Photoelectric conversion element and image pickup element

Abstract

A first photoelectric conversion element of one embodiment of the present disclosure includes: a first electrode; a second electrode that is disposed so as to face the first electrode; and a photoelectric conversion layer, which is provided between the first electrode and the second electrode and which contains fullerene C60 or fullerene C70 as a first organic semiconductor material and a second organic semiconductor material having an ionization potential of 0-5.0 eV.

Description

[Technical field]

[0001] The present disclosure relates to a photoelectric conversion element using, for example, an organic material, and an imaging element including the same. [Background technology]

[0002] For example, Patent Document 1 discloses an imaging element in which light receiving sections that detect light in different wavelength ranges are stacked. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-332551 A Summary of the Invention

[0004] Meanwhile, there is a demand for further improvement in the sensitivity of image pickup devices.

[0005] It is desirable to provide a photoelectric conversion element and an imaging element that can improve the sensitivity.

[0006] One embodiment of the present disclosure Light The electric conversion element includes a first electrode, a second electrode disposed opposite to the first electrode, and a fullerene C as a first organic semiconductor material provided between the first electrode and the second electrode. 60 or fullerene C 70 and as a second organic semiconductor material, any one of tetrathiafulvalene derivatives represented by formulas (1-2) to (1-9) described below, having an ionization potential of 0 to 5.0 eV. a fourth organic semiconductor material having hole transport properties; and a photoelectric conversion layer including The photoelectric conversion layer contains the second organic semiconductor material in a volume density range of 2% to 10% of the volume density of the first organic semiconductor material contained in the photoelectric conversion layer. .

[0007] One embodiment of the present disclosure Shooting The imaging element may include one or more of the above-described embodiments of the present disclosure for each of a plurality of pixels. Light It is equipped with an electric conversion element.

[0010] One embodiment of the present disclosure Light Electric conversion element and one embodiment Shooting In the imaging device, fullerene C, the first organic semiconductor material, was used. 60 or fullerene C 70 a second organic semiconductor material having an ionization potential of 0 to 5.0 eV; a fourth organic semiconductor material having hole transport properties; Using and the second organic semiconductor material is contained in the photoelectric conversion layer in an amount ranging from 2% to 10% of the volume density of the first organic semiconductor material contained in the photoelectric conversion layer. A photoelectric conversion layer is formed. .child This allows efficient charge separation of multiple excitons generated within the fullerene aggregate system. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view illustrating an example of a schematic configuration of a photoelectric conversion element according to a first embodiment of the present disclosure. [Diagram 2] 2 is a block diagram illustrating a configuration of an imaging element including the photoelectric conversion element shown in FIG. [Diagram 3] FIG. 1 is a diagram showing the energy spectrum of excited state fullerene C60. [Figure 4] FIG. 2 is a schematic diagram illustrating the relationship between fullerene C60 molecules and dopant molecules in an organic photoelectric conversion layer. [Diagram 5] 1 is a diagram showing the energy difference between the first nearest neighboring fullerene C60 and the second nearest neighboring fullerene C60 when a cation is doped into a fullerene C60 aggregation system. [Figure 6] FIG. 4 is a cross-sectional view illustrating an example of a schematic configuration of a photoelectric conversion element according to a second embodiment of the present disclosure. [Figure 7] FIG. 2 is a schematic diagram illustrating the relationship between fullerene C60 molecules and dopant molecules in an organic photoelectric conversion layer. [Figure 8] FIG. 1 is a diagram showing the energy difference between the first nearest neighboring fullerene C60 and the second nearest neighboring fullerene C60 when an electric dipole moment is doped into a fullerene C60 aggregate system. [Figure 9] 1 is a diagram showing the relationship between the energy difference between the first proximal fullerene C60 and the second proximal fullerene C60 and the magnitude of the electric dipole moment. [Figure 10]1 is a schematic cross-sectional view illustrating an example of a schematic configuration of a photoelectric conversion element according to a first modified example of the present disclosure. [Figure 11] 10 is a cross-sectional view illustrating another example of a schematic configuration of a photoelectric conversion element according to Modification 1 of the present disclosure. FIG. [Figure 12] 11 is a cross-sectional view illustrating an example of a schematic configuration of a photoelectric conversion element according to Modification 2 of the present disclosure. FIG. [Figure 13] 3 is a block diagram illustrating an example of the configuration of an electronic device having the imaging element illustrated in FIG. 2. [Figure 14] 1 is a diagram illustrating an example of a schematic configuration of an endoscopic surgery system. [Figure 15] 2 is a block diagram showing an example of a functional configuration of a camera head and a CCU. FIG. [Figure 16] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Figure 17] 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following aspect. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of each component shown in each drawing. The order of description is as follows. 1. First embodiment (example of photoelectric conversion element having an organic photoelectric conversion layer containing fullerene and an organic semiconductor material having an ionization potential of 5.0 eV or less) 1-1. Photoelectric conversion element configuration 1-2.Image sensor configuration 1-3. Actions and Effects 2. Second embodiment (an example of a photoelectric conversion element having an organic photoelectric conversion layer containing a fullerene 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 excited state) 2-1. Photoelectric conversion element configuration 2-2. Actions and Effects 3. Variations 3-1. Modification 1 (Example of adding a spectral adjustment layer) 3-2. Modification 2 (Example of stacking organic photoelectric conversion layers having different spectral characteristics) 4. Application Examples 5. Application Examples

[0013] <1. First embodiment> FIG. 1 illustrates an example of a cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10A) according to a first embodiment of the present disclosure. FIG. 2 illustrates an example of an overall configuration of an imaging element (imaging element 1) including the photoelectric conversion element 10A illustrated in FIG. 1. The photoelectric conversion element 10A constitutes one pixel (unit pixel P) in an imaging element 1 such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor used in electronic devices such as digital still cameras and video cameras. The photoelectric conversion element 10A according to the present embodiment has an organic photoelectric conversion section 20, and an organic photoelectric conversion layer 22 included in the organic photoelectric conversion section 20 is formed of fullerene (fullerene C 60 or fullerene C 70 ) and an organic semiconductor material with an ionization potential of 5.0 eV or less.

[0014] (1-1. Configuration of photoelectric conversion element) The photoelectric conversion element 10A has, for example, one organic photoelectric conversion unit 20. The organic photoelectric conversion unit 20 has an organic photoelectric conversion layer 22 formed using the above-mentioned organic semiconductor material as an organic material between a lower electrode 21 (first electrode) and an upper electrode 23 (second electrode) that are arranged opposite to each other. The organic photoelectric conversion unit 20 detects some or all of the wavelengths in the visible light region (for example, not less than 400 nm and not more than 760 nm).

[0015] In this embodiment, above (light incident side) the organic photoelectric conversion section 20, color filters 51 (color filters 51R, 51G, 51B) that selectively transmit red light (R), green light (G), and blue light (B) are provided for each unit pixel P (unit pixels Pr, Pg, Pb). As a result, in the unit pixel Pr in which the color filter 51R is provided, the organic photoelectric conversion section 20 detects the red light transmitted through the color filter 51R, and generates a signal charge corresponding to the red light (R). In the unit pixel Pg in which the color filter 51G is provided, the organic photoelectric conversion section 20 detects the green light transmitted through the color filter 51G, and generates a signal charge corresponding to the green light (G). In the unit pixel Pb in which the color filter 51B is provided, the organic photoelectric conversion section 20 detects the blue light transmitted through the color filter 51B, and generates a signal charge corresponding to the blue light (B).

[0016] The photoelectric conversion element 10A further includes, for example, one inorganic photoelectric conversion unit 32. The inorganic photoelectric conversion unit 32 is embedded and formed in the semiconductor substrate 30. The inorganic photoelectric conversion unit 32 detects light in a wavelength range different from that of the organic photoelectric conversion unit 20 and performs photoelectric conversion. That is, the organic photoelectric conversion unit 20 and the inorganic photoelectric conversion unit 32 detect light in different wavelength ranges and perform photoelectric conversion. Specifically, the organic photoelectric conversion unit 20 detects wavelengths in the visible light range, and the inorganic photoelectric conversion unit 32 detects wavelengths in the infrared light range (for example, 700 nm or more and 1500 nm or less).

