Method for manufacturing a photoelectric conversion element

Abstract

To provide a method of manufacturing a photoelectric conversion element having higher photoelectric conversion efficiency and higher response characteristics.SOLUTION: A method of manufacturing a photoelectric conversion element disclosed herein includes: forming a first electrode; forming, on the first electrode, a photoelectric conversion layer that includes a chromophore and fullerene or a fullerene derivative through vacuum vapor deposition; forming a second electrode on the photoelectric conversion layer; and bonding between the chromophore and the fullerene or the fullerene derivative via a crosslinking group by heat or light irradiation upon vacuum vapor deposition or by heating or light irradiation after film formation of the photoelectric conversion layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to, for example, a method for producing a photoelectric conversion element using an organic material. [Background technology]

[0002] In imaging elements (organic photoelectric conversion elements) using organic materials, vacuum deposition or coating methods are used to manufacture the organic parts, but the vacuum deposition method is superior in the following respects. First, in the vacuum deposition method, patterning can be easily performed using a metal mask. In addition, in the vacuum deposition method, the organic material, which is the deposition material, is vaporized or sublimated to form a film, so impurities derived from the solvent are not mixed in. Furthermore, since there is no need to dissolve the organic material in a solvent as in the coating method, there is no need to introduce a soluble substituent into the organic material.

[0003] However, there is a demand for improving the photoelectric conversion efficiency of organic photoelectric conversion elements. For example, Patent Document 1 discloses a photoelectric conversion element that uses, as a material for a photoelectric conversion layer, two types of organic materials having different backbones in addition to fullerene or a fullerene derivative, thereby improving the photoelectric conversion efficiency and response characteristics. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 194630 Summary of the Invention [Problem to be solved by the invention]

[0005] Thus, organic photoelectric conversion elements are required to achieve high photoelectric conversion efficiency and response characteristics.

[0006] It would be desirable to provide a method for producing a photoelectric conversion element having excellent photoelectric conversion and response characteristics. [Means for solving the problem]

[0007] A method for producing a photoelectric conversion element according to an embodiment of the present disclosure includes forming a first electrode, forming a photoelectric conversion layer containing a chromophore and a fullerene or a fullerene derivative on the first electrode by a vacuum deposition method, forming a second electrode on the photoelectric conversion layer, and forming a chromophore as a fullerene or a fullerene derivative by heat or light irradiation in the vacuum deposition method or by heating or light irradiation after the formation of the photoelectric conversion layer. Subphthalocyanine, porphyrin, phthalocyanine or derivatives thereof is bonded to a fullerene or a fullerene derivative via a crosslinking group.

[0008] In the manufacturing method of the photoelectric conversion element according to one embodiment of the present disclosure, a photoelectric conversion layer containing a chromophore and a fullerene or a fullerene derivative is formed on a first electrode by vacuum deposition. The chromophore and the fullerene or fullerene derivative in the photoelectric conversion layer are bonded via a crosslinking group by heat or light irradiation during vacuum deposition or by heating or light irradiation after the photoelectric conversion layer is formed. This optimizes the energy level of the fullerene or its derivative, or the orientation of the chromophore and the fullerene or its derivative, improving the electron transfer efficiency or energy transfer efficiency between the chromophore and the fullerene or its derivative. Furthermore, the generation of traps at the interface is suppressed.

[0009] According to the method for producing a photoelectric conversion element according to an embodiment of the present disclosure, a photoelectric conversion layer containing a chromophore and a fullerene or a fullerene derivative is formed on a first electrode by vacuum deposition, and the chromophore and the fullerene or the fullerene derivative in the photoelectric conversion layer are bonded via a crosslinking group by heat or light irradiation during the vacuum deposition method or by heating or light irradiation after the formation of the photoelectric conversion layer, thereby improving the efficiency of electron transfer or energy transfer between the chromophore and the fullerene or its derivative, and suppressing the generation of traps at the interface. Thus, a photoelectric conversion element having excellent photoelectric conversion characteristics and response characteristics can be realized.

[0010] Note that the effects described herein are not necessarily limited to those described above, and may be any of the effects described in this disclosure. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view illustrating a configuration of a photoelectric conversion element according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic diagram showing an example of the structure of a chromophore and a fullerene or a derivative thereof in a photoelectric conversion layer. [Diagram 3] 3 is a schematic diagram showing another example of the structure of a chromophore and a fullerene or a derivative thereof in a photoelectric conversion layer. FIG. [Figure 4] 2 is a plan view showing a configuration of a unit pixel of the photoelectric conversion element shown in FIG. [Diagram 5] 2 is a schematic cross-sectional view for explaining a method for manufacturing the photoelectric conversion element shown in FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a step following FIG. 5. [Figure 7] 2 is a block diagram showing the overall configuration of an image sensor including the photoelectric conversion element shown in FIG. 1. [Figure 8] 8 is a functional block diagram illustrating an example of an imaging device (camera) using the imaging element illustrated in FIG. 7. [Figure 9] 1 is a block diagram showing an example of a schematic configuration of an in-vivo information acquiring system. [Figure 10] 1 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the present technology can be applied. [Figure 11] 11 is a block diagram showing an example of a functional configuration of a camera head and a CCU shown in FIG. 10. FIG. [Figure 12] 1 is a block diagram showing a schematic configuration example of a vehicle control system; [Figure 13] FIG. 4 is an explanatory diagram showing an example of an installation position of an imaging unit. [Figure 14] FIG. 2 is a characteristic diagram showing a change in a vibration peak derived from a crosslinking group before and after annealing in Experimental Example 1. [Figure 15] 1 is a characteristic diagram showing the absorption spectra of a photoelectric conversion layer before and after annealing in Experimental Example 1. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments 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 embodiment. 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. Embodiment (Example of a photoelectric conversion element in which a photoelectric conversion layer containing a chromophore having a crosslinking group, a fullerene or a derivative thereof, and a hole transport material is formed by a vacuum deposition method) 1-1. Photoelectric conversion element configuration 1-2. Manufacturing method of photoelectric conversion element 1-3. Actions and Effects 2. Application Examples 3. Working Example

[0013] <1. Preferred embodiment> FIG. 1 shows a cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 10) according to an embodiment of the present disclosure. The photoelectric conversion element 10 is an imaging element constituting one pixel (unit pixel P) in an imaging device (imaging device 1) such as a back-illuminated (back-illuminated) CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor (see FIG. 7). The photoelectric conversion element 10 is a so-called vertical spectroscopic type in which one organic photoelectric conversion unit 11G and two inorganic photoelectric conversion units 11B and 11R, which selectively detect light in different wavelength ranges and perform photoelectric conversion, are stacked in the vertical direction. The organic photoelectric conversion unit 11G of the present embodiment has a configuration in which a lower electrode 15, a photoelectric conversion layer 16, and an upper electrode 17 are stacked in this order. The photoelectric conversion layer 16, which will be described in detail later, is configured to include a chromophore and a fullerene or a derivative thereof, at least some of which are bonded to each other via a crosslinking group, and a hole transporting material.

[0014] (1-1. Configuration of photoelectric conversion element) The photoelectric conversion element 10 has one organic photoelectric conversion section 11G and two inorganic photoelectric conversion sections 11B and 11R stacked in the vertical direction for each unit pixel P. The organic photoelectric conversion section 11G is provided on the back surface (first surface 11S1) side of the semiconductor substrate 11. The inorganic photoelectric conversion sections 11B and 11R are embedded in the semiconductor substrate 11 and stacked in the thickness direction of the semiconductor substrate 11. The organic photoelectric conversion section 11G includes a photoelectric conversion layer 16 including a p-type semiconductor and an n-type semiconductor and having a bulk heterojunction structure within the layer. The bulk heterojunction structure is a p / n junction surface formed by mixing a p-type semiconductor and an n-type semiconductor.

[0015] The organic photoelectric conversion unit 11G and the inorganic photoelectric conversion units 11B and 11R selectively detect light in different wavelength bands and perform photoelectric conversion. Specifically, the organic photoelectric conversion unit 11G acquires a green (G) color signal. The inorganic photoelectric conversion units 11B and 11R acquire blue (B) and red (R) color signals, respectively, due to differences in absorption coefficients. This makes it possible for the photoelectric conversion element 10 to acquire multiple types of color signals in one pixel without using a color filter.

[0016] In this embodiment, a case where holes among pairs of electrons and holes generated by photoelectric conversion are read out as signal charges (where a p-type semiconductor region is used as a photoelectric conversion layer) will be described. In addition, in the figure, a "+ (plus)" attached to "p" and "n" indicates that the p-type or n-type impurity concentration is high, and "++" indicates that the p-type or n-type impurity concentration is even higher than "+".

