Photoelectric conversion element and solid-state imaging device

Abstract

To provide a photoelectric conversion element and a solid state image pickup device, capable of improving external quantum efficiency and a response speed.SOLUTION: A photoelectric conversion element according to an embodiment of a present disclosure comprises: a first electrode; a second electrode oppositely arranged to the first electrode; and an organic photoelectric conversion layer that is provided between the first electrode and the second electrode and includes a domain of first organic semiconductor material in a layer. The domain of first organic semiconductor material includes a percolation structure longitudinally crossing the organic photoelectric conversion layer in a film thickness direction, and the domain length of the organic photoelectric conversion layer in a plane direction is smaller than that of the organic photoelectric conversion layer in the film thickness direction. The domain contains a plurality of first organic semiconductor materials. The plurality of first organic semiconductor materials in the domain is laminated in a direction different from a molecular length direction of each first organic semiconductor material in a direction which is larger than 45° and smaller than 90° formed with at least one electrode surface of the first electrode and the second electrode.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a photoelectric conversion element using an organic semiconductor material and a solid-state imaging device including the same. [Background technology]

[0002] In recent years, devices using organic thin films have been developed, and organic photoelectric conversion elements are one of them, and organic thin film solar cells and organic imaging elements using organic photoelectric conversion elements have been proposed. In organic photoelectric conversion elements, a bulk heterostructure in which p-type organic semiconductors and n-type organic semiconductors are mixed is adopted, and external quantum efficiency is improved. However, organic photoelectric conversion elements have the problem that sufficient external quantum efficiency cannot be obtained due to the low conductivity of organic semiconductors. In addition, organic imaging elements have the problem that the electrical output signal is easily delayed with respect to incident light.

[0003] In general, it is known that the orientation of molecules is important for the conduction of organic semiconductors. The same is true for organic photoelectric conversion elements having a bulk heterostructure. For this reason, in an organic photoelectric conversion element in which the conduction direction is perpendicular to the substrate, it is preferable that the organic semiconductor is aligned horizontally to the substrate. In contrast, for example, Patent Document 1 discloses a photoelectric conversion element using an organic semiconductor compound having horizontal alignment. For example, Patent Document 2 discloses an organic thin-film solar cell in which an alignment control layer is provided under the i-layer. For example, Patent Document 3 discloses a method for manufacturing an organic photoelectric conversion element in which the orientation of the photoelectric conversion layer is controlled by controlling the substrate temperature during film formation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-60053 A [Patent Document 2] JP 2007-59457 A [Patent Document 3] JP 2008-258421 A Summary of the Invention [Problem to be solved by the invention]

[0005] Thus, in photoelectric conversion elements using organic semiconductor materials, improvements in external quantum efficiency and response speed are required.

[0006] It is desirable to provide a photoelectric conversion element and a solid-state imaging device that can improve the external quantum efficiency and the response speed. [Means for solving the problem]

[0007] A photoelectric conversion element according to an embodiment of the present disclosure includes a first electrode, a second electrode disposed opposite to the first electrode, and a gate electrode provided between the first electrode and the second electrode, a first organic semiconductor material that is a light absorber, a second organic semiconductor material that is an n-type semiconductor, and a third organic semiconductor material that is a p-type semiconductor; In the layer The third organic semiconductor material has a domain in which the third organic semiconductor material is continuously arranged. An organic photoelectric conversion layer; The third organic semiconductor material the domain has a percolation structure that crosses the organic photoelectric conversion layer in the film thickness direction, and the domain length in the planar direction of the organic photoelectric conversion layer is smaller than the domain length in the film thickness direction of the organic photoelectric conversion layer; The organic photoelectric conversion layer has interference fringes consisting of 2 to 10 lines in a region corresponding to one domain of the third organic semiconductor material observed in a cross-sectional photograph in the thickness direction taken with a transmission electron microscope under a defocus condition shifted by about 1500 nm from a just-focus position to the underfocus side, and the angle between the interference fringes and the electrode surface of the first electrode is greater than 45° and less than 90°. .

[0008] In the solid-state imaging device according to an embodiment of the present disclosure, each pixel includes one or more organic photoelectric conversion units, and the organic photoelectric conversion unit has the photoelectric conversion element according to the embodiment of the present disclosure.