[0017] The organic photoelectric conversion unit 20 and the inorganic photoelectric conversion unit 32 are stacked, for example, in the vertical direction. Specifically, the organic photoelectric conversion unit 20 is disposed, for example, on the light incident side S1 side, and is provided, for example, on the first surface 30A (rear surface) side of the semiconductor substrate 30.

[0018] As a result, among the light transmitted through each color filter 51R, 51G, 51B, light in the visible light region (R, G, B) is absorbed by the organic photoelectric conversion section 20, and other light, specifically, light in the infrared light region, is transmitted through the organic photoelectric conversion section 20. The light in the infrared light region (hereinafter simply referred to as infrared light (IR)) transmitted through the organic photoelectric conversion section 20 is detected by the inorganic photoelectric conversion section 32 of each unit pixel Pr, Pg, Pb, and a signal charge corresponding to the infrared light (IR) is generated in each unit pixel Pr, Pg, Pb. That is, the imaging element 1 including the photoelectric conversion element 10A is capable of simultaneously generating both a visible light image and an infrared light image.

[0019] In this embodiment, a case where electrons among pairs of electrons and holes (electron-hole pairs) generated by photoelectric conversion are read out as signal charges (when an n-type semiconductor region is used as a photoelectric conversion layer) will be described. In addition, in the figure, a "+ (plus)" attached to "n" indicates that the n-type impurity concentration is high.

[0020] On the second surface 30B (front surface) of the semiconductor substrate 30, for example, a charge retention portion 33, and although not shown, a pixel transistor and a multilayer wiring layer 40 are provided. In the multilayer wiring layer 40, for example, wiring layers 41, 42, and 43 are stacked in an insulating layer 44.

[0021] In the drawings, the back surface (first surface 30A) of the semiconductor substrate 30 is represented as a light incident side S1, and the front surface (second surface 30B) is represented as a wiring layer side S2.

[0022] As described above, the organic photoelectric conversion unit 20 has a configuration in which the lower electrode 21, the organic photoelectric conversion layer 22, and the upper electrode 23 are laminated in this order from the first surface 30A side of the semiconductor substrate 30. The lower electrode 21 is formed separately for each photoelectric conversion element 10A, for example. In FIG. 1, an example is shown in which the organic photoelectric conversion layer 22 and the upper electrode 23 are provided as a continuous layer common to each unit pixel Pr, Pg, Pb, but similar to the lower electrode 21, the organic photoelectric conversion layer 22 and the upper electrode 23 may be formed separately for each unit pixel Pr, Pg, Pb.

[0023] For example, an interlayer insulating layer 34 is provided between the first surface 30A of the semiconductor substrate 30 and the organic photoelectric conversion body 20. For example, a color filter 51 is provided above the upper electrode 23. Although not shown, for example, optical members such as a planarization layer and an on-chip lens are provided above the color filter 51.

[0024] Between the first surface 30A and the second surface 30B of the semiconductor substrate 30, a through electrode 35 is provided. The lower electrode 21 is electrically connected to the charge storage section 33 through the through electrode 35. That is, the through electrode 35 functions as a connector between the organic photoelectric conversion section 20 and the charge storage section 33, and also serves as a transmission path for the signal charge generated in the organic photoelectric conversion section 20. As a result, in the photoelectric conversion element 10A, the signal charge (here, electrons) generated in the organic photoelectric conversion section 20 on the first surface 30A side of the semiconductor substrate 30 can be transferred well to the second surface 30B side of the semiconductor substrate 30 through the through electrode 35, thereby improving the characteristics. For example, an insulating film 36 is provided around the through electrode 35, and is electrically insulated from the p-well 31.

[0025] In the organic photoelectric conversion section 20 of the present embodiment, light incident from the upper electrode 23 side is absorbed by the organic photoelectric conversion layer 22. The excitons generated by this move to the interface between the electron donor and electron acceptor constituting the organic photoelectric conversion layer 22, and are dissociated into excitons, that is, into electrons and holes. The charges (electrons and holes) generated here are transported to different electrodes by diffusion due to the difference in carrier concentration and an internal electric field due to the difference in work function between the anode (here, the upper electrode 23) and the cathode (here, the lower electrode 21), and are detected as a photocurrent. In addition, the transport direction of the electrons and holes can be controlled by applying a potential between the lower electrode 21 and the upper electrode 23.

[0026] The structure and materials of each part will be described below.

[0027] The organic photoelectric conversion section 20 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.

[0028] The lower electrode 21 attracts electrons as signal charges among the charges generated in the organic photoelectric conversion layer 22, and transfers the attracted signal charges to the charge holding section 33. The lower electrode 21 is made of a conductive film having optical transparency, and is made of, for example, ITO (indium tin oxide). However, in addition to ITO, the constituent material of the lower electrode 21 can also be tin oxide (SnO 2 Alternatively, a zinc oxide-based material obtained by adding a dopant to zinc oxide (ZnO) may be used. Examples of the zinc oxide-based material include aluminum zinc oxide (AZO) to which aluminum (Al) is added as a dopant, gallium zinc oxide (GZO) to which gallium (Ga) is added, and indium zinc oxide (IZO) to which indium (In) is added. Examples of the material for the lower electrode 21 include CuI, InSbO 4 , ZnMgO, CuInO 2 , MgIN 2 O 4 , CdO, ZnSnO 3 or TiO 2 Furthermore, spinel oxides and YbFe 2 O 4 An oxide having the structure may also be used.

[0029] The organic photoelectric conversion layer 22 converts light energy into electrical energy. The organic photoelectric conversion layer 22 is made of fullerene C represented by the following formula (4): 60 Or fullerene C represented by the following formula (5): 70 and an organic semiconductor material having an ionization potential of 5.0 eV or less. In addition, when there is no particular need to distinguish between them, fullerene C 60 and fullerene C 70 are collectively called fullerenes.

[0030] [ka]

[0031] Fullerenes absorb light in the blue region. Fullerenes have high cohesion. The five fullerenes C 60 The photoexcitation energy of the condensed system of was calculated using the time-dependent density functional theory (TDDFT), which is one of the first-principles calculation methods, taking into account thermal vibration, and the energy spectrum diagram shown in Figure 3 was obtained. The calculation conditions were the functional ωB97XD, the basis set 3-21G(d), and the number of excited states S1-S75 (up to the 75th singlet). 60 In the aggregated system of multiple fullerenes C 60 Multiple excitons are generated that are spread between molecules. Multiple excitons have a small binding energy. Therefore, multiple excitons are easier to separate charges than normal single excitons. In other words, multiple excitons are easier to photoelectrically convert than single excitons. By utilizing this, it is possible to improve the photoelectric conversion efficiency for light in the blue region.

[0032] From FIG. 3, it can be seen that the double exciton has an average energy 0.3 eV higher than the single exciton, and the triple exciton has an average energy 0.4 eV higher than the single exciton. In general, the energy difference (ΔE) at the p / n junction interface of a photoelectric conversion element is 0.3 eV to 0.4 eV. Considering that the energy difference (ΔE) at the p / n junction interface is 0.35 eV on average, it is presumed that the double exciton and the triple exciton can be efficiently charge-separated by creating an energy difference of ΔE≧0.05 eV in the organic photoelectric conversion layer 22 containing fullerene.