[0017] The semiconductor substrate 11 is, for example, made of an n-type silicon (Si) substrate, and has a p-well 61 in a predetermined region. On a second surface (surface of the semiconductor substrate 11) 11S2 of the p-well 61, for example, various floating diffusions (floating diffusion layers) FD (for example, FD1, FD2, FD3), various transistors Tr (for example, a vertical transistor (transfer transistor) Tr1, a transfer transistor Tr2, an amplifier transistor (modulation element) AMP, and a reset transistor RST), and a multi-layer wiring 70 are provided. The multi-layer wiring 70 has, for example, a configuration in which wiring layers 71, 72, 73 are stacked in an insulating layer 74. In addition, a peripheral circuit (not shown) consisting of a logic circuit or the like is provided on the periphery of the semiconductor substrate 11.

[0018] In FIG. 1, the first surface 11S1 side of the semiconductor substrate 11 is represented as a light incident surface S1, and the second surface 11S2 side is represented as a wiring layer side S2.

[0019] The inorganic photoelectric conversion units 11B and 11R are configured, for example, by PIN (Positive Intrinsic Negative) type photodiodes, and each has a pn junction in a predetermined region of the semiconductor substrate 11. The inorganic photoelectric conversion units 11B and 11R are capable of splitting light in the vertical direction by utilizing the fact that the wavelength band absorbed varies depending on the depth of incidence of light in a silicon substrate.

[0020] The inorganic photoelectric conversion unit 11B selectively detects blue light and accumulates signal charges corresponding to blue, and is disposed at a depth capable of efficiently photoelectrically converting blue light. The inorganic photoelectric conversion unit 11R selectively detects red light and accumulates signal charges corresponding to red, and is disposed at a depth capable of efficiently photoelectrically converting red light. Note that blue (B) is a color corresponding to, for example, a wavelength band of 450 nm to 495 nm, and red (R) is a color corresponding to, for example, a wavelength band of 620 nm to 750 nm. Each of the inorganic photoelectric conversion units 11B and 11R may be capable of detecting light in a part or all of the wavelength bands.

[0021] Specifically, as shown in FIG. 1, each of the inorganic photoelectric conversion units 11B and 11R has, for example, a p+ region that serves as a hole accumulation layer and an n region that serves as an electron accumulation layer (having a pnp stacked structure). The n region of the inorganic photoelectric conversion unit 11B is connected to the vertical transistor Tr1. The p+ region of the inorganic photoelectric conversion unit 11B is bent along the vertical transistor Tr1 and connected to the p+ region of the inorganic photoelectric conversion unit 11R.

[0022] As described above, the second surface 11S2 of the semiconductor substrate 11 is provided with, for example, floating diffusions (floating diffusion layers) FD1, FD2, and FD3, a vertical transistor (transfer transistor) Tr1, a transfer transistor Tr2, an amplifier transistor (modulation element) AMP, and a reset transistor RST.

[0023] The vertical transistor Tr1 is a transfer transistor that transfers signal charges (here, holes) corresponding to blue that are generated and accumulated in the inorganic photoelectric conversion unit 11B to the floating diffusion FD1. Since the inorganic photoelectric conversion unit 11B is formed at a deep position from the second surface 11S2 of the semiconductor substrate 11, it is preferable that the transfer transistor of the inorganic photoelectric conversion unit 11B is composed of the vertical transistor Tr1.

[0024] The transfer transistor Tr2 transfers signal charges (here, holes) corresponding to red that are generated and accumulated in the inorganic photoelectric conversion section 11R to the floating diffusion FD2, and is configured by, for example, a MOS transistor.

[0025] The amplifier transistor AMP is a modulation element that modulates the amount of charge generated in the organic photoelectric conversion unit 11G into a voltage, and is configured of, for example, a MOS transistor.

[0026] The reset transistor RST resets the charge transferred from the organic photoelectric conversion section 11G to the floating diffusion FD3, and is composed of, for example, a MOS transistor.

[0027] The lower first contact 75, the lower second contact 76 and the upper contact 13B are made of, for example, a doped silicon material such as PDAS (Phosphorus Doped Amorphous Silicon) or a metal material such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf), tantalum (Ta), etc.

[0028] An organic photoelectric conversion unit 11G is provided on the first surface 11S1 side of the semiconductor substrate 11. The organic photoelectric conversion unit 11G has a configuration in which, for example, a lower electrode 15, a photoelectric conversion layer 16, and an upper electrode 17 are laminated in this order from the first surface S1 side of the semiconductor substrate 11. The lower electrode 15 is formed separately for each unit pixel P, for example. The photoelectric conversion layer 16 and the upper electrode 17 are provided as a continuous layer common to a plurality of unit pixels P (for example, the pixel section 1a of the imaging device 1 shown in FIG. 5). The organic photoelectric conversion unit 11G is an organic photoelectric conversion element that absorbs green light corresponding to a part or all of a wavelength band of a selective wavelength band (for example, 450 nm or more and 650 nm or less) and generates electron-hole pairs.

[0029] Between the first surface 11S1 of the semiconductor substrate 11 and the lower electrode 15, for example, interlayer insulating layers 12 and 14 are laminated in this order from the semiconductor substrate 11 side. The interlayer insulating layer has a configuration in which, for example, a layer (fixed charge layer) 12A having a fixed charge and a dielectric layer 12B having insulating properties are laminated. A protective layer 18 is provided on the upper electrode 17. An on-chip lens layer 19 that constitutes an on-chip lens 19L and also serves as a planarizing layer is provided above the protective layer 18.

[0030] A through electrode 63 is provided between the first surface 11S1 and the second surface 11S2 of the semiconductor substrate 11. The organic photoelectric conversion unit 11G is connected to the gate Gamp of the amplifier transistor AMP and the floating diffusion FD3 via this through electrode 63. This allows the photoelectric conversion element 10 to effectively transfer charges generated in the organic photoelectric conversion unit 11G on the first surface 11S1 side of the semiconductor substrate 11 to the second surface 11S2 side of the semiconductor substrate 11 via the through electrode 63, thereby improving the characteristics.

[0031] The through electrode 63 is provided, for example, for each organic photoelectric conversion unit 11G of the photoelectric conversion element 10. The through electrode 63 functions as a connector between the organic photoelectric conversion unit 11G and the gate Gamp of the amplifier transistor AMP and the floating diffusion FD3, and also serves as a transmission path for charges generated in the organic photoelectric conversion unit 11G.

[0032] The lower end of the through electrode 63 is connected to, for example, a connection portion 71A in the wiring layer 71, and the connection portion 71A and the gate Gamp of the amplifier transistor AMP are connected via a lower first contact 75. The connection portion 71A and the floating diffusion FD3 are connected to the lower electrode 15 via a lower second contact 76. Note that, although the through electrode 63 is shown in FIG. 1 as having a cylindrical shape, the shape is not limited thereto, and may be, for example, a tapered shape.

[0033] It is preferable that the reset gate Grst of the reset transistor RST is disposed next to the floating diffusion FD3, as shown in Fig. 1. This makes it possible to reset the charge accumulated in the floating diffusion FD3 by the reset transistor RST.

[0034] In the photoelectric conversion element 10 of this embodiment, light incident on the organic photoelectric conversion section 11G from the upper electrode 17 side is absorbed by the photoelectric conversion layer 16. The excitons generated by this move to the interface between the electron donor and electron acceptor constituting the photoelectric conversion layer 16, 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 lower electrode 15) and the cathode (here, the upper electrode 17), 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 15 and the upper electrode 17.

[0035] The structure and materials of each part will be described below.

[0036] The organic photoelectric conversion unit 11G is an organic photoelectric conversion element that absorbs light corresponding to a part or all of a selective wavelength band (e.g., 450 nm or more and 750 nm or less) and generates electron-hole pairs. As described above, the organic photoelectric conversion unit 11G is composed of, for example, the lower electrode 15 and the upper electrode 17 arranged opposite to each other, and the photoelectric conversion layer 16 provided between the lower electrode 15 and the upper electrode 17.

[0037] The lower electrode 15 is provided in a region covering the light receiving surfaces of the inorganic photoelectric conversion units 11B and 11R formed in the semiconductor substrate 11, facing directly against the light receiving surfaces. The lower electrode 15 is made of a metal oxide having optical transparency. Examples of metal atoms constituting the metal oxide used as the material of the lower electrode 15 include tin (Sn), zinc (Zn), indium (In), silicon (Si), zirconium (Zr), aluminum (Al), gallium (Ga), tungsten (W), chromium (Cr), cobalt (Co), nickel (Ni), tantalum (Ta), niobium (Nb), and molybdenum (Mo). Examples of metal oxides containing one or more of the above metal atoms include ITO (indium tin oxide). However, in addition to ITO, examples of the material constituting the lower electrode 15 include tin oxide (SnO 2Zinc oxide-based materials may be used, such as aluminum zinc oxide (AZO) with aluminum (Al) added as a dopant, gallium zinc oxide (GZO) with gallium (Ga) added, and indium zinc oxide (IZO) with indium (In) added. In addition to these, CuI, InSbO 4 , ZnMgO, CuInO 2 , MgIn 2 O 4 , CdO, ZnSnO 3 etc. may also be used.