[0009] In the photoelectric conversion element according to the embodiment of the present disclosure and the solid-state imaging device according to the embodiment, an organic photoelectric conversion layer provided between a first electrode and a second electrode is formed with a domain having a predetermined shape in the layer. , and the third organic semiconductor material, which is a p-type semiconductor. This is how it is constructed. The third organic semiconductor material The domain has a percolation structure that crosses the organic photoelectric conversion layer in the thickness direction, and the domain length in the planar direction of the organic photoelectric conversion layer is smaller than the domain length in the thickness direction. Furthermore, the organic photoelectric conversion layer has interference fringes consisting of 2 to 10 lines in a region corresponding to one domain of the third organic semiconductor material observed in a cross-sectional photograph in the thickness direction taken by a transmission electron microscope under a defocus condition shifted about 1500 nm from a just-focus position to the underfocus side, and the angle between the interference fringes and the electrode surface of the first electrode is greater than 45° and less than 90°. This makes it possible to appropriately control the mixed state of the organic semiconductor material that constitutes the organic photoelectric conversion layer.

[0010] According to the photoelectric conversion element of the embodiment of the present disclosure and the solid-state imaging device of the embodiment, the above-described domains are formed in the layer. , and the third organic semiconductor material, which is a p-type semiconductor. Since the organic semiconductor material constituting the organic photoelectric conversion layer is controlled to be in an appropriate mixed state, it is possible to improve the external quantum efficiency and the response speed.

[0011] 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]

[0012] [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 a mixed state of each organic semiconductor material in the organic photoelectric conversion layer shown in FIG. [Diagram 3] This is a TEM image to explain interference fringes. [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] 10 is a schematic cross-sectional view illustrating a configuration of a photoelectric conversion element according to a modified example of the present disclosure. [Figure 8] 2 is a block diagram showing an overall configuration of a solid-state imaging device including the photoelectric conversion element shown in FIG. 1. [Figure 9] 9 is a functional block diagram illustrating an example of a solid-state imaging device (camera) using the solid-state imaging element illustrated in FIG. 8. [Figure 10] 1 is a block diagram showing an example of a schematic configuration of an in-vivo information acquiring system. [Figure 11] 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 12]12 is a block diagram showing an example of a functional configuration of a camera head and a CCU shown in FIG. 11. [Figure 13] 1 is a block diagram showing a schematic configuration example of a vehicle control system; [Figure 14] FIG. 4 is an explanatory diagram showing an example of an installation position of an imaging unit. [Figure 15] FIG. 1 shows a TEM image (A) and its signal intensity (B) of Experimental Example 1. [Figure 16] TEM images of Experimental Examples 1 and 4. [Figure 17] TEM images of Experimental Examples 6 and 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 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 (Photoelectric conversion element having an organic photoelectric conversion layer formed using an organic semiconductor material that forms a domain of a predetermined shape) 1-1. Photoelectric conversion element configuration 1-2. Manufacturing method of photoelectric conversion element 1-3. Actions and Effects 2. Modification (Photoelectric conversion element having multiple organic photoelectric conversion units stacked) 3. Application Examples 4. Working Example

[0014] <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 constitutes one pixel (unit pixel P) in a solid-state imaging device (solid-state 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. 8). The photoelectric conversion element 10 is a so-called vertical spectroscopic type in which one organic photoelectric conversion unit 11G, which selectively detects light in different wavelength ranges and performs photoelectric conversion, and two inorganic photoelectric conversion units 11B and 11R are stacked in the vertical direction. In this embodiment, the organic photoelectric conversion layer 16 constituting the organic photoelectric conversion unit 11G has a configuration formed using an organic semiconductor material (one organic semiconductor material) that forms a domain of a predetermined shape in the layer.

[0015] (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 an organic 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.

[0016] 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.

[0017] In this embodiment, the case where the electrons of pairs of electrons and holes generated by photoelectric conversion are read out as signal charges (where the n-type semiconductor region is the photoelectric conversion layer) will be described. In addition, in the figure, the "+ (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 "+".

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] The vertical transistor Tr1 is a transfer transistor that transfers signal charges (electrons in this case) corresponding to blue, which 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.