[0033] The organic semiconductor material having an ionization potential of 5.0 eV or less is intended to create an energy difference of ΔE≧0.05 eV in the organic photoelectric conversion layer 22. The organic semiconductor material having an ionization potential of 5.0 eV or less is likely to become a cation in the organic photoelectric conversion layer 22. For example, as shown in FIG. 60When an organic semiconductor material having an ionization potential of 5.0 eV or less is doped into a film made of the above material (hereinafter, the organic semiconductor material having an ionization potential of 5.0 eV or less is referred to as a dopant), the first nearest neighbor C 60 and the second closest C 60 5, for example, an energy difference (ΔE) of 0.18 eV occurs between the organic semiconductor material having an ionization potential of 5.0 eV or less. In other words, by doping with an organic semiconductor material having an ionization potential of 5.0 eV or less, a plurality of fullerenes C 60 This allows efficient charge separation of biexcitons and triple excitons spread between molecules.

[0034] The amount of the organic semiconductor material having an ionization potential of 5.0 eV or less added is preferably, for example, 2% to 10% of the volume density of the fullerene contained in the organic photoelectric conversion layer 22. If the doping concentration is too high, the generation of multiple excitons in the aggregation system of the fullerene is suppressed. Therefore, for example, fullerene C 60 When doping a film made of fullerene C with an organic semiconductor material having an ionization potential of 5.0 eV or less, 60 Molecular (1st nearest neighbor C 60 ), the number of doping atoms is about 10, so it is preferable to add an organic semiconductor material having an ionization potential of 5.0 eV or less at 10% or less. On the other hand, if the doping concentration is too low, there is a risk that sufficient photoelectric conversion efficiency cannot be obtained. For example, if it is less than 2%, it becomes difficult to control the doping concentration in the process, and stable characteristics cannot be obtained. For this reason, it is preferable to add an organic semiconductor material having an ionization potential of 5.0 eV or less at 2% or more.

[0035] An example of an organic semiconductor material having an ionization potential of 5.0 eV or less is a compound represented by the following general formula (1).

[0036] [ka] (X is any one of oxygen (O), sulfur (S) and selenium (Se). R1 ​​to R4 each independently represent a methyl group, a thiomethyl group, a hexamethylene group, an octamethylene group, an ethylenedithio group, a phenyl group, a biphenyl group, a terphenyl group, a naphthalene group, a phenylnaphthalene group, a biphenylnaphthalene group, a binathalene group, a thiophene group, a bithiophene group, a terthiophene group, a benzothiophene group, a phenylbenzothiophene group, a biphenylbenzothiophene group, a benzofuran group, a phenylbenzofuran group, a biphenylbenzothiophene group, an alkane group, a cycloalkane group, a fluorene group, a phenylfluorene group or a derivative thereof. R1 to R4 each independently represent an aromatic or non-aromatic hydrocarbon ring, a heterocyclic ring or a polycyclic fused ring between two adjacent substituents. Examples of the hydrocarbon ring, heterocyclic ring, and polycyclic condensed ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a triphenylene ring, a naphthacene ring, a biphenyl ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, 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 naphthyridine ring, a quinoxaline ring, a quinoxazoline ring, an isoquinoline ring, a carbazole ring, a phenanthridine ring, an acridine ring, a phenanthroline ring, a thianthrene ring, a chromene ring, a xanthene ring, a phenoxathiin ring, a phenothiazine ring, or a phenazine ring.

[0037] Specific examples of the compound represented by the above general formula (1) include tetrathiafulvalene and its derivatives represented by the following formulas (1-1) to (1-9). The tetrathiafulvalene and its derivatives represented by the formulas (1-1) to (1-9) correspond to specific examples of the "second organic semiconductor material" of the present disclosure.

[0038] [ka]

[0039] The organic photoelectric conversion layer 22 may further contain an organic material that converts light in a predetermined wavelength band in the visible light region (e.g., 400 nm or more and 760 nm or less) into electricity while transmitting light in other wavelength bands, that is, a so-called dye material. This dye material corresponds to a specific example of the "third organic semiconductor material" of the present disclosure.

[0040] Examples of the dye material include subphthalocyanine, dipyrromethene, merocyanine, squarylium, or derivatives thereof that absorb light in the wavelength band of 500 nm or more and 600 nm or less. Other examples of the dye material include naphthalene, anthracene, phenanthrene, tetracene, pyrene, perylene, and fluoranthene, or derivatives thereof. Alternatively, polymers such as phenylenevinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, and diacetylene, or derivatives thereof may be used. In addition, metal complex dyes, cyanine dyes, merocyanine dyes, phenylxanthene dyes, triphenylmethane dyes, rhodacyanine dyes, xanthene dyes, macrocyclic azaannulene dyes, azulene dyes, naphthoquinone, anthraquinone dyes, condensed polycyclic aromatics such as anthracene and pyrene, and chain compounds in which aromatic rings or heterocyclic compounds are condensed, or two nitrogen-containing heterocycles such as quinoline, benzothiazole, and benzoxazole having a squarylium group and a croconite methine group as a binding chain, or cyanine-like dyes bonded by a squarylium group and a croconite methine group, etc. can be preferably used. Note that, as the above-mentioned metal complex dyes, dithiol metal complex dyes, metal phthalocyanine dyes, metal porphyrin dyes, or ruthenium complex dyes are preferred, but are not limited thereto.

[0041] In this way, by forming the organic photoelectric conversion layer 22 using three types of organic semiconductor materials, namely, fullerene, an organic semiconductor material (dopant) with an ionization potential of 5.0 eV or less, and a dye material, it is possible to absorb a wide range of light in the visible light region.

[0042] The organic photoelectric conversion layer 22 may further contain an organic semiconductor material having a hole transporting property. This organic semiconductor material having a hole transporting property corresponds to a specific example of the "fourth organic semiconductor material" of 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, and tetracene or a derivative thereof.

[0043] When the organic photoelectric conversion layer 22 is formed using three types of organic semiconductor materials, namely, fullerene, an organic semiconductor material (dopant) having an ionization potential of 5.0 eV or less, and an organic semiconductor material having hole transport properties, the fullerene and the organic semiconductor material having hole transport properties form a bulk heterojunction structure as a p-type semiconductor and an n-type semiconductor within the organic photoelectric conversion layer 22. The bulk heterojunction structure is a p / n junction surface formed by mixing a p-type semiconductor and an n-type semiconductor, and excitons generated when light is absorbed are separated into electrons and holes at the p / n junction interface.

[0044] In addition, a p-type semiconductor functions relatively as an electron donor (donor), and an n-type semiconductor functions relatively as an electron acceptor (acceptor). The above organic semiconductor materials function as p-type or n-type semiconductors depending on the combination thereof.

[0045] The organic photoelectric conversion layer 22 may be formed using four types of organic semiconductor materials: fullerene, an organic semiconductor material (dopant) having an ionization potential of 5.0 eV or less, a dye material, and an organic semiconductor material having hole transport properties.

[0046] The organic photoelectric conversion layer 22 can be formed, for example, by mixing the various organic semiconductor materials described above and using a vacuum deposition method. Alternatively, for example, a spin coating technique or a printing technique may be used.

[0047] The upper electrode 23, like the lower electrode 21, is made of a conductive film having optical transparency.

[0048] Other layers may 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, a work function adjustment layer, and the like may be laminated in this order from the lower electrode 21 side. Furthermore, an undercoat layer and a hole transport layer may be provided between the lower electrode 21 and the organic photoelectric conversion layer 22, and a buffer layer and an electron transport layer may be provided between the organic photoelectric conversion layer 22 and the upper electrode 23.

[0049] The semiconductor substrate 30 is, for example, an n-type silicon (Si) substrate, and has a p-well 31 in a predetermined region.

[0050] The inorganic photoelectric conversion unit 32 is composed of, 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 unit 32 detects light (infrared light (IR)) in a part or all of the wavelength range of the infrared light region. In addition to the charge holding unit 33, pixel transistors including a transfer transistor, an amplification transistor, a reset transistor, etc. are provided on the second surface 30B of the semiconductor substrate 30.

[0051] The interlayer insulating layer 34 is, for example, silicon oxide (SiO x ), TEOS, silicon nitride (SiN x It is composed of a single layer film made of one of silicon oxynitride (SiON) and silicon oxide nitride (SiON), or a laminate film made of two or more of these.