[0038] The photoelectric conversion layer 16 converts light energy into electrical energy, and is configured to include, for example, two or more kinds of organic materials. Specifically, the photoelectric conversion layer 16 is configured to include, for example, a chromophore, a fullerene or a derivative thereof, and a hole transport material. As shown in FIG. 2, for example, among the above three kinds of organic materials, at least a part of the chromophore 161 and the fullerene 162 (or a derivative thereof) is dispersed in the photoelectric conversion layer 16 in a state of being bonded to each other via a crosslinking group. In this embodiment, the fullerene is treated as an organic material.

[0039] The chromophore 161 is an organic molecule that has absorption in the visible light region, and for example, has a wavelength of 50,000 cm at a selective wavelength (e.g., green light of 500 nm or more and 600 nm or less) in the visible light region. -1 The organic photoelectric conversion unit 11G includes a coloring material having an absorption coefficient of 100 nm or more and 600 nm or less. This allows the organic photoelectric conversion unit 11G to selectively convert, for example, green light having a wavelength of 500 nm or more and 600 nm or less into electricity. The chromophore 161 has, for example, a structure in which a conjugated system is linked in a chain or ring shape, and has, for example, a molecular structure in which two or more five-membered or six-membered rings are linked. The chromophore 161 has a crosslinking group 161X in the molecule, and although details will be described later, the chromophore 161 is an organic material in which the change in absorption peak wavelength is small before and after bonding with the fullerene 162 (or a derivative thereof) via the crosslinking group 161X, specifically, within ±10 nm.

[0040] Examples of such organic materials include subphthalocyanine, porphyrin, phthalocyanine, dipyrromethane, azadipyrromethane, dipyridyl, azadipyridyl, coumarin, perylene, perylene diimide, pyrene, naphthalene diimide, quinacridone, xanthene, xanthenoxanthene, phenoxazine, indigo, azooxazine, benzodithiophene, naphthodithiophene, anthradithiophene, rubicene, anthracene, tetracene, pentacene, anthraquinone, tetraquinone, pentaquinone, dinaphthothienothiophene, diketopyrrolopyrrole, oligothiophene, cyanine, squalium, croconium, and derivatives thereof, as shown in the following formulas (1-1) to (1-40).

[0041] [ka]

[0042] [ka]

[0043] [ka]

[0044] [ka]

[0045] In the above formulae (1-1) to (1-40), X is a position where a crosslinking group 161X can be introduced, and the crosslinking group 161X capable of bonding to a fullerene or a derivative thereof is introduced at one or more positions. In addition, the organic materials shown in the above formulae (1-1) to (1-40) may have X's together forming a ring, with the crosslinking group 161X sandwiched between the rings. M is a metal atom. n is an integer of 1 to 8.

[0046] The bridging group 161X includes a conjugated diene, and examples thereof include benzene, naphthalene, anthracene, tetracene, pentacene, cyclopentadiene, indene, furan, thiophene, benzofuran, benzothiophene, and 1,3-butadiene, as shown in the following formulas (X-1) to (X-24). The type and position of the chemical bond between the chromophore 161 and the bridging group 161X are not particularly limited. In addition, for example, a straight-chain alkyl group, a branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an ether bond, a thioether bond, an amino group, an acyl group, an ester bond, an amide bond, a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group, a thienyl group, a bithienyl group, a thienylphenyl group, a furyl group, a pyrrole group, a benzothienyl group, a benzofuran group, an indole group, and an indene group may be mediated.

[0047] [ka]

[0048] [ka]

[0049] In addition to the bridging group 161X, X may each independently introduce a hydrogen atom, a halogen atom, a linear, branched, or cyclic alkyl group, a thioalkyl group, a thioaryl group, an arylsulfonyl group, an alkylsulfonyl group, an amino group, an alkylamino group, an arylamino group, a hydroxyl group, an alkoxy group, an acylamino group, an acyloxy group, a phenyl group, a carboxy group, a carboxamido group, a carboalkoxy group, an acyl group, a sulfonyl group, a cyano group, and a nitro group, or a derivative thereof. Also, as described above, any adjacent X may be a part of a condensed aliphatic ring or a condensed aromatic ring. The condensed aliphatic ring or the condensed aromatic ring may contain one or more atoms other than carbon.

[0050] The fullerene 162 or a derivative thereof functions as, for example, an electron transport material in the photoelectric conversion layer 16. As the fullerene or a derivative thereof, for example, C 60 Fullerene and C shown in formula (2-2) 70 Fullerenes are an example.

[0051] [ka]

[0052] 2 shows an example in which the chromophore 161 and the fullerene 162 are bonded in a 1:1 ratio with the crosslinking group 161X interposed therebetween, but the present invention is not limited to this. For example, as shown in FIG. 3, two or more molecules of the chromophore 161 may be bonded to one molecule of the fullerene 162 or its derivative via the crosslinking group 161X. Alternatively, a plurality of fullerenes 162 or their derivatives may be bonded to one molecule of the chromophore 161 via the crosslinking group 161X.

[0053] In addition, the photoelectric conversion layer 16 is preferably configured to include one or more organic materials having a hole transporting property. The organic material having a hole transporting property preferably has a HOMO (Highest Occupied Molecular Orbital) level higher than that of the fullerene 162 or a derivative thereof. Examples of the organic material having a hole transporting property include compounds shown in the following formulae (3-1) to (3-11). Other examples of the hole transporting material include triarylamine derivatives (TPD, NPB, TAPC, etc.), carbazole derivatives (CBP, TCTA, etc.), and fluorene derivatives (BSBF, etc.).

[0054] [ka]

[0055] The photoelectric conversion layer 16 has a junction surface (p / n junction surface) between a p-type semiconductor and an n-type semiconductor within the layer. The p-type semiconductor functions relatively as an electron donor (donor), and the n-type semiconductor functions relatively as an electron acceptor (acceptor). The photoelectric conversion layer 16 provides a field where excitons generated upon absorbing light are separated into electrons and holes, and the excitons are separated into electrons and holes at the interface (p / n junction surface) between the electron donor and electron acceptor. The thickness of the photoelectric conversion layer 16 is, for example, 50 nm to 500 nm.

[0056] The upper electrode 17 is made of a conductive film having optical transparency, similar to the lower electrode 15. In the photoelectric conversion element 10, the upper electrode 17 may be separated for each unit pixel P, or may be formed as a common electrode for each unit pixel P. The thickness of the upper electrode 17 is, for example, 10 nm to 200 nm.

[0057] Other layers may be provided between the photoelectric conversion layer 16 and the lower electrode 15, and between the photoelectric conversion layer 16 and the upper electrode 17. Specifically, for example, an undercoat layer, a hole transport layer, an electron blocking layer, the photoelectric conversion layer 16, a hole blocking layer, a buffer layer, an electron transport layer, and a work function adjustment layer may be laminated in this order from the lower electrode 15 side.

[0058] The fixed charge layer 12A may be a film having a positive fixed charge or a film having a negative fixed charge. Examples of materials for a film having a negative fixed charge include hafnium oxide (HfO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), tantalum oxide (Ta 2 O 5 ), titanium dioxide (TiO 2In addition, materials other than those mentioned above include lanthanum oxide, praseodymium oxide, cerium oxide, neodymium oxide, promethium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium oxide, thulium oxide, ytterbium oxide, lutetium oxide, yttrium oxide, an aluminum nitride film, a hafnium oxynitride film, an aluminum oxynitride film, and the like may be used.

[0059] The fixed charge layer 12A may have a structure in which two or more types of films are laminated together, which can further enhance the function as a hole accumulation layer, for example, in the case of a film having a negative fixed charge.

[0060] The material of the dielectric layer 12B is not particularly limited, but it may be formed of, for example, a silicon oxide film, a TEOS film, a silicon nitride film, a silicon oxynitride film, or the like.

[0061] The interlayer insulating layer 14 is, for example, a single layer film made of one of silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), etc., or a laminated film made of two or more of these materials.

[0062] The protective layer 18 is made of a light-transmitting material, and is, for example, a single layer film made of any one of silicon oxide, silicon nitride, silicon oxynitride, etc., or a laminated film made of two or more of these materials. The thickness of this protective layer 18 is, for example, 100 nm to 30,000 nm.

[0063] On the protective layer 18, an on-chip lens layer 19 is formed so as to cover the entire surface. A plurality of on-chip lenses 19L (microlenses) are provided on the surface of the on-chip lens layer 19. The on-chip lenses 19L focus light incident from above onto the light receiving surfaces of the organic photoelectric conversion unit 11G and the inorganic photoelectric conversion units 11B and 11R. In this embodiment, since the multilayer wiring 70 is formed on the second surface 11S2 side of the semiconductor substrate 11, the light receiving surfaces of the organic photoelectric conversion unit 11G and the inorganic photoelectric conversion units 11B and 11R can be arranged close to each other, and the variation in sensitivity between colors that occurs depending on the F value of the on-chip lenses 19L can be reduced.