[0025] The transfer transistor Tr2 transfers the signal charge (here, electrons) corresponding to red that is generated and accumulated in the inorganic photoelectric conversion section 11R to the floating diffusion FD2, and is configured by, for example, a MOS transistor.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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, an organic photoelectric conversion layer 16, and an upper electrode 17 are laminated in this order from the first surface 11S1 side of the semiconductor substrate 11. The lower electrode 15 is formed separately for each photoelectric conversion element 10, for example. The organic photoelectric conversion layer 16 and the upper electrode 17 are provided as a continuous layer common to the multiple photoelectric conversion elements 10. 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] In the photoelectric conversion element 10 of the present embodiment, light incident on the organic photoelectric conversion section 11G from the upper electrode 17 side is absorbed by the organic photoelectric conversion layer 16. The excitons generated by this move to the interface between the electron donor and electron acceptor constituting the organic 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 upper electrode 17) and the cathode (here, the lower electrode 15), 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.

[0036] The structure and materials of each part will be described below.

[0037] The organic photoelectric conversion unit 11G is an organic photoelectric conversion element that absorbs green light corresponding to a part or the entire wavelength band of a selective wavelength band (for example, 450 nm or more and 650 nm or less) and generates electron-hole pairs.

[0038] 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 these light receiving surfaces. The lower electrode 15 is made of a conductive film having optical transparency, for example, made of ITO (indium tin oxide). However, as a constituent material of the lower electrode 15, in addition to ITO, a tin oxide (SnO2)-based material with a dopant added thereto, or a zinc oxide-based material made of zinc oxide (ZnO) with a dopant added thereto may be used. Examples of the zinc oxide-based material include 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, InSbO4, ZnMgO, CuInO2, MgIN2O4, CdO, ZnSnO3, etc. may also be used.

[0039] The organic photoelectric conversion layer 16 converts light energy into electrical energy. The organic photoelectric conversion layer 16 is composed of, for example, two or more kinds of organic semiconductor materials, and is preferably composed of, for example, either one or both of a p-type semiconductor and an n-type semiconductor. For example, when the organic photoelectric conversion layer 16 is composed of two kinds of organic semiconductor materials, a p-type semiconductor and an n-type semiconductor, it is preferable that one of the p-type semiconductor and the n-type semiconductor is a material that is transparent to visible light, and the other is a material that photoelectrically converts light in a selective wavelength range (for example, 450 nm or more and 650 nm or less). Alternatively, the organic photoelectric conversion layer 16 is preferably composed of three kinds of organic semiconductor materials, a material (light absorber) that photoelectrically converts light in a selective wavelength range, and an n-type semiconductor and a p-type semiconductor that are transparent to visible light. The organic photoelectric conversion layer 16 has a bulk heterostructure in which these multiple types of organic semiconductor materials are randomly mixed in the layer.

[0040] FIG. 2 is a schematic diagram showing an example of a mixed state of each organic semiconductor material in the organic photoelectric conversion layer 16 of the present embodiment. As shown in FIG. 2, for example, the above three types of organic semiconductor materials (light absorber, p-type semiconductor, and n-type semiconductor) are randomly mixed in the organic photoelectric conversion layer 16. In the organic photoelectric conversion layer 16, each of them forms a grain (for example, grain Gc of the light absorber and grain Gn of the n-type semiconductor). In this embodiment, the layer has a domain (for example, domain Dp) of at least one organic semiconductor material (for example, p-type semiconductor (one organic semiconductor material)) among the multiple types of organic semiconductor materials. Note that the domain is, for example, a region in which one organic semiconductor material is continuously arranged. In addition, a domain other than a p-type semiconductor (for example, an n-type semiconductor or a light absorber) may be formed in the organic photoelectric conversion layer 16. In addition, the domain may be configured to include two or more organic semiconductor materials.

[0041] The domains Dp of the p-type semiconductor in this embodiment preferably have a percolation structure that crosses the organic photoelectric conversion layer 16 in the film thickness direction (Y-axis direction). Furthermore, the domains Dp of the p-type semiconductor preferably have a shape in which the length (domain length) of the domain in the planar direction (e.g., X-axis direction) is smaller than the domain length in the film thickness direction. That is, the p-type semiconductor preferably forms domains Dp that extend in the p-film thickness direction of the organic photoelectric conversion layer 16.