[0052] The through electrode 35 can be formed using, for example, a doped silicon material such as PDAS (Phosphorus Doped Amorphous Silicon), as well as a metal material such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf), and tantalum (Ta).

[0053] The insulating film 36 is for electrically isolating the semiconductor substrate 30 from the through-electrodes 35, and is made of silicon oxide (SiO x ), TEOS, silicon nitride (SiN x ) and silicon oxynitride (SiON), or the like.

[0054] (1-2. Configuration of the image sensor) The imaging element 1 is, for example, a CMOS image sensor, which takes in incident light (image light) from a subject via an optical lens system (not shown), converts the amount of incident light imaged on an imaging surface into an electrical signal on a pixel-by-pixel basis, and outputs the electrical signal as a pixel signal. The imaging element 1 has a pixel section 100 as an imaging area on a semiconductor substrate 30, and has, 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 the peripheral region of the pixel section 100.

[0055] The pixel section 100 has a plurality of unit pixels P arranged two-dimensionally in a matrix, for example. In the unit pixels P, for example, a pixel drive line Lread (specifically, a row selection line and a reset control line) is wired for each pixel row, and a vertical signal line Lsig is wired for each pixel column. The pixel drive line Lread transmits a drive signal for reading out a signal from the 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.

[0056] The vertical drive circuit 111 is a pixel drive section that includes a shift register, an address decoder, and the like, and drives each unit pixel P of the pixel section 100, for example, row by row. Signals output from each unit pixel P of a pixel row selected and scanned by the vertical drive circuit 111 are supplied to a column signal processing circuit 112 through each vertical signal line Lsig. The column signal processing circuit 112 is configured with an amplifier, a horizontal selection switch, and the like provided for each vertical signal line Lsig.

[0057] The horizontal drive circuit 113 is composed of a shift register, an address decoder, etc., and sequentially drives while scanning each horizontal selection switch of the column signal processing circuit 112. By selective scanning by this horizontal drive circuit 113, signals of each pixel transmitted through each vertical signal line Lsig are output in sequence to a horizontal signal line 121, and transmitted to the outside of the semiconductor substrate 30 through the horizontal signal line 121.

[0058] The output circuit 114 processes and outputs signals sequentially supplied from each of the column signal processing circuits 112 via a horizontal signal line 121. The output circuit 114 may perform only buffering, or may perform black level adjustment, column variation correction, various digital signal processing, and the like.

[0059] A circuit portion consisting of 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 may be formed directly on the semiconductor substrate 30, or may be disposed in an external control IC. Moreover, these circuit portions may be formed on another substrate connected by a cable or the like.

[0060] The control circuit 115 receives a clock and data instructing an operation mode provided from outside the semiconductor substrate 30, and also outputs data such as internal information of the image sensor 1. The control circuit 115 further has a timing generator that generates various timing signals, and performs drive control 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.

[0061] The input / output terminal 16 is used to exchange signals with the outside.

[0062] (1-3. Actions and Effects) In the photoelectric conversion element 10A of the present embodiment and the imaging element 1 including the same, the organic photoelectric conversion layer 22 is made of fullerene C represented by formula (4). 60Or fullerene C represented by formula (5) 70 and an organic semiconductor material having an ionization potential of 5.0 eV or less, for example, represented by general formula (1). This makes it possible to efficiently separate charges from multiple excitons generated in a fullerene aggregation system formed in the organic photoelectric conversion layer 22. This will be described below.

[0063] Image sensors using organic photoelectric conversion films have been developed for CCD (Charge Coupled Device) image sensors and CMOS image sensors. For example, an image sensor using a multi-layered organic photoelectric conversion film 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. In this image sensor, sensitivity is improved by separately extracting B / G / R signals from one pixel. In addition, an image sensor has been proposed in which a layer of organic photoelectric conversion film is stacked above a semiconductor substrate on which a photodiode is formed as an inorganic photoelectric conversion section. In this image sensor, one color signal is extracted from the organic photoelectric conversion film, and two color signals are extracted from silicon (Si) bulk spectroscopy.

[0064] In recent years, there has been a demand for the development of image sensors capable of capturing images obtained from both visible light and infrared (IR) light. For example, when the above-mentioned organic imaging element is applied, a wider range of visible light can be absorbed, but there is a problem that it is difficult to manufacture it in a commercially viable size with current technology.

[0065] On the other hand, when a single-layer organic photoelectric conversion film is used as a visible light photoelectric conversion film, improving the sensitivity becomes an issue.

[0066] In contrast, in the present embodiment, fullerene C represented by formula (4) 60 Or fullerene C represented by formula (5) 70and an organic semiconductor material having an ionization potential of 5.0 eV or less, for example, represented by general formula (1), are used to form the organic photoelectric conversion layer 22. This makes it possible to efficiently separate charges from multiple excitons generated in a fullerene aggregation system formed in the organic photoelectric conversion layer 22. In other words, it becomes possible to use fullerene as a light absorbing material in the blue region.

[0067] As a result, in the photoelectric conversion element 10A of the present embodiment, it is possible to improve the photoelectric conversion efficiency of blue light in the organic photoelectric conversion layer 22. As a result, by forming the organic photoelectric conversion layer 22 together with an organic semiconductor material, which is a so-called dye material, such as subphthalocyanine, it is possible to perform photoelectric conversion in a wider range of the visible light region. In other words, it is possible to provide an imaging element with high sensitivity.

[0068] In addition, in the present embodiment, the composition of fullerene can be increased compared to the organic photoelectric conversion layer of a general organic photoelectric conversion element, so that the electronic conductivity can be improved. This allows the signal charge generated in the organic photoelectric conversion layer 22 to be quickly transferred to the lower electrode 21. This makes it possible to improve the image quality of the captured image.

[0069] Next, a second embodiment of the present disclosure and modifications 1 and 2 will be described. In the following, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0070] <2. Second embodiment> FIG. 6 shows an example of a cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10B) according to the second embodiment of the present disclosure. Like the photoelectric conversion element 10A in the first embodiment, the photoelectric conversion element 10B constitutes one pixel (unit pixel P) in an imaging element 1 such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. In the photoelectric conversion element 10B of this embodiment, the organic photoelectric conversion layer 62 is made of fullerene (fullerene C 60 or fullerene C70 ) 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 excited state.

[0071] (2-1. Configuration of photoelectric conversion element) The photoelectric conversion element 10B has, for example, a configuration in which one organic photoelectric conversion unit 60 and one inorganic photoelectric conversion unit 32 are stacked in the vertical direction. The organic photoelectric conversion unit 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 to generate electron-hole pairs, and has an organic photoelectric conversion layer 62 formed using the above-mentioned organic semiconductor material as an organic material between a lower electrode 21 and an upper electrode 23 arranged opposite to each other.

[0072] An 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 is intended to create an energy difference of ΔE≧0.05 eV within the organic photoelectric conversion layer 22, similar to the organic semiconductor material having an ionization potential of 5.0 eV or less in the first embodiment described above.

[0073] For example, as shown in Figure 7, fullerene C 60 When an organic semiconductor material having an electric dipole moment of 10 Debye or more in the ground state or excited state is doped into a film made of the above (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), the first nearest neighbor C 60 and the second closest C 60 8 and 9, for example, an energy difference (ΔE) of 0.05 eV or more occurs between the fullerenes C 60 This allows efficient charge separation of biexcitons and triple excitons spread between molecules.

[0074] In addition, in organic semiconductor materials in which the electric dipole moment in the ground state or excited state is larger than 30 Debye, there is a risk that the mobility will decrease due to carrier scattering.60 The electric dipole moment in the ground state or excited state of the organic semiconductor material doped into the film made of the above is preferably 30 Debye or less.