[0064] Fig. 4 is a plan view showing an example of the configuration of a photoelectric conversion element 10 in which a plurality of photoelectric conversion units (e.g., the inorganic photoelectric conversion units 11B and 11R and the organic photoelectric conversion unit 11G) to which the technology according to the present disclosure can be applied are stacked. That is, Fig. 4 shows, for example, an example of the planar configuration of a unit pixel P constituting the pixel unit 1a shown in Fig. 7.

[0065] The unit pixel P has a photoelectric conversion region 1100 in which a red photoelectric conversion unit (inorganic photoelectric conversion unit 11R in FIG. 1), a blue photoelectric conversion unit (inorganic photoelectric conversion unit 11B in FIG. 1), and a green photoelectric conversion unit (organic photoelectric conversion unit 11G in FIG. 1) (none of which are shown in FIG. 4) that photoelectrically convert light of the respective wavelengths of R (Red), G (Green), and B (Blue) are stacked in three layers, for example, in the order of the green photoelectric conversion unit, the blue photoelectric conversion unit, and the red photoelectric conversion unit, from the light receiving surface (light incident surface S1 in FIG. 1). Furthermore, the unit pixel P has a Tr group 1110, a Tr group 1120, and a Tr group 1130 as charge readout units that read out charges corresponding to light of the respective wavelengths of RGB from the red photoelectric conversion unit, the green photoelectric conversion unit, and the blue photoelectric conversion unit. In the imaging device 1, in one unit pixel P, separation in the vertical direction, i.e., separation of each of the R, G and B lights is performed in each layer serving as a red photoelectric conversion unit, a green photoelectric conversion unit, and a blue photoelectric conversion unit stacked in the photoelectric conversion region 1100.

[0066] The Tr group 1110, the Tr group 1120, and the Tr group 1130 are formed around the photoelectric conversion region 1100. The Tr group 1110 outputs a signal charge corresponding to R light generated and accumulated in the red photoelectric conversion unit as a pixel signal. The Tr group 1110 is composed of a transfer Tr (MOS FET) 1111, a reset Tr 1112, an amplifier Tr 1113, and a selection Tr 1114. The Tr group 1120 outputs a signal charge corresponding to B light generated and accumulated in the blue photoelectric conversion unit as a pixel signal. The Tr group 1120 is composed of a transfer Tr 1121, a reset Tr 1122, an amplifier Tr 1123, and a selection Tr 1124. The Tr group 1130 outputs a signal charge corresponding to G light generated and accumulated in the green photoelectric conversion unit as a pixel signal. The Tr group 1130 is made up of a transfer Tr 1131 , a reset Tr 1132 , an amplifier Tr 1133 and a selection Tr 1134 .

[0067] Transfer Tr 1111 is composed of a gate G, a source / drain region S / D, and an FD (floating diffusion) 1115 (a source / drain region serving as the same). Transfer Tr 1121 is composed of a gate G, a source / drain region S / D, and an FD 1125. Transfer Tr 1131 is composed of a gate G, a green photoelectric conversion unit (a source / drain region S / D connected to the same) in the photoelectric conversion region 1100, and an FD 1135. The source / drain region of transfer Tr 1111 is connected to a red photoelectric conversion unit in the photoelectric conversion region 1100, and the source / drain region S / D of transfer Tr 1121 is connected to a blue photoelectric conversion unit in the photoelectric conversion region 1100.

[0068] The reset Tr 1112, 1132, and 1122, the amplifying Tr 1113, 1133, and 1123, and the selecting Tr 1114, 1134, and 1124 are each composed of a gate G and a pair of source / drain regions S / D arranged so as to sandwich the gate G therebetween.

[0069] The FDs 1115, 1135, and 1125 are connected to the source / drain regions S / D which form the sources of the reset Tr 1112, 1132, and 1122, respectively, and are also connected to the gates G of the amplifier Tr 1113, 1133, and 1123, respectively. A power supply Vdd is connected to the source / drain regions S / D common to the reset Tr 1112 and the amplifier Tr 1113, the reset Tr 1132 and the amplifier Tr 1133, and the reset Tr 1122 and the amplifier Tr 1123. A VSL (vertical signal line) is connected to the source / drain regions S / D which form the sources of the selection Tr 1114, 1134, and 1124.

[0070] The technology according to the present disclosure can be applied to the above-described photoelectric conversion element.

[0071] (1-2. Method for manufacturing photoelectric conversion element) The photoelectric conversion element 10 of the present embodiment can be manufactured, for example, as follows.

[0072] 5 and 6 show the manufacturing method of the photoelectric conversion element 10 in the order of steps. First, as shown in Fig. 5, for example, a p-well 61 is formed as a first conductivity type well in the semiconductor substrate 11, and inorganic photoelectric conversion units 11B, 11R of a second conductivity type (for example, n-type) are formed in this p-well 61. A p+ region is formed in the vicinity of the first surface 11S1 of the semiconductor substrate 11.

[0073] 5, n+ regions that become floating diffusions FD1 to FD3 are formed on the second surface 11S2 of the semiconductor substrate 11, and then a gate insulating layer 62 and a gate wiring layer 64 including the gates of the vertical transistor Tr1, the transfer transistor Tr2, the amplifier transistor AMP, and the reset transistor RST are formed. This forms the vertical transistor Tr1, the transfer transistor Tr2, the amplifier transistor AMP, and the reset transistor RST. Furthermore, a multilayer wiring 70 including a lower first contact 75, a lower second contact 76, wiring layers 71 to 73 including a connection portion 71A, and an insulating layer 74 is formed on the second surface 11S2 of the semiconductor substrate 11.

[0074] As the base of the semiconductor substrate 11, for example, an SOI (Silicon on Insulator) substrate in which the semiconductor substrate 11, a buried oxide film (not shown), and a holding substrate (not shown) are laminated is used. Although not shown in Fig. 5, the buried oxide film and the holding substrate are bonded to the first surface 11S1 of the semiconductor substrate 11. After the ion implantation, an annealing process is performed.

[0075] Next, a support substrate (not shown) or another semiconductor substrate is bonded to the second surface 11S2 side (the multilayer wiring 70 side) of the semiconductor substrate 11, and the substrate is turned upside down. Next, the semiconductor substrate 11 is separated from the buried oxide film of the SOI substrate and the holding substrate, and the first surface 11S1 of the semiconductor substrate 11 is exposed. The above steps can be performed by techniques used in normal CMOS processes, such as ion implantation and CVD (Chemical Vapor Deposition).

[0076] 6, the semiconductor substrate 11 is processed from the first surface 11S1 side by, for example, dry etching to form an annular opening 63H. As shown in FIG. 6, the depth of the opening 63H penetrates from the first surface 11S1 to the second surface 11S2 of the semiconductor substrate 11 and reaches, for example, the connection portion 71A.

[0077] 6, for example, a negative fixed charge layer 12A is formed on the first surface 11S1 of the semiconductor substrate 11 and the side surface of the opening 63H. The negative fixed charge layer 12A may be formed by stacking two or more types of films. This makes it possible to further improve the function as a hole accumulation layer. After forming the negative fixed charge layer 12A, a dielectric layer 12B is formed.

[0078] Next, a conductor is embedded in the opening 63H to form the through electrode 63. As the conductor, for example, a doped silicon material such as PDAS (Phosphorus Doped Amorphous Silicon) or a metal material such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf), and tantalum (Ta) can be used.

[0079] Next, after forming a pad portion 13A on the through electrode 63, an interlayer insulating layer 14 is formed on the dielectric layer 12B and the pad portion 13A, in which an upper contact 13B and a pad portion 13C are provided on the pad portion 13A to electrically connect the lower electrode 15 and the through electrode 63 (specifically, the pad portion 13A on the through electrode 63).

[0080] Next, the lower electrode 15, the photoelectric conversion layer 16, the upper electrode 17, and the protective layer 18 are formed in this order on the interlayer insulating layer 14. The photoelectric conversion layer 16 is formed by, for example, forming a film of the above-mentioned chromophore 161, fullerene 162 (or a derivative thereof), and a hole transport material using, for example, a vacuum deposition method. At least a part of the chromophore 161 and the fullerene 162 (or a derivative thereof) are bonded via a crosslinking group by heat or light irradiation during film formation or by heating or light irradiation after film formation. Finally, an on-chip lens layer 19 having a plurality of on-chip lenses 19L on its surface is disposed. With the above steps, the photoelectric conversion element 10 shown in FIG. 1 is completed.

[0081] As described above, when another organic layer (e.g., an electron blocking layer, etc.) is formed above or below the photoelectric conversion layer 16, it is desirable to form it continuously in a vacuum process (through a vacuum integrated process). In addition, the method of forming the photoelectric conversion layer 16 is not necessarily limited to a method using a vacuum deposition method, and other methods, such as a spin coating technique or a printing technique, may also be used.