[0042] 3 is a partially enlarged image (TEM image) of an organic photoelectric conversion layer 16 (Experimental Example 1 described later) produced using a p-type semiconductor that forms the above-mentioned domains, taken under defocused conditions by a transmission electron microscope. In the organic photoelectric conversion layer 16 of the present embodiment, interference fringes consisting of two or more lines as shown by the dotted lines in FIG. 3 are observed in the region corresponding to the domain Dp. The number of lines that make up the interference fringes is preferably less than 10.

[0043] The interference fringes are observed due to the phase contrast caused by the period in the long axis direction of the p-type semiconductor molecules forming the domain and the wave nature of electrons. That is, of the two or more lines constituting the interference fringes, each pair of adjacent lines corresponds to the molecular period in the long axis direction of the p-type semiconductor molecules. The interference fringes extend in the organic photoelectric conversion layer 16 in the approximate film thickness direction, and the length is preferably 20 nm or more. In addition, the extension direction of the interference fringes is preferably such that the angle between the interference fringes and the electrode surface of the lower electrode 15 is greater than 45° and less than 90°. The distance between the two lines is preferably within ±50% of the molecular length of the p-type semiconductor, and more preferably within ±30%. That is, between the two lines constituting the interference fringes, p-type semiconductors are periodically stacked in the same direction. The molecular length of the p-type semiconductor is the molecular length in the long axis direction of the p-type semiconductor.

[0044] As described above, the organic photoelectric conversion layer 16 is preferably composed of two types of organic semiconductor materials, an n-type semiconductor and a p-type semiconductor, or three types of organic semiconductor materials, an optical absorber, an n-type semiconductor, and a p-type semiconductor, and has a junction surface (p / n junction surface) between the p-type semiconductor and the n-type semiconductor in the layer. The optical absorber has a maximum absorption wavelength in the range of, for example, 450 nm to 650 nm. The p-type semiconductor functions relatively as an electron donor (donor), and it is preferable to use, for example, a material having hole transport properties. The n-type semiconductor functions relatively as an electron acceptor (acceptor), and it is preferable to use, for example, a material having electron transport properties. The organic photoelectric conversion layer 16 provides a place where excitons generated when light is absorbed are separated into electrons and holes, and specifically, the excitons are separated into electrons and holes at the interface (p / n junction surface) between the electron donor and the electron acceptor. The thickness of the organic photoelectric conversion layer 16 is, for example, 50 nm to 500 nm. The surface roughness of the interface between the organic photoelectric conversion layer 16 and the upper electrode 17 is preferably 10 nm or less.

[0045] In this embodiment, an example in which a p-type semiconductor forms the domain Dp has been described, but the present invention is not limited to this. For example, an n-type semiconductor may form the domain.

[0046] The upper electrode 17 is made of a conductive film having the same optical transparency as the lower electrode 15. In a solid-state imaging device 1 using the photoelectric conversion element 10 as one pixel, the upper electrode 17 may be separated for each pixel, or may be formed as an electrode common to each pixel. The thickness of the upper electrode 17 is, for example, 10 nm to 200 nm.

[0047] Other layers may be provided between the organic photoelectric conversion layer 16 and the lower electrode 15, and between the organic photoelectric conversion layer 16 and the upper electrode 17. Specifically, for example, an undercoat film, a hole transport layer, an electron blocking film, the organic photoelectric conversion layer 16, a hole blocking film, a buffer film, an electron transport layer, and a work function adjusting film may be laminated in this order from the lower electrode 15 side.

[0048] 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 the film having a negative fixed charge include hafnium oxide, aluminum oxide, zirconium oxide, tantalum oxide, and titanium oxide. In 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, rhodium oxide, thulium oxide, ytterbium oxide, lutetium oxide, yttrium oxide, aluminum nitride film, hafnium oxynitride film, and aluminum oxynitride film.

[0049] 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.

[0050] 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.

[0051] The interlayer insulating layer 14 is, for example, a single layer film made of one of silicon oxide, silicon nitride, silicon oxynitride (SiON), etc., or a laminated film made of two or more of these materials.

[0052] 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.

[0053] 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.