[0075] The 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 excited state added is preferably, for example, 2% or more and 10% or less of the volume density of the fullerene contained in the organic photoelectric conversion layer 22, as in the first embodiment. If the doping concentration is too high, the generation of multiple excitons in the aggregation system of the fullerene is suppressed. Therefore, for example, fullerene C 60 When a film made of is doped with an organic semiconductor material having an electric dipole moment of 10 Debye or more and 30 Debye or less in the ground or excited state, the fullerene C closest to the dopant 60 Molecular (1st nearest neighbor C 60 ) is about 10, so 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 added is preferably 10% or less. On the other hand, if the doping concentration is too low, there is a risk that sufficient photoelectric conversion efficiency will not be obtained. For example, if it is less than 2%, it becomes difficult to control the doping concentration in the process, and stable characteristics cannot be obtained. For this reason, it is preferable that 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 added is 2% or more.

[0076] Examples of organic semiconductor materials having an electric dipole moment of 10 Debye or more and 30 Debye or less in the ground state or excited state include cyanine compounds having a parent skeleton represented by the following general formula (2), in which A has any one of the following substituents (A-1) to (A-6) and B has any one of the following substituents (B-1) to (B-6).

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] Other examples of organic semiconductor materials having an electric dipole moment in the ground state or excited state of 10 Debye or more and 30 Debye or less include compounds represented by the following general formula (3).

[0081] [ka] (R5 to R7 each 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 aryloxycarbonyloxy group, an amino group, an ammonio group, an acylamino group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfamoylamino group, an alkyl ... Sulfonylamino group, arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkylsulfinyl group, arylsulfinyl group, alkylsulfol group, arylsulfol group, acyl group, aryloxycarbonyl group, alkoxycarbol group, carbamoyl group, arylcyclic azo group, heterocyclic azo group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, phosphono group, silyl group, hydrazino group, ureido group, boronic acid group (-B(OH) 2 ), sulfato group (-OSO 3 H) or a derivative thereof.

[0082] Examples of the alkyl group include a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group. Examples of the alkenyl group include a cycloalkenyl group and a bicycloalkenyl group. Examples of the amino group include an alkylamino group, an arylamino group, and a heterocyclic amino group.

[0083] Specific examples of the compound represented by the above general formula (3) include coumarin derivatives represented by the following formulae (3-1) to (3-5).

[0084] [ka]

[0085] The cyanine compound represented by general formula (2) having any one of the above formulas (A-1) to (A-6) and any one of the formulas (B-1) to (B-6) and the coumarin derivative represented by the above formulas (3-1) to (3-5) correspond to a specific example of the "second organic semiconductor material" of the present disclosure.

[0086] The organic photoelectric conversion layer 62 may further contain an organic material that converts light in a predetermined wavelength band in the visible light range into electricity while transmitting light in other wavelength bands, that is, a so-called dye material, in the same manner as the organic photoelectric conversion layer 22 in the first embodiment. Also, the organic photoelectric conversion layer 62 may further contain an organic semiconductor material having a hole transport property, in the same manner as the organic photoelectric conversion layer 22 in the first embodiment.

[0087] The organic photoelectric conversion layer 62 can be formed by, for example, mixing the various organic semiconductor materials described above and using a vacuum deposition method. Alternatively, for example, a spin coating technique or a printing technique may be used.

[0088] (2-2. Actions and Effects) In the photoelectric conversion element 10B of the present embodiment and the imaging element 1 including the same, the organic photoelectric conversion layer 62 is made of fullerene C represented by formula (4). 60 Or fullerene C represented by formula (5)70 and a cyanine compound represented by general formula (2) having, for example, any one of formulas (A-1) to (A-6) and any one of formulas (B-1) to (B-6), or a coumarin derivative represented by the above formulas (3-1) to (3-5), whose electric dipole moment in the ground state or excited state is 10 Debye or more and 30 Debye or less. This makes it possible to efficiently charge separate multiple excitons generated in a fullerene aggregation system formed in the organic photoelectric conversion layer 62, and makes it possible to use fullerene as a light absorbing material in the blue region.

[0089] As a result, in the photoelectric conversion element 10B of the present embodiment, it is possible to improve the photoelectric conversion efficiency of blue light in the organic photoelectric conversion layer 62. As a result, by forming the organic photoelectric conversion layer 62 together with an organic semiconductor material, which is a so-called dye material, such as subphthalocyanine, it is possible to perform photoelectric conversion in a wider range of the visible light region. In other words, it is possible to provide an imaging element with high sensitivity.

[0090] In addition, in the present embodiment, the composition of fullerene can be increased compared to the organic photoelectric conversion layer of a general organic photoelectric conversion element, so that the electronic conductivity can be improved. This allows the signal charge generated in the organic photoelectric conversion layer 62 to be quickly transferred to the lower electrode 21. This makes it possible to improve the image quality.

[0091] <3. Modifications> (3-1. Variation 1) 10 illustrates an example of a cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10C) according to Modification 1 of the present disclosure. The photoelectric conversion element 10A described in the first embodiment may further include, for example, a dual bandpass filter 71 as a spectral adjustment layer.

[0092] The dual bandpass filter 71 has a transmission band in each of the visible light region and the infrared light region, and is provided above the color filter 51, for example.

[0093] However, as in the first embodiment, when the color filters 51R, 51G, and 51B and the organic photoelectric conversion unit 20 are arranged above the first surface 30A, which is the light incident surface of the semiconductor substrate 30, the infrared light absorbed by the inorganic photoelectric conversion unit 32 of each unit pixel Pr, Pg, and Pb is light that has passed through each color filter 51R, 51G, and 51B and the organic photoelectric conversion unit 20. That is, the spectrum of the infrared light absorbed by the inorganic photoelectric conversion unit 32 of each unit pixel Pr, Pg, and Pb is different from each other. Therefore, since the sensitivity differs for each unit pixel Pr, Pg, and Pb, there is a problem that each unit pixel Pr, Pg, and Pb cannot be used as an IR pixel for generating the same infrared light image.

[0094] In contrast, in this modification, by providing a dual bandpass filter 71, the infrared light detected by the inorganic photoelectric conversion unit 32 becomes light within the wavelength region of the transmission band on the infrared light region side of the dual bandpass filter 71, and it is possible to align the spectrum of the infrared light detected in each unit pixel Pr, Pg, Pb. As a result, in the photoelectric conversion element 10C, it becomes possible to obtain an IR image using IR signals obtained from all unit pixels Pr, Pg, Pb arranged in a two-dimensional manner. Therefore, in addition to the effect of the first embodiment, it is possible to provide an imaging element 1 capable of obtaining a high-resolution IR image.

[0095] As the spectral adjustment layer, in addition to the dual bandpass filter 71, for example, a multilayer filter 81 can be used as in the photoelectric conversion element 10D shown in FIG. 11. The multilayer filter 81 is formed by periodically and alternately laminating, for example, a film made of an inorganic material with a high refractive index and a film made of an inorganic material with a low refractive index. An example of the inorganic material with a high refractive index is silicon nitride (Si 3 N 4 ) and titanium dioxide (TiO2 ) and the like. Examples of inorganic materials with a low refractive index include silicon oxide (SiO 2 The multilayer filter 81 can be provided, for example, between the organic photoelectric conversion section 20 and the interlayer insulating layer .

[0096] In addition, for example, a plasmon filter may be provided between the organic photoelectric conversion section 20 and the semiconductor substrate 30 to obtain the same effect.

[0097] (3-2. Variation 2) 12 shows a cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10E) according to Modification 2 of the present disclosure. The photoelectric conversion element 10E constitutes one unit pixel P in an imaging element (imaging element 1) such as a CMOS image sensor capable of capturing an image obtained from visible light. The photoelectric conversion element 10E of this modification has a configuration in which a red photoelectric conversion unit 90R, a green photoelectric conversion unit 90G, and a blue photoelectric conversion unit 90B are stacked in this order on a semiconductor substrate 30 via an insulating layer 96.

[0098] The red photoelectric conversion unit 90R, the green photoelectric conversion unit 90G and the blue photoelectric conversion unit 90B each have an organic photoelectric conversion layer 92R, 92G, 92B between a pair of electrodes, specifically, between the first electrode 91R and the second electrode 93R, between the first electrode 91G and the second electrode 93G, and between the first electrode 91B and the second electrode 93B, respectively.