[0082] In the photoelectric conversion element 10, when light is incident on the organic photoelectric conversion unit 11G through the on-chip lens 19L, the light passes through the organic photoelectric conversion unit 11G, the inorganic photoelectric conversion units 11B and 11R in this order, and is photoelectrically converted into green, blue, and red light during the passing process. The signal acquisition operation for each color will be described below.

[0083] (Acquisition of a green signal by the organic photoelectric conversion unit 11G) Of the light incident on the photoelectric conversion element 10, green light is first selectively detected (absorbed) in the organic photoelectric conversion section 11G and photoelectrically converted.

[0084] The organic photoelectric conversion unit 11G is connected to the gate Gamp of the amplifier transistor AMP and the floating diffusion FD3 via the through electrode 63. Thus, the holes of the electron-hole pairs generated in the organic photoelectric conversion unit 11G are extracted from the lower electrode 15 side, transferred to the second surface 11S2 side of the semiconductor substrate 11 via the through electrode 63, and accumulated in the floating diffusion FD3. At the same time, the amount of charge generated in the organic photoelectric conversion unit 11G is modulated into a voltage by the amplifier transistor AMP.

[0085] In addition, a reset gate Grst of the reset transistor RST is disposed next to the floating diffusion FD3, so that the charge accumulated in the floating diffusion FD3 is reset by the reset transistor RST.

[0086] Here, the organic photoelectric conversion unit 11G is connected not only to the amplifier transistor AMP but also to the floating diffusion FD3 via the through electrode 63, so that the charge accumulated in the floating diffusion FD3 can be easily reset by the reset transistor RST.

[0087] On the other hand, if the through electrode 63 and the floating diffusion FD3 are not connected, it becomes difficult to reset the charge accumulated in the floating diffusion FD3, and a large voltage is applied to pull it out to the upper electrode 17 side. This may damage the photoelectric conversion layer 16. In addition, a structure that enables resetting in a short time leads to an increase in dark noise, which is a trade-off, and therefore this structure is difficult to implement.

[0088] (Acquisition of blue and red signals by inorganic photoelectric conversion units 11B and 11R) Next, of the light transmitted through the organic photoelectric conversion unit 11G, the blue light is absorbed in the inorganic photoelectric conversion unit 11B, and the red light is absorbed in the inorganic photoelectric conversion unit 11R, in that order, and photoelectrically converted. In the inorganic photoelectric conversion unit 11B, electrons corresponding to the incident blue light are accumulated in the n-region of the inorganic photoelectric conversion unit 11B, and the accumulated electrons are transferred to the floating diffusion FD1 by the vertical transistor Tr1. Similarly, in the inorganic photoelectric conversion unit 11R, electrons corresponding to the incident red light are accumulated in the n-region of the inorganic photoelectric conversion unit 11R, and the accumulated electrons are transferred to the floating diffusion FD2 by the transfer transistor Tr2.

[0089] (1-3. Actions and Effects) As mentioned above, the manufacturing method of the organic part of the organic photoelectric conversion element can be roughly divided into vacuum deposition method and coating method. Of these, the vacuum deposition method can easily perform patterning by using a metal mask. In addition, the vacuum deposition method forms a film by vaporizing or sublimating the deposition material v, so impurities derived from the solvent are not mixed in. Furthermore, since there is no need to dissolve the organic material in a solvent as in the coating method, there is an advantage that there is no need to introduce a soluble substituent into the organic material.

[0090] Incidentally, in the case of organic photoelectric conversion elements, photoelectric conversion layers that combine dyes and fullerenes have been widely studied. However, assuming that the photoelectric conversion layer is formed using a vacuum deposition method as a manufacturing method, the following problems are raised.

[0091] First, although it is possible to control the energy state of fullerenes by introducing substituents, and the open circuit voltage (Voc) can be improved, fullerenes with substituents introduced therein are at risk of decomposing during vacuum deposition, making it difficult to establish a stable manufacturing process.

[0092] Secondly, in order to obtain high photoelectric conversion efficiency in an organic photoelectric conversion element using fullerene, the distance and orientation between the dye and fullerene in the photoelectric conversion layer are important, and a method of directly linking the dye and fullerene is considered as a method of controlling this. However, a molecule in which two skeletons are directly linked may decompose during vacuum deposition, as with the fullerene with the above-mentioned substituent introduced, and there is a problem that it is difficult to establish a stable manufacturing process.

[0093] As a method for solving the above problem, for example, the Dields-Alder reaction is used to form C after deposition. 60 Methods for introducing substituents into fullerenes have been proposed. However, the Dields-Alder reaction opens the ring structure responsible for absorbing visible light in the dye, resulting in a decrease in the amount of visible light absorbed and a decrease in light-harvesting efficiency.

[0094] In contrast, in the present embodiment, a photoelectric conversion layer 16 is formed that contains a chromophore, a fullerene or a derivative thereof, and a hole transport material, and in which a part of the chromophore 161 and a fullerene 162 or a derivative thereof are bonded via a bridging group 161X. This optimizes the energy level of the fullerene or a derivative thereof, or the orientation of the chromophore and the fullerene or a derivative thereof, thereby improving the efficiency of electron transfer or energy transfer between the chromophore and the fullerene or a derivative thereof. Furthermore, it is possible to suppress the generation of traps at the interface.

[0095] As described above, in the photoelectric conversion element 10 and the manufacturing method thereof according to the present embodiment, the photoelectric conversion layer 16 is formed including the chromophore 161 and the fullerene 162 or a derivative thereof, at least some of which are bonded to each other via the crosslinking group 161X, and a hole transport material. This optimizes the energy level of the fullerene or a derivative thereof, or the orientation of the chromophore and the fullerene or a derivative thereof. This improves the electron transfer efficiency or energy transfer efficiency between the chromophore and the fullerene or a derivative thereof, and suppresses the generation of traps at the interface. This makes it possible to realize a photoelectric conversion element having excellent photoelectric conversion characteristics and response characteristics.

[0096] In addition, the photoelectric conversion layer 16 can be formed by vacuum deposition without decomposing the fullerene or its derivatives or opening the ring of the dye that constitutes the chromophore, which allows the manufacturing process to be simplified and a stable manufacturing process to be established.

[0097] <2. Application Examples> (Application example 1) 7 shows the overall configuration of an imaging device 1 in which, for example, the photoelectric conversion element 10 described in the above embodiment is used for each pixel. The imaging device 1 is a CMOS image sensor, and has a pixel section 1a as an imaging area on a semiconductor substrate 11, and also has a peripheral circuit section 130 in the peripheral region of the pixel section 1a, which includes, for example, a row scanning section 131, a horizontal selection section 133, a column scanning section 134, and a system control section 132.

[0098] The pixel section 1a has a plurality of unit pixels P (e.g., equivalent to photoelectric conversion elements 10) 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 row scanning section 131 corresponding to each row.

[0099] The row scanning unit 131 is a pixel driving unit that is configured with a shift register, an address decoder, etc., and drives each unit pixel P of the pixel unit 1a, for example, row by row. A signal output from each unit pixel P of a pixel row selected and scanned by the row scanning unit 131 is supplied to the horizontal selection unit 133 through each vertical signal line Lsig. The horizontal selection unit 133 is configured with an amplifier, a horizontal selection switch, etc., provided for each vertical signal line Lsig.

[0100] The column scanning unit 134 is composed of a shift register, an address decoder, etc., and sequentially drives while scanning each horizontal selection switch of the horizontal selection unit 133. By the selective scanning by this column scanning unit 134, the signals of each pixel transmitted through each vertical signal line Lsig are output in sequence to a horizontal signal line 135, and transmitted to the outside of the semiconductor substrate 11 through the horizontal signal line 135.

[0101] A circuit portion consisting of row scanning section 131, horizontal selection section 133, column scanning section 134, and horizontal signal line 135 may be formed directly on semiconductor substrate 11, 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.

[0102] The system control unit 132 receives a clock and data instructing an operation mode provided from outside the semiconductor substrate 11, and also outputs data such as internal information of the imaging device 1. The system control unit 132 further has a timing generator that generates various timing signals, and performs drive control of peripheral circuits such as the row scanning unit 131, horizontal selection unit 133, and column scanning unit 134 based on the various timing signals generated by the timing generator.

[0103] (Application example 2) The above-mentioned imaging device 1 can be applied to any type of electronic device equipped with an imaging function, such as a camera system such as a digital still camera or video camera, or a mobile phone with an imaging function. As an example, Fig. 8 shows a schematic configuration of a camera 2. The camera 2 is, for example, a video camera capable of taking still or moving images, and includes the imaging device 1, an optical system (optical lens) 310, a shutter device 311, a drive unit 313 that drives the imaging device 1 and the shutter device 311, and a signal processing unit 312.

[0104] The optical system 310 guides image light (incident light) from a subject to the pixel section 1a of the imaging device 1. This optical system 310 may be composed of a plurality of optical lenses. The shutter device 311 controls the light irradiation period and the light blocking period of the imaging device 1. The drive section 313 controls the transfer operation of the imaging device 1 and the shutter operation of the shutter device 311. The signal processing section 312 performs various signal processing on the signal output from the imaging device 1. The video signal Dout after the signal processing is stored in a storage medium such as a memory, or is output to a monitor, etc.