[0054] Fig. 4 is a plan view showing an example of the configuration of a photoelectric conversion element having pixels 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. 8.

[0055] 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. 3), 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 solid-state 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.

[0056] 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 (MOSFET) 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 .

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The technology according to the present disclosure can be applied to the above-described photoelectric conversion element.

[0061] (1-2. Method for manufacturing photoelectric conversion element) The photoelectric conversion element 10 of the present embodiment can be manufactured, for example, as follows.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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).

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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).

[0070] Next, the lower electrode 15, the organic 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 organic photoelectric conversion layer 16 is formed by, for example, forming a film of the above three types of organic semiconductor materials using, for example, a vacuum deposition method. Finally, an on-chip lens layer 19 having a plurality of on-chip lenses 19L on its surface is disposed. Through the above steps, the photoelectric conversion element 10 shown in FIG. 1 is completed.

[0071] As described above, when another organic layer (e.g., an electron blocking layer, etc.) is formed on or under the organic photoelectric conversion layer 16, it is desirable to form it continuously in a vacuum process (in a vacuum integrated process). In addition, the method of forming the organic 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.

[0072] 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.

[0073] (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.

[0074] 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 electrons 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.

[0075] 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.

[0076] 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.

[0077] 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 organic 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.

[0078] (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.

[0079] (1-3. Actions and Effects) As mentioned above, a bulk heterostructure in which p-type organic semiconductors and n-type organic semiconductors are mixed is used in organic photoelectric conversion elements used in organic thin-film solar cells, organic imaging elements, etc. However, since organic semiconductors have low conductivity, there is a problem that sufficient quantum efficiency cannot be obtained in organic photoelectric conversion elements, and the electrical output signal is easily delayed with respect to the incident light.

[0080] In general, it is known that molecular orientation is important for the conduction of organic semiconductors, and this is also true for organic photoelectric conversion elements having a bulk heterostructure. In organic photoelectric conversion elements in which the conduction direction is perpendicular to the substrate, it is generally known that the organic semiconductor is preferably aligned horizontally to the substrate. For this reason, as described above, various efforts have been made to improve the horizontal alignment of the organic semiconductor that constitutes the organic photoelectric conversion layer.

[0081] However, simply aligning organic molecules horizontally to the substrate may not improve the conduction characteristics of the organic photoelectric conversion element sufficiently, and quantum efficiency and response may not be improved sufficiently. In a photoelectric conversion element having a bulk heterostructure, it is required that the materials constituting the bulk heterostructure in the layer form appropriate grains. For example, if there is a large defect at the grain boundary, the conduction characteristics will be significantly reduced. This is because when charges are conducted through the grain boundary, the charges are captured in the trap level of the defect, or the defects become an energy barrier and inhibit the charge transfer between grains. This is thought to lead to a deterioration in quantum efficiency and response speed.

[0082] In contrast, in the present embodiment, the organic photoelectric conversion layer 16 is configured using an organic semiconductor material (one organic semiconductor material) that forms a domain (for example, domain Dp) of a predetermined shape within the layer. Specifically, the organic photoelectric conversion layer 16 is formed to have a percolation structure that runs vertically through the organic photoelectric conversion layer 16 in the film thickness direction, and includes an organic semiconductor material that forms a domain having a shape in which the length of the domain in the planar direction is smaller than the length of the domain in the film thickness direction. This makes it possible to appropriately control the mixed state of the organic semiconductor material in the organic photoelectric conversion layer.

[0083] As described above, in the photoelectric conversion element 10 of the present embodiment, the organic photoelectric conversion layer 16 is configured using one organic semiconductor material (e.g., a p-type semiconductor) that forms the above-mentioned domains in the organic photoelectric conversion layer 16. This allows the organic semiconductor material (e.g., in addition to the above-mentioned p-type semiconductor, an n-type semiconductor and a light absorber) that configures the organic photoelectric conversion layer 16 to be controlled to an appropriate mixed state. This makes it possible to improve the external quantum efficiency and response speed.

[0084] Next, modified examples of the present disclosure will be described. Note that components corresponding to the photoelectric conversion element 10 of the above embodiment are given the same reference numerals and the description thereof will be omitted.