[0099] An on-chip lens 98L is provided on the blue photoelectric conversion unit 90B via a protective layer 97 and an on-chip lens layer 98. A red storage layer 310R, a green storage layer 310G, and a blue storage layer 310B are provided in the semiconductor substrate 30. Light incident on the on-chip lens 98L is photoelectrically converted by the red photoelectric conversion unit 90R, the green photoelectric conversion unit 90G, and the blue photoelectric conversion unit 90B, and signal charges are sent from the red photoelectric conversion unit 90R to the red storage layer 310R, from the green photoelectric conversion unit 90G to the green storage layer 310G, and from the blue photoelectric conversion unit 90B to the blue storage layer 310B, respectively. The signal charges may be either electrons or holes generated by photoelectric conversion, but the following description will be given of an example in which electrons are read out as signal charges.

[0100] The semiconductor substrate 30 is made of, for example, a p-type silicon substrate. The red storage layer 310R, the green storage layer 310G, and the blue storage layer 310B provided on the semiconductor substrate 30 each include an n-type semiconductor region, and the signal charge (electrons) supplied from the red photoelectric conversion unit 90R, the green photoelectric conversion unit 90G, and the blue photoelectric conversion unit 90B is stored in the n-type semiconductor region. The n-type semiconductor regions of the red storage layer 310R, the green storage layer 310G, and the blue storage layer 310B are formed by doping the semiconductor substrate 30 with an n-type impurity such as phosphorus (P) or arsenic (As). The semiconductor substrate 30 may be provided on a support substrate (not shown) made of glass or the like.

[0101] The semiconductor substrate 30 is provided with pixel transistors for reading out electrons from the red storage layer 310R, the green storage layer 310G, and the blue storage layer 310B, and transferring them to, for example, a vertical signal line (vertical signal line Lsig in FIG. 2). The floating diffusions of the pixel transistors are provided in the semiconductor substrate 30, and are connected to the red storage layer 310R, the green storage layer 310G, and the blue storage layer 310B. The floating diffusions are formed of n-type semiconductor regions.

[0102] The insulating layer 96 is, for example, silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiON) and hafnium oxide (HfO x ) or the like. A plurality of types of insulating films may be laminated to form the insulating layer 96. The insulating layer 96 may be formed of an organic insulating material. The insulating layer 96 is provided with plugs and electrodes for respectively connecting the red storage layer 310R and the red photoelectric conversion unit 90R, the green storage layer 310G and the green photoelectric conversion unit 90G, and the blue storage layer 310B and the blue photoelectric conversion unit 90B.

[0103] The red photoelectric conversion unit 90R has a first electrode 91R, an organic photoelectric conversion layer 92R, and a second electrode 93R in this order from the position closest to the semiconductor substrate 30. The green photoelectric conversion unit 90G has a first electrode 91G, an organic photoelectric conversion layer 92G, and a second electrode 93G in this order from the position closest to the red photoelectric conversion unit 90R. The blue photoelectric conversion unit 90B has a first electrode 91B, an organic photoelectric conversion layer 92B, and a second electrode 93B in this order from the position closest to the green photoelectric conversion unit 90G. An insulating layer 44 is provided between the red photoelectric conversion unit 90R and the green photoelectric conversion unit 90G, and an insulating layer 95 is provided between the green photoelectric conversion unit 90G and the blue photoelectric conversion unit 90B. The red photoelectric conversion section 90R selectively absorbs red light (e.g., wavelength of 600 nm or more and less than 700 nm), the green photoelectric conversion section 90G selectively absorbs green light (e.g., wavelength of 480 nm or more and less than 600 nm), and the blue photoelectric conversion section 90B selectively absorbs blue light (e.g., wavelength of 400 nm or more and less than 480 nm), generating electron-hole pairs.

[0104] The first electrode 91R extracts the signal charge generated in the organic photoelectric conversion layer 92R, the first electrode 91G extracts the signal charge generated in the organic photoelectric conversion layer 92G, and the first electrode 91B extracts the signal charge generated in the organic photoelectric conversion layer 92B. The first electrodes 91R, 91G, and 91B are provided, for example, for each pixel. The first electrodes 91R, 91G, and 91B are made of, for example, a light-transmitting conductive material, specifically, ITO. The first electrodes 91R, 91G, and 91B may be made of, for example, a tin oxide-based material or a zinc oxide-based material. The tin oxide-based material is tin oxide to which a dopant has been added, and the zinc oxide-based material is, for example, 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. In addition to these, IGZO, CuI, InSbO 4 ,ZnMgO,CuInO 2 ,MgIn 2 O 4 , CdO and ZnSnO 3 It is also possible to use the following:

[0105] For example, an electron transport layer may be provided 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. The electron transport layer is for facilitating the supply of electrons generated in the organic photoelectric conversion layers 92R, 92G, and 92B to the first electrodes 91R, 91G, and 91B, and is made of, for example, titanium oxide or zinc oxide. The electron transport layer may be formed by laminating titanium oxide and zinc oxide.

[0106] The organic photoelectric conversion layers 92R, 92G, and 92B each absorb light in a selective wavelength range and 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 less than 700 nm in the organic photoelectric conversion layer 92R, light in a wavelength range of 480 nm or more and less than 600 nm in the organic photoelectric conversion layer 92G, and light in a wavelength range of 400 nm or more and less than 480 nm in the organic photoelectric conversion layer 92B.

[0107] The organic photoelectric conversion layers 92R, 92G, and 92B have the same configuration as the organic photoelectric conversion layer 12 in the above embodiment. For example, the organic photoelectric conversion layers 92R, 92G, and 92B are preferably configured to include two or more kinds of organic semiconductor materials, for example, either one or both of a p-type semiconductor and an n-type semiconductor. For example, when the organic photoelectric conversion layers 92R, 92G, and 92B are respectively configured with two kinds of organic semiconductor materials, a p-type semiconductor and an n-type semiconductor, it is preferable that one of the p-type semiconductor and the n-type semiconductor is a material that is transparent to visible light, and the other is a material that photoelectrically converts light in a selective wavelength range. Alternatively, it is preferable that the organic photoelectric conversion layers 92R, 92G, and 92B are respectively configured with three kinds of organic semiconductor materials, a material (dye material) that photoelectrically converts light in a selective wavelength range, and an n-type semiconductor and a p-type semiconductor that are transparent to visible light.

[0108] For example, the organic photoelectric conversion layer 92R preferably uses a material (dye material) capable of photoelectrically converting light in a wavelength range of 600 nm or more and less than 700 nm. Examples of such materials include subnaphthalocyanine or its derivatives, and phthalocyanine or its derivatives. For example, the organic photoelectric conversion layer 92G preferably uses a material (dye material) capable of photoelectrically converting light in a wavelength range of 480 nm or more and less than 600 nm. Examples of such materials include subphthalocyanine or its derivatives. For example, the organic photoelectric conversion layer 92B preferably uses a material (dye material) capable of photoelectrically converting light in a wavelength range of 400 nm or more and less than 480 nm. As described above, examples of such materials include fullerene (fullerene C 60 or fullerene C 70 ) and an organic semiconductor material having an ionization potential of 5.0 eV or less, or an organic semiconductor material having an electric dipole moment of 10 Debye to 30 Debye in the ground state or excited state. In addition to the above materials, the organic photoelectric conversion layer 92B may be formed by mixing, for example, coumarin or a derivative thereof and porphyrin or a derivative thereof.

[0109] 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, for example, a hole transport layer may be provided. The hole transport layer is for accelerating the supply of holes generated in the organic photoelectric conversion layers 92R, 92G, and 92B to the second electrodes 93R, 93G, and 93B, and is made of, for example, molybdenum oxide, nickel oxide, or vanadium oxide. The hole transport layer may be made of an organic material such as PEDOT (Poly(3,4-ethylenedioxythiophene)) and TPD (N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine).