[0105] (Application example 3) <Application example to in-body information acquisition system> Furthermore, 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.

[0106] FIG. 9 is a block diagram showing an example of a schematic configuration of a patient's in-vivo information acquisition system using a capsule endoscope to which the technology according to the present disclosure (the present technology) can be applied.

[0107] The in-vivo information acquisition system 10001 includes a capsule endoscope 10100 and an external control device 10200 .

[0108] The capsule endoscope 10100 is swallowed by a patient during an examination. The capsule endoscope 10100 has an imaging function and a wireless communication function, and while moving inside an organ such as the stomach or intestines by peristalsis or the like until it is naturally discharged from the patient, sequentially captures images of the inside of the organ (hereinafter also referred to as in-vivo images) at predetermined intervals, and sequentially wirelessly transmits information about the in-vivo images to an external control device 10200 outside the body.

[0109] The external control device 10200 comprehensively controls the operation of the in-vivo information acquisition system 10001. In addition, the external control device 10200 receives information about the in-vivo image transmitted from the capsule endoscope 10100, and generates image data for displaying the in-vivo image on a display device (not shown) based on the received information about the in-vivo image.

[0110] In this manner, the in-vivo information acquiring system 10001 can obtain in-vivo images capturing images of the state inside the patient's body at any time from when the capsule endoscope 10100 is swallowed to when it is expelled.

[0111] The configurations and functions of the capsule endoscope 10100 and the external control device 10200 will be described in more detail.

[0112] The capsule endoscope 10100 has a capsule-shaped housing 10101, which houses a light source unit 10111, an imaging unit 10112, an image processing unit 10113, a wireless communication unit 10114, a power supply unit 10115, a power supply unit 10116, and a control unit 10117.

[0113] The light source unit 10111 is composed of a light source such as an LED (light emitting diode), and irradiates the imaging field of the imaging unit 10112 with light.

[0114] The imaging unit 10112 is composed of an imaging element and an optical system consisting of multiple lenses provided in front of the imaging element. Reflected light (hereinafter referred to as observation light) of light irradiated onto the body tissue to be observed is collected by the optical system and enters the imaging element. In the imaging unit 10112, the imaging element photoelectrically converts the observation light incident thereon, and generates an image signal corresponding to the observation light. The image signal generated by the imaging unit 10112 is provided to an image processing unit 10113.

[0115] The image processing unit 10113 is configured with a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and performs various signal processing on the image signal generated by the imaging unit 10112. The image processing unit 10113 provides the image signal after the signal processing to the wireless communication unit 10114 as RAW data.

[0116] The wireless communication unit 10114 performs predetermined processing such as modulation processing on the image signal that has been subjected to signal processing by the image processing unit 10113, and transmits the image signal to the external control device 10200 via the antenna 10114A. The wireless communication unit 10114 also receives a control signal related to drive control of the capsule endoscope 10100 from the external control device 10200 via the antenna 10114A. The wireless communication unit 10114 provides the control signal received from the external control device 10200 to the control unit 10117.

[0117] The power supply unit 10115 is composed of an antenna coil for receiving power, a power regeneration circuit for regenerating power from a current generated in the antenna coil, a boost circuit, etc. In the power supply unit 10115, power is generated using the principle of so-called non-contact charging.

[0118] The power supply unit 10116 is composed of a secondary battery, and stores the power generated by the power supply unit 10115. In order to avoid cluttering the drawing, arrows and other symbols indicating the destination of the power supply from the power supply unit 10116 are omitted in Fig. 9, but the power stored in the power supply unit 10116 is supplied to the light source unit 10111, the imaging unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the control unit 10117 and can be used to drive these units.

[0119] The control unit 10117 is composed of a processor such as a CPU, and appropriately controls the driving of the light source unit 10111, the imaging unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the power supply unit 10115 in accordance with control signals transmitted from the external control device 10200.

[0120] The external control device 10200 is composed of a processor such as a CPU or a GPU, or a microcomputer or a control board in which a processor and a storage element such as a memory are mixed. The external control device 10200 controls the operation of the capsule endoscope 10100 by transmitting a control signal to the control unit 10117 of the capsule endoscope 10100 via the antenna 10200A. In the capsule endoscope 10100, for example, the light irradiation conditions for the observation target in the light source unit 10111 can be changed by the control signal from the external control device 10200. Furthermore, the imaging conditions (for example, the frame rate and exposure value in the imaging unit 10112) can be changed by the control signal from the external control device 10200. Furthermore, the content of the processing in the image processing unit 10113 and the conditions for the wireless communication unit 10114 to transmit an image signal (for example, the transmission interval, the number of transmitted images, etc.) may be changed by the control signal from the external control device 10200.

[0121] The external control device 10200 also applies various image processing to the image signal transmitted from the capsule endoscope 10100 to generate image data for displaying the captured in-vivo image on a display device. As the image processing, various signal processing such as development processing (demosaic processing), image quality improvement processing (band enhancement processing, super-resolution processing, NR (Noise reduction) processing, and / or image stabilization processing, etc.) and / or enlargement processing (electronic zoom processing) can be performed. The external control device 10200 controls the driving of the display device to display the captured in-vivo image based on the generated image data. Alternatively, the external control device 10200 may record the generated image data in a recording device (not shown) or print out the image data on a printing device (not shown).

[0122] An example of an in-vivo information acquisition 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, for example, the imaging unit 10112 of the above-described configuration. This improves detection accuracy.

[0123] (Application example 4) <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.

[0124] FIG. 10 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.

[0125] 10 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] FIG. 11 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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 .

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] (Application example 5) <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.

[0157] FIG. 12 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.

[0158] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 12, 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.

[0159] 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.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] 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. 12, 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.

[0168] FIG. 13 is a diagram showing an example of the installation position of the imaging unit 12031.

[0169] In FIG. 13, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0170] 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.

[0171] 13 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.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] <3. Examples> Next, an embodiment of the present disclosure will be described in detail.

[0177] (Experiment 1) In Experiment 1, photoelectric conversion elements using chromophores having a crosslinking group in the molecule as Experimental Examples 1 and 2, and a photoelectric conversion element using a dye having no crosslinking group in the molecule as Experimental Example 3 were prepared, and their external quantum efficiency (EQE) and open circuit voltage (Voc) were evaluated.

[0178] First, the product obtained by the following scheme is purified by sublimation to obtain the chromophore of the present disclosure, represented by formula (1-1-6): 6 Using the same method, F represented by the following formula (4-1) having a crosslinking group in the molecule was obtained. 6 -SubPc-O-Ph-26F 2 and F represented by formula (4-2) having no bridging group in the molecule. 6 -SubPc-F was obtained.

[0179] [ka]

[0180] [ka]

[0181] (Experimental Example 1) A 100 nm thick ITO film was formed on a quartz substrate using a sputtering device. This ITO film was patterned by photolithography and etching to form an ITO electrode (lower electrode). The quartz substrate with the ITO electrode was then cleaned by UV / ozone treatment, after which the quartz substrate was transferred to a vacuum deposition machine and 1×10 -5 While rotating the substrate holder under reduced pressure of 0 Pa or less, the PC-IC shown in the following formula (5) was deposited on the quartz substrate at a substrate temperature of 0°C to a thickness of 10 nm to form an electron blocking layer. 6 -SubPc-O-2AN, DPh-BTBT shown in the following formula (6), and C 60 Fullerene was deposited at a substrate temperature of 40° C. at deposition rates of 0.50 Å / sec, 0.50 Å / sec, and 0.25 Å / sec, respectively, so that the mixed layer had a thickness of 230 nm, forming a photoelectric conversion layer. Next, NDI-35 shown in the following formula (7) was deposited at a substrate temperature of 0° C. to a thickness of 10 nm, forming a hole blocking layer. Finally, the quartz substrate was transferred to a sputtering device, and an ITO film was deposited on the hole blocking layer to a thickness of 50 nm, forming an upper electrode. By the above-mentioned fabrication method, a photoelectric conversion element (Experimental Example 1) having a photoelectric conversion area of ​​1 mm×1 mm was fabricated.

[0182] [ka]

[0183] (Experimental Example 2) F used in Experimental Example 1 6 -SubPc-O-2AN (formula (1-1-16)) instead of F shown in the above formula (4-1) 6 -SubPc-O-Ph-26F 2A photoelectric conversion element (Experimental Example 2) was produced in the same manner as in Experimental Example 1, except that the following was used.

[0184] (Experimental Example 3) F used in Experimental Example 1 6 -SubPc-O-2AN (formula (1-1-16)) instead of F shown in the above formula (4-2) 6 A photoelectric conversion element (Experimental Example 3) was produced in the same manner as in Experimental Example 1, except that -SubPc-F was used.