[0085] <2. Modifications> 7 shows a cross-sectional configuration of a photoelectric conversion element (photoelectric conversion element 20) according to a modified example of the present disclosure. Like the photoelectric conversion element 10 of the above-described embodiment, the photoelectric conversion element 20 constitutes one unit pixel P in a solid-state imaging element (solid-state imaging device 1) such as a back-illuminated CCD image sensor or CMOS image sensor. The photoelectric conversion element 20 of this modified example has a configuration in which a red photoelectric conversion unit 40R, a green photoelectric conversion unit 40G, and a blue photoelectric conversion unit 40B are stacked in this order on a silicon substrate 81 via an insulating layer 82.

[0086] The red photoelectric conversion unit 40R, the green photoelectric conversion unit 40G, and the blue photoelectric conversion unit 40B each have an organic photoelectric conversion layer 42R, 42G, or 42B between a pair of electrodes, specifically, between the first electrode 41R and the second electrode 43R, between the first electrode 41G and the second electrode 43G, and between the first electrode 41B and the second electrode 43B, respectively. The organic photoelectric conversion layers 42R, 42G, or 42B each contain a ChDT derivative, thereby achieving the same effects as those of the above embodiment.

[0087] As described above, the photoelectric conversion element 20 has a configuration in which the red photoelectric conversion unit 40R, the green photoelectric conversion unit 40G, and the blue photoelectric conversion unit 40B are stacked in this order on the silicon substrate 81 via the insulating layer 82. On the blue photoelectric conversion unit 40B, the on-chip lens 19L is provided via the protective layer 18 and the on-chip lens layer 19. In the silicon substrate 81, the red storage layer 210R, the green storage layer 210G, and the blue storage layer 210B are provided. The light incident on the on-chip lens 19L is photoelectrically converted by the red photoelectric conversion unit 40R, the green photoelectric conversion unit 40G, and the blue photoelectric conversion unit 40B, and the signal charges are sent from the red photoelectric conversion unit 40R to the red storage layer 210R, from the green photoelectric conversion unit 40G to the green storage layer 210G, and from the blue photoelectric conversion unit 40B to the blue storage layer 210B, respectively. The signal charges may be either electrons or holes generated by photoelectric conversion, but the following description will be given taking as an example a case where electrons are read out as the signal charges.

[0088] The silicon substrate 81 is, for example, a p-type silicon substrate. The red storage layer 210R, the green storage layer 210G, and the blue storage layer 210B provided on the silicon substrate 81 each include an n-type semiconductor region, and the signal charges (electrons) supplied from the red photoelectric conversion unit 40R, the green photoelectric conversion unit 40G, and the blue photoelectric conversion unit 40B are stored in the n-type semiconductor region. The n-type semiconductor regions of the red storage layer 210R, the green storage layer 210G, and the blue storage layer 210B are formed, for example, by doping the silicon substrate 81 with an n-type impurity such as phosphorus (P) or arsenic (As). The silicon substrate 81 may be provided on a support substrate (not shown) made of glass or the like.

[0089] Silicon substrate 81 is provided with pixel transistors for reading out electrons from red storage layer 210R, green storage layer 210G, and blue storage layer 210B, and transferring them to, for example, vertical signal lines (vertical signal lines Lsig in FIG. 8 described below). Floating diffusions of these pixel transistors are provided in silicon substrate 81, and these floating diffusions are connected to red storage layer 210R, green storage layer 210G, and blue storage layer 210B. The floating diffusions are formed of n-type semiconductor regions.

[0090] The insulating layer 82 is made of, for example, silicon oxide, silicon nitride, silicon oxynitride, hafnium oxide, or the like. The insulating layer 82 may be made of a plurality of types of insulating films stacked one on another. The insulating layer 82 may be made of an organic insulating material. The insulating layer 82 is provided with plugs and electrodes for connecting the red storage layer 210R and the red photoelectric conversion unit 40R, the green storage layer 210G and the green photoelectric conversion unit 40G, and the blue storage layer 210B and the blue photoelectric conversion unit 40B, respectively.