[0110] The second electrode 93R is for extracting holes generated in the organic photoelectric conversion layer 92R, the second electrode 93G is for extracting holes generated in the organic photoelectric conversion layer 92G, and the second electrode 93B is for extracting holes generated in the organic photoelectric conversion layer 92G. The holes extracted from the second electrodes 93R, 93G, and 93B are discharged to, for example, a p-type semiconductor region (not shown) in the semiconductor substrate 30 via each transmission path (not shown). The second electrodes 93R, 93G, and 93B are made of a conductive material such as gold, silver, copper, and aluminum. As with the first electrodes 91R, 91G, and 91B, the second electrodes 93R, 93G, and 93B may be made of a transparent conductive material. In the photoelectric conversion element 10E, the holes extracted from the second electrodes 93R, 93G, and 93B are discharged. Therefore, for example, when multiple photoelectric conversion elements 10E are arranged in the imaging element 1 described later, the second electrodes 93R, 93G, and 93B may be provided in common to each photoelectric conversion element 10E (unit pixel P).

[0111] The insulating layer 94 is for insulating the second electrode 93R from the first electrode 91G, and the insulating layer 95 is for insulating the second electrode 93G from the first electrode 91B. The insulating layers 94 and 95 are made of, for example, a metal oxide, a metal sulfide, or an organic material. Examples of metal oxides include silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, zinc oxide, tungsten oxide, magnesium oxide, niobium oxide, tin oxide, and gallium oxide. Examples of metal sulfides include zinc sulfide and magnesium sulfide. The band gap of the material constituting the insulating layers 94 and 95 is preferably 3.0 eV or more.

[0112] As described above, the present technology can also be applied to a photoelectric conversion element (photoelectric conversion element 10E) in which a red photoelectric conversion unit 90R, a green photoelectric conversion unit 90G, and a blue photoelectric conversion unit 90B, each of which has a photoelectric conversion layer (organic photoelectric conversion layers 92R, 92G, 92B) made using an organic semiconductor material, are stacked in this order.

[0113] <4. Application Examples> The imaging element 1 can be applied to any type of electronic device having an imaging function, such as a camera system such as a digital still camera or a video camera, or a mobile phone having an imaging function. Fig. 13 shows a schematic configuration of an electronic device 1000.

[0114] The electronic device 1000 has an image sensor 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, which are interconnected via a bus line 1007.

[0115] The DSP circuit 1001 is a signal processing circuit that processes a signal supplied from the image sensor 1. The DSP circuit 1001 outputs image data obtained by processing the signal from the image sensor 1. The frame memory 1002 temporarily holds the image data processed by the DSP circuit 1001 for a frame.

[0116] The display unit 1003 is, 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 moving or still images captured by the imaging element 1 in a recording medium such as a semiconductor memory or a hard disk.

[0117] The operation unit 1005 outputs operation signals for various functions of the electronic device 1000 in accordance with operations by a user. The power supply unit 1006 appropriately supplies various types of power to the DSP circuit 1001, the frame memory 1002, the display unit 1003, the recording unit 1004, and the operation unit 1005 as operating power sources to these power sources.

[0118] <5. Application Examples> <Application example to endoscopic surgery system> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0119] FIG. 14 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0120] 14 shows a state in which an operator (doctor) 11131 is performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0121] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the illustrated example, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may be configured as a so-called flexible scope having a flexible lens barrel.

[0122] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an observation target in the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0123] An optical system and an image sensor are provided inside the camera head 11102, and reflected light (observation light) from an observation target is collected on the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to an observation image. The image signal is transmitted to a camera control unit (CCU) 11201 as RAW data.

[0124] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and performs overall control of the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102, and performs various types of image processing on the image signal, such as development processing (demosaic processing), for displaying an image based on the image signal.

[0125] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0126] The light source device 11203 is composed of a light source such as an LED (light emitting diode), and supplies the endoscope 11100 with irradiation light when photographing an operation site or the like.

[0127] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiated light, magnification, focal length, etc.) of the endoscope 11100.

[0128] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 sends gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing the field of view of the endoscope 11100 and securing the working space of the surgeon. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, image, or graph.

[0129] The light source device 11203 that supplies irradiation light to the endoscope 11100 when photographing the surgical site can be composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. When the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so that the white balance of the captured image can be adjusted in the light source device 11203. In this case, it is also possible to capture images corresponding to each of the RGB colors in a time-division manner by irradiating the observation object with laser light from each of the RGB laser light sources in a time-division manner and controlling the driving of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0130] The light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. The driving of the image sensor of the camera head 11102 may be controlled in synchronization with the timing of the change in the light intensity to obtain images in a time-division manner, and the images may be synthesized to generate an image with a high dynamic range that is free of so-called blackout and whiteout.

[0131] The light source device 11203 may be configured to supply light of a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, by utilizing the wavelength dependency of light absorption in body tissue, a narrow band light is irradiated compared to the irradiated light (i.e., white light) during normal observation, and a predetermined tissue such as blood vessels on the mucous membrane surface is photographed with high contrast, so-called narrow band imaging is performed. Alternatively, in the special light observation, a fluorescent observation may be performed in which an image is obtained by fluorescence generated by irradiating an excitation light. In the fluorescent observation, it is possible to irradiate an excitation light to a body tissue and observe the fluorescence from the body tissue (autofluorescence observation), or to locally inject a reagent such as indocyanine green (ICG) into the body tissue and irradiate the body tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0132] FIG. 15 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0133] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other by a transmission cable 11400 so as to be able to communicate with each other.

[0134] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is configured by combining a plurality of lenses including a zoom lens and a focus lens.

[0135] The imaging unit 11402 may include one imaging element (so-called single-plate type) or multiple imaging elements (so-called multiple-plate type). When the imaging unit 11402 is configured as a multiple-plate type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining the image signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to a 3D (dimensional) display. By performing a 3D display, the surgeon 11131 can more accurately grasp the depth of the biological tissue in the surgical site. Note that when the imaging unit 11402 is configured as a multiple-plate type, the lens unit 11401 may also be provided in multiple systems corresponding to each imaging element.

[0136] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately behind the objective lens.

[0137] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be appropriately adjusted.

[0138] The communication unit 11404 is configured by 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 via the transmission cable 11400 as RAW data.

[0139] Furthermore, 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. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of capturing the image, and / or information specifying the magnification and focus of the captured image.

[0140] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by a user, or may be automatically set by the control unit 11413 of the CCU 11201 based on an acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0141] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404.

[0142] The communication unit 11411 is configured with a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0143] Furthermore, the communication unit 11411 transmits, to the camera head 11102, a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0144] The image processing unit 11412 performs various types of image processing on the image signal, which is RAW data sent from the camera head 11102 .

[0145] The control unit 11413 performs various controls related to imaging of the surgical site etc. by the endoscope 11100 and display of the captured image obtained by imaging the surgical site etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0146] Further, the control unit 11413 causes the display device 11202 to display the captured image showing the surgical site, etc., based on the image signal that has been image-processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition techniques. For example, the control unit 11413 can recognize surgical tools such as forceps, specific living body parts, bleeding, mist when the energy treatment tool 11112 is used, etc., by detecting the shape and color of the edge of an object included in the captured image. When the control unit 11413 causes the display device 11202 to display the captured image, it may use the recognition result to superimpose various types of surgery support information on the image of the surgical site. By superimposing and presenting the surgery support information to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0147] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0148] Here, in the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0149] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 11402 among the configurations described above. By applying the technology according to the present disclosure to the imaging unit 11402, detection accuracy is improved.

[0150] Although an endoscopic surgery system has been described here as an example, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0151] <Applications to moving objects> The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, a construction machine, an agricultural machine (tractor), etc.

[0152] FIG. 16 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving object control system to which the technology according to the present disclosure can be applied.

[0153] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 16, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also, as functional configurations of the integrated control unit 12050, a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053 are illustrated.