[0185] The external quantum efficiency (EQE), open circuit voltage (Voc), form factor (ff) and photoelectric conversion efficiency (η) of Experimental Examples 1 to 3 were evaluated using the following methods. The results are summarized in Table 1 together with the chromophore (dye) used in each Experimental Example.

[0186] The wavelength of light irradiated from a green LED light source through a bandpass filter onto the photoelectric conversion element is 560 nm, and the light intensity is 1.62 μW / cm 2 A semiconductor parameter analyzer was used to control the bias voltage applied between the electrodes of the photoelectric conversion element, and the voltage applied to the lower electrode relative to the upper electrode was swept to obtain a current-voltage curve. The light current and dark current values ​​in the short-circuit state were measured to calculate the EQE. The open circuit voltage (Voc) was calculated from the voltage in the open circuit state. The photoelectric conversion efficiency (η) was calculated by dividing the maximum power in the current-voltage curve by the irradiation energy of green light. The form factor (ff) was calculated by dividing the photoelectric conversion efficiency (η) by the product of the short-circuit state current and the open circuit voltage (Voc).

[0187] (Chromophore (or dye) and C 60 Evaluation of reaction products with fullerene) The chromophore (or dye) and C used in Experimental Examples 1 to 3 were deposited on a silicon substrate using a vacuum deposition machine. 60A mixed film with a ratio of 2:1 to fullerene was formed to a thickness of 150 nm, and gold (Au) was evaporated onto the mixed film to a thickness of 100 nm to prepare evaluation samples. Evaluation samples that were not annealed and evaluation samples that were annealed at 150°C in a nitrogen-substituted atmosphere were prepared. Infrared light was irradiated onto each evaluation sample from the silicon substrate side, and high-sensitivity reflection infrared spectroscopy (IRRAS) was measured by multiple reflection of the infrared light between the Au and the substrate. The presence or absence of changes in the vibration peaks derived from the crosslinking groups before and after annealing from the changes in the IRRAS spectrum allowed the determination of the chromophore (or dye) and C 60 The presence or absence of reaction products with fullerene was confirmed.

[0188] [Table 1]

[0189] F used in Experimental Example 1 6 As can be seen from formula (1-1-16), -SubPc-O-2AN has a structure in which a conjugated diene bridging group is introduced into the subphthalocyanine chromophore. 6 -SubPc-O-2AN and C 60 As shown in Figure 14, the photoelectric conversion layer containing fullerene showed a change in the vibration peak derived from the crosslinking group before and after annealing using high-sensitivity infrared reflection spectroscopy. 60 It was confirmed that the fullerene reacted with the photoelectric conversion layer. In addition, Fig. 15 shows the change in the absorption spectrum before and after annealing of the photoelectric conversion layer. In Experimental Example 1, it was found that there was no change in the absorption due to the chromophore before and after annealing, i.e., before and after the reaction of the crosslinking group.

[0190] In contrast, the F used in Experimental Example 2 6 -SubPc-O-Ph-26F 2 As shown in formula (4-1), F has a subphthalocyanine chromophore and a conjugated diene bridging group, but no change was observed in the vibration peaks derived from the bridging group before and after annealing using high-sensitivity infrared spectroscopy. 6 -SubPc-O-Ph-26F 2The bridging group and C 60 It was found that there was no reaction with fullerene. 6 As shown in formula (4-2), -SubPc-F has a subphthalocyanine chromophore but does not have a conjugated diene bridging group, and therefore no change was observed in the vibration peaks derived from the bridging group before and after annealing using high-sensitivity infrared spectroscopy.

[0191] In addition, the chromophore (or dye) and C 60 The presence or absence of reaction products with fullerene can also be confirmed by analyzing the chemical composition in the photoelectric conversion layer using a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (MALDI-TOF-MS).

[0192] The chromophore (or dye) and C used in Experimental Examples 1 to 3 were deposited on a silicon substrate using a vacuum deposition machine. 60 A mixed film with a ratio of 2:1 to fullerene was formed to a thickness of 150 nm to prepare an evaluation sample. In the evaluation sample corresponding to Experimental Example 1, F was removed from the mixed film before annealing. 6 -SubPc-O-2AN and C 60 A chemical composition with a molecular weight of 1:1 addition of fullerene was detected, and no adduct was detected in the mixed film after annealing. Considering this result and the results of the high-sensitivity infrared reflection spectroscopy mentioned above, this is because F 6 -SubPc-O-2AN anthracene moiety and C 60 It is believed that the chemical composition produced by the Diels-Alder reaction with fullerene was formed before annealing, and the crosslinks were removed after annealing. Therefore, it is presumed that the above-mentioned chemical composition was produced by a crosslinking reaction due to radiant heat or substrate heating during film formation by vacuum deposition, and the crosslinks were dissociated by the subsequent annealing.

[0193] In contrast, in the evaluation sample corresponding to Experimental Example 2, no adducts of each chemical species were detected in the mixed film before and after annealing. In addition, in the evaluation sample corresponding to Experimental Example 3, no adducts of each chemical species were detected in the mixed film before and after annealing. From these results, it is clear that F 6 -SubPc-O-Ph-26F 2 and F 6 -SubPc-F, C 60 It is believed that the Diels-Alder reaction with fullerene did not occur.

[0194] Regarding the EQE and open circuit voltage (Voc), in Experimental Example 1, the EQE was 53% and the Voc was 0.652 V. Compared with Experimental Examples 2 and 3, it was found that the EQE was equivalent but the Voc was higher. This is because in Experimental Example 1, F 6 -SubPc-O-2AN is a C-substituted phthalocyanine chromophore via the anthracene substituent at the axial position. 60 By combining with fullerene, the optical absorption wavelength of the subphthalocyanine chromophore does not change, but 60 While giving energy change to fullerene, chromophore and C 60 This is thought to be because the orientation and distance of the fullerene were fixed in a state that was favorable for photoelectric conversion. 60 The LUMO level of fullerene shifts to higher energy, and the chromophore and C 60 The efficiency of electron or energy transfer between fullerenes is improved, and the chromophore and C, which can act as a trap, are also 60 It is believed that the orientation of the fullerene was reduced, resulting in the realization of a photoelectric conversion element with high photoelectric conversion properties.

[0195] (Experiment 2) In Experiment 2, experimental examples 4 and 6 were prepared by mixing a dye and a crosslinking group in the molecule. 60 Photoelectric conversion elements using organic materials with reaction products with fullerenes, and dyes with cross-linking groups in the molecules as experimental examples 5 and 7, and C 60We fabricated a photoelectric conversion device using an organic material that does not produce a reaction product with fullerene, and evaluated its EQE and normalized response speed.

[0196] (Experimental Example 4) A photoelectric conversion element (Experimental Example 4) was fabricated using the same method as in Experimental Example 1, and the photoelectric conversion characteristics were evaluated when a voltage was applied in the reverse direction of the diode.

[0197] (Experimental Example 5) A photoelectric conversion element (Experimental Example 5) was produced by forming the upper electrode using the same method as in Experimental Example 1 and then annealing to dissociate the cross-links. The photoelectric conversion characteristics were evaluated when a voltage was applied in the reverse direction of the diode.

[0198] (Experimental Example 6) F used in Experimental Example 1 6 -SubPc-O-2AN (formula (1-1-16)) instead of F shown in the following formula (1-1-16) 6 A photoelectric conversion element (Example 6) was fabricated using -SubPc-O-β-BT, and a cross-link was generated by annealing after forming the upper electrode, and the photoelectric conversion characteristics were evaluated when a voltage was applied in the reverse direction of the diode. 6 When -SubPc-O-β-BT was used, the results of the IRRAS and MALDI-TOF-MS analyses confirmed that no crosslinking reaction occurred before the annealing treatment, but that a crosslinking reaction occurred after the annealing treatment.

[0199] (Experimental Example 7) F used in Experimental Example 1 6 -SubPc-O-2AN (formula (1-1-16)) instead of F shown in the following formula (1-1-16) 6 A photoelectric conversion element (Experimental Example 7) was produced using the same method as in Experimental Example 1, except that -SubPc-O-β-BT was used, and the photoelectric conversion characteristics were evaluated when a voltage was applied in the reverse direction of the diode.

[0200] [ka]

[0201] The external quantum efficiency (EQE) and normalized response speed when a voltage was applied were evaluated using the following method in Experimental Examples 4 to 7. The results are summarized in Table 2 together with the chromophore (dye) used in each Experimental Example.

[0202] The wavelength of light irradiated from a green LED light source through a bandpass filter onto the photoelectric conversion element is 560 nm, and the light intensity is 162 μW / cm 2 The bias voltage applied between the electrodes of the photoelectric conversion element was controlled using a semiconductor parameter analyzer, and a voltage of 2.6 V was applied to the lower electrode on the negative bias side relative to the upper electrode, and the light current and dark current values ​​were measured to calculate the EQE. In addition, light was irradiated with 2.6 V applied, and the steady-state current was observed. After the light irradiation was immediately stopped, the rate at which the current decayed was quantified by the amount of charge that flowed at that time, and used as an index of response. In this experiment, the comparison was made using the normalized response speed, with the response speed of Experimental Example 4 set to 1.60.

