineoxy group, a phosphineamino group, a phosphine group, a silicon group, a hydrazine group, a urea group, a boronic acid group (-B(OH)2), a sulfate group (-OSO3H), or a derivative thereof.)

[13]

[0272] The photoelectric conversion element according to

[12] , wherein the compound represented by the general formula (3) includes a coumarin derivative represented by the following formulae (3-1) to (3-5).

[0273] [Chemical Formula 5]

[0274]

[14]

[0276] An imaging device including:

[0277] a plurality of pixels each provided with one or more photoelectric conversion elements, wherein

[0278] the photoelectric conversion element includes:

[0279] a first electrode;

[0280] a second electrode disposed opposite to the first electrode; and

[0281] a photoelectric conversion layer disposed between the first electrode and the second electrode, the photoelectric conversion layer containing fullerene C 60 or fullerene C 70and a second organic semiconductor material having an ionization potential of 0 or more and 5.0 eV or less.

[15]

[0283] An imaging device including:

[0284] a plurality of pixels each provided with one or more photoelectric conversion elements,

[0285] the photoelectric conversion elements each include:

[0286] a first electrode;

[0287] a second electrode disposed opposite the first electrode; and

[0288] a photoelectric conversion layer disposed between the first electrode and the second electrode, the photoelectric conversion layer containing fullerene C 60 or fullerene C 70 and a second organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in a ground state or an excited state.

[0289] This application claims priority to Japanese Patent Application No. 2019-198481 filed October 31, 2019 with the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0290] Those skilled in the art will understand that various modifications, combinations, sub-combinations and changes can be made to the present application, depending on design requirements and other factors, without departing from the scope of the appended claims or equivalents thereof.

Claims

1. A photoelectric conversion element, comprising: First electrode; The second electrode is arranged opposite to the first electrode; A photoelectric conversion layer is disposed between the first electrode and the second electrode, the photoelectric conversion layer comprising a fullerene C as a first organic semiconductor material. 60 or fullerene C 70 And a second organic semiconductor material with an ionization potential of 0 or higher and 5.0 eV or lower; and A multilayer film filter is disposed below the first electrode. In the multilayer film filter, a film comprising a first inorganic material having a first refractive index and a film comprising a second inorganic material having a second refractive index are periodically and alternately stacked in a repetitive manner, wherein the first refractive index is higher than the second refractive index.

2. The photoelectric conversion element according to claim 1, wherein, The second organic semiconductor material included in the photoelectric conversion layer is in the range of 2% to 10% of the volume density of the first organic semiconductor material included in the photoelectric conversion layer.

3. The photoelectric conversion element according to claim 1 or 2, wherein, The second organic semiconductor material comprises a compound represented by the following general formula (1), [Chemical Formula 1] X represents any one of oxygen (O), sulfur (S), and selenium (Se); R1 to R4 each independently represent methyl, thiomethyl, hexamethylene, octamethylene, ethylene dithio, methylene dithio, phenyl, biphenyl, terphenyl, naphthyl, phenylnaphthyl, biphenylnaphthyl, biphenylnaphthyl, thienyl, bithienyl, terthienyl, benzothienyl, phenylbenzothienyl, biphenylbenzothienyl, benzofuranyl, phenylbenzofuranyl, biphenylbenzothienyl, alkaneyl, cycloalkaneyl, fluorenyl, phenylfluorenyl, or derivatives thereof; R1 to R4 may form an aromatic or non-aromatic compound between two adjacent substituents. Aromatic hydrocarbon rings, heterocycles, or polycyclic fused rings; and each of the hydrocarbon rings, heterocycles, and polycyclic fused rings includes a benzene ring, a naphthyl ring, anthracene ring, a phenanthrene ring, a fluorene ring, a benzo[a]phenanthrene ring, a tetraphenylene 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, an pyridazine ring, an indoleazine ring, an indole ring, a benzo[a]furan ring, a benzo[a]thiophene ring, an isobenzo[a]furan ring, a quinazine ring, a quinoline ring, a phthalazine ring, a naphthidine ring, a quinoxaline ring, a quinoxalazine ring, an isoquinoline ring, a carbazole ring, a phenanthridine ring, an acridine ring, a phenanthrene ring, a thiamethoxam ring, or a phenazine ring.

4. The photoelectric conversion element according to claim 3, wherein, The compounds represented by the general formula (1) include any one of the tetrathiofulvalenes and their derivatives represented by formulas (1-1) to (1-8). [Chemical Formula 2] 5. The photoelectric conversion element according to claim 1 or 2, wherein, The photoelectric conversion layer also includes a third organic semiconductor material.

6. The photoelectric conversion element according to claim 5, wherein, The third organic semiconductor material has absorption properties in the wavelength range above 400 nm and below 760 nm.

7. The photoelectric conversion element according to claim 1 or 2, wherein, The photoelectric conversion layer also includes a fourth organic semiconductor material.

8. The photoelectric conversion element according to claim 7, wherein, The fourth organic semiconductor material has hole transport properties.

9. A photoelectric conversion element, comprising: First electrode; The second electrode is arranged opposite to the first electrode; A photoelectric conversion layer is disposed between the first electrode and the second electrode, the photoelectric conversion layer comprising a fullerene C as a first organic semiconductor material. 60 or fullerene C 70 and a second organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in the ground state or excited state; and A multilayer film filter is disposed below the first electrode. In the multilayer film filter, a film comprising a first inorganic material having a first refractive index and a film comprising a second inorganic material having a second refractive index are periodically and alternately stacked in a repetitive manner, wherein the first refractive index is higher than the second refractive index.

10. The photoelectric conversion element according to claim 9, wherein, The second organic semiconductor material included in the photoelectric conversion layer is in the range of 2% to 10% of the volume density of the first organic semiconductor material included in the photoelectric conversion layer.

11. The photoelectric conversion element according to claim 9 or 10, wherein, The second organic semiconductor material includes anthocyanin compounds having a parent skeleton represented by the following formula (2) and including a substituent at A of any one of (A-1) to (A-6) below, and a substituent at B of any one of (B-1) to (B-6) below. [Chemical Formula 3] 12. The photoelectric conversion element according to claim 9 or 10, wherein, The second organic semiconductor material comprises a compound represented by the following general formula (3), [Chemical Formula 4] R5 to R7 each independently represent a halogen atom, alkyl, alkenyl, alkynyl, aryl, heterocyclic, cyano, hydroxyl, nitro, carboxyl, alkoxy, aryloxy, silyloxy, heterocyclic, acyloxy, carbamoyloxy, alkoxycarbonyloxy, aryloxycarbonyl, amino, amino, amide, aminocarbonylamino, alkoxycarbonylamino, aryloxycarbonylamino, aminosulfonylamino, alkylsulfonylamino, arylsulfonylamino, mercapto, alkylthio, arylthio, heterocyclic thio, aminosulfonyl, sulfonyl, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, acyl, aryloxycarbonyl, alkoxycarbonyl, carbamoyl, arylcyclic azo, heterocyclic azo, phosphonic acid, phosphonyl, phosphonoxy, phosphonoamino, phosphonyl, silyl, hydrazyl, urea, borate (-B(OH)2), sulfate (-OSO3H) or their derivatives.

13. The photoelectric conversion element according to claim 12, wherein, Compounds represented by the general formula (3) include coumarin derivatives represented by formulas (3-1) to (3-5). [Chemical Formula 5] 14. A camera device comprising: Multiple pixels, each pixel being provided with one or more photoelectric conversion elements, wherein, The photoelectric conversion element is the photoelectric conversion element according to any one of claims 1-13.

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