[0154] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0155] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to 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 head lamps, back lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals of various switches transmitted from a portable device that replaces a key may be input to the body system control unit 12020. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, and the like of the vehicle.

[0156] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture an image outside the vehicle and receives the captured image. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for a person, a car, an obstacle, a sign, or characters on a road surface, based on the received image.

[0157] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0158] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing.

[0159] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the outside-of-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0160] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on the driver's operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0161] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside-vehicle information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.

[0162] The audio / video output unit 12052 transmits at least one output signal of audio and video to an output device capable of visually or audibly notifying information to passengers in the vehicle or the outside of the vehicle. In the example of Fig. 16, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as the output device. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

[0163] FIG. 17 is a diagram showing an example of the installation position of the imaging unit 12031.

[0164] In FIG. 17, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0165] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided at the upper part of the windshield inside the vehicle cabin is mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

[0166] 17 shows an example of the imaging ranges of the imaging units 12101 to 12104. An imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and an imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing the image data captured by the imaging units 12101 to 12104.

[0167] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of a plurality of imaging elements, or may be an imaging element having pixels for detecting a phase difference.

[0168] For example, the microcomputer 12051 can extract, as a preceding vehicle, a three-dimensional object that is the closest three-dimensional object on the travel path of the vehicle 12100 and travels at a predetermined speed (for example, 0 km / h or more) in approximately the same direction as the vehicle 12100, by calculating the distance to each three-dimensional object in the imaging ranges 12111 to 12114 and the change over time of this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. Furthermore, the microcomputer 12051 can set a vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of automatic driving that travels autonomously without relying on the driver's operation.

[0169] For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0170] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured images of the imaging units 12101 to 12104. The recognition of such a pedestrian is performed, for example, by a procedure of extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras, and a procedure of performing pattern matching processing on a series of feature points that indicate the contour of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

[0171] Although the first and second embodiments, the first and second modifications, and the application examples have been described above, the present disclosure is not limited to the above-mentioned embodiments, etc., and various modifications are possible. For example, the components, arrangements, numbers, etc. of the photoelectric conversion element 10A, etc., exemplified in the above-mentioned embodiments, etc., are merely examples, and it is not necessary to include all the components, and other components may be further included.

[0172] In the above-described embodiments, an example has been shown in which an organic photoelectric conversion unit 20 that detects the visible light region and an inorganic photoelectric conversion unit 32 that detects light in the infrared light region are stacked, but the organic photoelectric conversion unit 20 can also be used alone.

[0173] In addition, in the above-mentioned embodiment, the lower electrode 21 is formed of one electrode, but two or more electrodes, i.e., three or more electrodes, may be used. Furthermore, in the above-mentioned embodiment, the present technology has been described using a so-called back-illuminated image sensor as an example, 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 can also be applied to a front-illuminated image sensor.

[0174] In the above modified example, three organic photoelectric conversion units (red photoelectric conversion unit 90R, green photoelectric conversion unit 90G, blue photoelectric conversion unit 90B) that detect red light (R), green light (G), and blue light (B), respectively, are stacked, but the present invention is not limited thereto. For example, two organic photoelectric conversion units, an organic photoelectric conversion unit that detects blue light (B) and an organic photoelectric conversion unit that detects red light (R) and green light (G), may be stacked. For example, in the semiconductor substrate 30, an organic photoelectric conversion unit that detects red light (R) and green light (G) may be provided above the semiconductor substrate 30 to detect blue light (B). For example, in the semiconductor substrate 30, two organic photoelectric conversion units that detect red light (R) and green light (G) may be provided above the semiconductor substrate 30 to detect green light (G) and blue light (B), respectively. The techniques described in the first and second embodiments above may be applied to the organic photoelectric conversion unit that detects blue light (B).

[0175] It should be noted that the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained.

[0176] In addition, the present disclosure may have the following configuration. According to the present technology having the following configuration, the photoelectric conversion layer is The first organic semiconductor material Fullerene C 60 or fullerene C 70 and ionization potential is 0 to 5.0 eV. Second Organic Semiconductor Materials and a fourth organic semiconductor material having hole transport properties. Using At the same time, the second organic semiconductor material is contained in the photoelectric conversion layer in an amount ranging from 2% to 10% of the volume density of the first organic semiconductor material contained in the photoelectric conversion layer. Since the fullerene aggregate is formed in the fullerene layer, it is possible to efficiently separate the charges of the multiple excitons generated in the fullerene aggregate, and therefore it is possible to improve the sensitivity to blue light in particular. [1] A first electrode; a second electrode disposed opposite the first electrode; A first organic semiconductor material is provided between the first electrode and the second electrode, and fullerene C 60 or fullerene C 70and a second organic semiconductor material, which is a tetrathiafulvalene derivative having an ionization potential of 0 to 5.0 eV and represented by the following formulas (1-2) to (1-9). a fourth organic semiconductor material having hole transport properties; and a photoelectric conversion layer including 、 The photoelectric conversion layer contains the second organic semiconductor material in a volume density range of 2% to 10% of the volume density of the first organic semiconductor material contained in the photoelectric conversion layer. Photoelectric conversion element. [ka] [2 ] before The photoelectric conversion layer further includes a third organic semiconductor material. [1] The photoelectric conversion element according to claim 1. [3] The third organic semiconductor material has absorption in the wavelength range of 400 nm or more and 760 nm or less. [2] The photoelectric conversion element according to claim 1. [4] A plurality of pixels each having one or a plurality of photoelectric conversion elements, The photoelectric conversion element is A first electrode; a second electrode disposed opposite the first electrode; A first organic semiconductor material is provided between the first electrode and the second electrode, and fullerene C 60 or fullerene C 70 and a second organic semiconductor material, which is a tetrathiafulvalene derivative having an ionization potential of 0 to 5.0 eV and represented by the following formulas (1-2) to (1-9). a fourth organic semiconductor material having hole transport properties; A photoelectric conversion layer including death, The photoelectric conversion layer contains the second organic semiconductor material in a volume density range of 2% to 10% of the volume density of the first organic semiconductor material contained in the photoelectric conversion layer. Image sensor. [ka]

[0177] This application claims priority based on Japanese Patent Application No. 2019-198481, filed on October 31, 2019 in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0178] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur to those skilled in the art depending on design requirements and other factors, and that such modifications are within the scope of the appended claims and their equivalents.

Claims

1. A first electrode; a second electrode disposed opposite the first electrode; A first organic semiconductor material is provided between the first electrode and the second electrode, and fullerene C ６０ or fullerene C ７０ a photoelectric conversion layer including, as a second organic semiconductor material, any one of tetrathiafulvalene derivatives represented by the following formulas (1-2) to (1-9) having an ionization potential of 0 to 5.0 eV, and a fourth organic semiconductor material having a hole transport property; The photoelectric conversion layer contains the second organic semiconductor material in an amount ranging from 2% to 10% of the volume density of the first organic semiconductor material contained in the photoelectric conversion layer. Photoelectric conversion element. 【Chemistry 1】

2. The photoelectric conversion element according to claim 1 , wherein the photoelectric conversion layer further contains a third organic semiconductor material.

3. The photoelectric conversion element according to claim 2 , wherein the third organic semiconductor material has absorption in a wavelength range of 400 nm or more and 760 nm or less.

4. A plurality of pixels each having one or a plurality of photoelectric conversion elements provided thereon; The photoelectric conversion element is A first electrode; a second electrode disposed opposite the first electrode; A first organic semiconductor material is provided between the first electrode and the second electrode, and fullerene C ６０ or fullerene C ７０ a photoelectric conversion layer including, as a second organic semiconductor material, any one of tetrathiafulvalene derivatives represented by the following formulas (1-2) to (1-9) having an ionization potential of 0 to 5.0 eV, and a fourth organic semiconductor material having a hole transport property; The photoelectric conversion layer contains the second organic semiconductor material in an amount ranging from 2% to 10% of the volume density of the first organic semiconductor material contained in the photoelectric conversion layer. Image sensor. 【Chemistry 2】

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