[0203] [Table 2]

[0204] The photoelectric conversion element of Experimental Example 4 exhibited a higher EQE and a faster normalized response speed than the photoelectric conversion element of Experimental Example 5 when a voltage of 2.6 V was applied. This is because in Experimental Example 4, F 6 -SubPc-O-2AN is a C-substituted phthalocyanine chromophore via the anthracene substituent at the axial position. 60 By combining with fullerene, the optical absorption wavelength of the subphthalocyanine chromophore does not change, but 60 While giving energy change to fullerene, chromophore and C 60 This is thought to be because the orientation and distance of the fullerene were fixed in a state that was favorable for photoelectric conversion. 60 The LUMO level of fullerene shifts to higher energy, and the chromophore and C 60The efficiency of electron or energy transfer between fullerenes is improved, and the chromophore and C, which can act as a trap, are also 60 It is believed that the orientation of the fullerene was reduced, resulting in the realization of a photoelectric conversion element with high photoelectric conversion properties and high response speed.

[0205] The photoelectric conversion element of Experimental Example 6 exhibited an EQE and a high normalized response speed equivalent to those of the photoelectric conversion element of Experimental Example 7 when a voltage of 2.6 V was applied. This is because, in Experimental Example 6, 6 -SubPc-O-β-BT is a phthalocyanine chromophore with a benzothiophene substituent at the axial position. 60 By combining with fullerene, the optical absorption wavelength of the subphthalocyanine chromophore does not change, but 60 While giving energy change to fullerene, chromophore and C 60 This is thought to be because the orientation and distance of the fullerene were fixed in a state that was favorable for photoelectric conversion. 60 The LUMO level of fullerene shifts to higher energy, and the chromophore and C 60 The efficiency of electron or energy transfer between fullerenes is improved, and the chromophore and C, which can act as a trap, are also 60 It is believed that the orientation of the fullerene was reduced, resulting in the realization of a photoelectric conversion element with high photoelectric conversion properties and high response speed.

[0206] Although the above describes the embodiments and examples, the present disclosure is not limited to the above embodiments and can be modified in various ways. For example, in the above embodiment, the photoelectric conversion element is configured by stacking an organic photoelectric conversion unit 11G that detects green light, and an inorganic photoelectric conversion unit 11B and an inorganic photoelectric conversion unit 11R that detect blue light and red light, respectively, but the present disclosure is not limited to such a structure. That is, the organic photoelectric conversion unit may detect red light or blue light, or the inorganic photoelectric conversion unit may detect green light.

[0207] The number and ratio of these organic photoelectric conversion units and inorganic photoelectric conversion units are not limited, and two or more organic photoelectric conversion units may be provided, or color signals of multiple colors may be obtained by the organic photoelectric conversion units alone. Furthermore, the organic photoelectric conversion units and inorganic photoelectric conversion units are not limited to a structure in which they are stacked vertically, and may be arranged in parallel along the substrate surface.

[0208] Furthermore, although the above-mentioned embodiment and the like have exemplified the configuration of a back-illuminated solid-state imaging device, the present disclosure is also applicable to a front-illuminated solid-state imaging device. Furthermore, the photoelectric conversion element of the present disclosure does not need to include all of the components described in the above-mentioned embodiment, and conversely, may include other layers.

[0209] Furthermore, in the above-described embodiment and the like, an example has been given in which the photoelectric conversion element 10 is used as the imaging element constituting the imaging device 1, but the photoelectric conversion element 10 of the present disclosure may also be applied to a solar cell.

[0210] 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.

[0211] The present disclosure may be configured as follows. (1) Forming a first electrode; forming a photoelectric conversion layer including a chromophore and a fullerene or a fullerene derivative on the first electrode by using a vacuum deposition method; forming a second electrode on the photoelectric conversion layer; The chromophore and the fullerene or fullerene derivative are bonded via a crosslinking group by heat or light irradiation during the vacuum deposition method or by heating or light irradiation after the formation of the photoelectric conversion layer. A method for manufacturing a photoelectric conversion element. (2) The method for producing a photoelectric conversion element according to (1) above, further comprising adding a hole transporting material to form the photoelectric conversion layer. (3) The method for producing a photoelectric conversion element according to (1) or (2), wherein the chromophore is an organic molecule having absorption in the visible light region and has the crosslinking group. (4) The method for producing a photoelectric conversion element according to any one of (1) to (3), wherein the change in absorption peak wavelength of the chromophore before and after bonding with the fullerene or fullerene derivative via the crosslinking group is within ±10 nm. (5) The method for producing a photoelectric conversion element according to any one of (1) to (4), wherein the crosslinking group is a conjugated diene. (6) The method for producing a photoelectric conversion element according to any one of (1) to (5), wherein one or more molecules of the chromophore are bonded to one molecule of the fullerene or fullerene derivative via the crosslinking group. (7) The fullerene or fullerene derivative is 60 Fullerene or C 70 The method for producing a photoelectric conversion element according to any one of (1) to (6), wherein the photoelectric conversion element is a fullerene. (8) The method for producing a photoelectric conversion element according to (6) or (7), wherein the chromophore is subphthalocyanine, porphyrin, phthalocyanine, dipyrromethane, azadipyrromethane, dipyridyl, azadipyridyl, coumarin, perylene, perylene diimide, pyrene, naphthalene diimide, quinacridone, xanthene, xanthenoxanthene, phenoxazine, indigo, azo, oxazine, benzodithiophene, naphthodithiophene, anthradithiophene, rubicene, anthracene, tetracene, pentacene, anthraquinone, tetraquinone, pentaquinone, dinaphthothienothiophene, diketopyrrolopyrrole, oligothiophene, cyanine, squalium, croconium, or a derivative thereof. (9) The method for producing a photoelectric conversion element according to any one of (1) to (8), wherein the bridging group is any one of benzene, naphthalene, anthracene, tetracene, pentacene, cyclopentadiene, indene, furan, thiophene, benzofuran, benzothiophene, and 1,3-butadiene. (10) The method for producing a photoelectric conversion element according to any one of (2) to (9), wherein the hole transporting material has a HOMO (Highest Occupied Molecular Orbital) level higher than that of the fullerene or fullerene derivative. [Explanation of symbols]

[0212] 1...imaging device, 2...electronic device (camera), 10...photoelectric conversion element, 11...semiconductor substrate, 11G...organic photoelectric conversion section, 11R, 11B...inorganic photoelectric conversion section, 12, 14...interlayer insulating layer, 12A...fixed charge layer, 12B...dielectric layer, 13A, 13C...pad section, 13B...upper contact, 15...lower electrode, 16...photoelectric conversion layer, 17...upper electrode, 18...protective layer, 19...on-chip lens layer, 19L...on-chip lens.

Claims

1. Forming a first electrode; forming a photoelectric conversion layer including a chromophore and a fullerene or a fullerene derivative on the first electrode by using a vacuum deposition method; forming a second electrode on the photoelectric conversion layer; The chromophore, subphthalocyanine, porphyrin, phthalocyanine or a derivative thereof is bonded to the fullerene or fullerene derivative via a crosslinking group by heat or light irradiation during the vacuum deposition method or by heating or light irradiation after the formation of the photoelectric conversion layer. A method for manufacturing a photoelectric conversion element.

2. The method for producing a photoelectric conversion element according to claim 1 , further comprising the step of adding a hole transporting material to form the photoelectric conversion layer.

3. The method for producing a photoelectric conversion element according to claim 1 , wherein the chromophore is an organic molecule having absorption in the visible light region and has the crosslinking group.

4. 2 . The method for producing a photoelectric conversion element according to claim 1 , wherein the change in absorption peak wavelength of the chromophore before and after bonding with the fullerene or fullerene derivative via the crosslinking group is within ±10 nm.

5. The method for producing a photoelectric conversion element according to claim 1 , wherein the crosslinking group is a conjugated diene.

6. The method for producing a photoelectric conversion element according to claim 1 , wherein one or more molecules of the chromophore are bonded to one molecule of the fullerene or fullerene derivative via the crosslinking group.

7. The fullerene or fullerene derivative is ６０ Fullerene or C ７０ The method for producing a photoelectric conversion element according to claim 1 , wherein the photoelectric conversion element is a fullerene.

8. 2. The method for producing a photoelectric conversion element according to claim 1, wherein the subphthalocyanine derivative of the chromophore is F 6 -SubPc.

9. 2. The method for producing a photoelectric conversion element according to claim 1, wherein the crosslinking group is any one of benzene, naphthalene, anthracene, tetracene, pentacene, cyclopentadiene, indene, furan, thiophene, benzofuran, benzothiophene, and 1,3-butadiene.

10. The method for producing a photoelectric conversion element according to claim 2 , wherein the hole transporting material has a HOMO (Highest Occupied Molecular Orbital) level higher than that of the fullerene or fullerene derivative.

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