[0091] The red photoelectric conversion unit 40R has a first electrode 41R, an organic photoelectric conversion layer 42R, and a second electrode 43R in this order from the position closest to the silicon substrate 81. The green photoelectric conversion unit 40G has a first electrode 41G, an organic photoelectric conversion layer 42G, and a second electrode 43G in this order from the position closest to the red photoelectric conversion unit 40R. The blue photoelectric conversion unit 40B has a first electrode 41B, an organic photoelectric conversion layer 42B, and a second electrode 43B in this order from the position closest to the green photoelectric conversion unit 40G. An insulating layer 44 is provided between the red photoelectric conversion unit 40R and the green photoelectric conversion unit 40G, and an insulating layer 45 is provided between the green photoelectric conversion unit 40G and the blue photoelectric conversion unit 40B. The red photoelectric conversion section 40R selectively absorbs red light (e.g., wavelength of 600 nm or more and less than 700 nm), the green photoelectric conversion section 40G selectively absorbs green light (e.g., wavelength of 480 nm or more and less than 600 nm), and the blue photoelectric conversion section 40B selectively absorbs blue light (e.g., wavelength of 400 nm or more and less than 480 nm), generating electron-hole pairs.

[0092] The first electrode 41R extracts the signal charge generated in the organic photoelectric conversion layer 42R, the first electrode 41G extracts the signal charge generated in the organic photoelectric conversion layer 42G, and the first electrode 41B extracts the signal charge generated in the organic photoelectric conversion layer 42B. The first electrodes 41R, 41G, and 41B are provided, for example, for each pixel. The first electrodes 41R, 41G, and 41B are made of, for example, a light-transmitting conductive material, specifically, ITO. The first electrodes 41R, 41G, and 41B may be made of, for example, a tin oxide-based material or a zinc oxide-based material. The tin oxide-based material is tin oxide to which a dopant is added, and the zinc oxide-based material is, for example, aluminum zinc oxide in which aluminum is added as a dopant to zinc oxide, gallium zinc oxide in which gallium is added as a dopant to zinc oxide, and indium zinc oxide in which indium is added as a dopant to zinc oxide. Other than these, it is also possible to use IGZO, CuI, InSbO4, ZnMgO, CuInO2, MgIn2O4, CdO, ZnSnO3, etc. The thickness of the first electrodes 41R, 41G, 41B is, for example, 50 nm to 500 nm.

[0093] For example, an electron transport layer may be provided between the first electrode 41R and the organic photoelectric conversion layer 42R, between the first electrode 41G and the organic photoelectric conversion layer 42G, and between the first electrode 41B and the organic photoelectric conversion layer 42B. The electron transport layer is for accelerating the supply of electrons generated in the organic photoelectric conversion layers 42R, 42G, and 42B to the first electrodes 41R, 41G, and 41B, and is made of, for example, titanium oxide or zinc oxide. The electron transport layer may be formed by laminating titanium oxide and zinc oxide. The thickness of the electron transport layer is, for example, 0.1 nm to 1000 nm, and preferably 0.5 nm to 300 nm.

[0094] The organic photoelectric conversion layers 42R, 42G, and 42B each absorb light in a selective wavelength range and perform photoelectric conversion, and transmit light in other wavelength ranges. Here, the light in the selective wavelength range is, for example, light in a wavelength range of 600 nm or more and less than 700 nm in the organic photoelectric conversion layer 42R, light in a wavelength range of 480 nm or more and less than 600 nm in the organic photoelectric conversion layer 42G, and light in a wavelength range of 400 nm or more and less than 480 nm in the organic photoelectric conversion layer 42B. The thickness of the organic photoelectric conversion layers 42R, 42G, and 42B is, for example, 50 nm or more and 500 nm or less.

[0095] The organic photoelectric conversion layers 42R, 42G, and 42B are preferably configured to include, for example, two or more organic semiconductor materials, and are preferably configured to include, for example, either one or both of a p-type semiconductor and an n-type semiconductor, in the case where the organic photoelectric conversion layers 42R, 42G, and 42B are respectively configured with two types of organic semiconductor materials, a p-type semiconductor and an n-type semiconductor, it is preferable that one of the p-type semiconductor and the n-type semiconductor is a material that is transparent to visible light, and the other is a material that photoelectrically converts light in a selective wavelength range (for example, 450 nm or more and 650 nm or less). Alternatively, it is preferable that the organic photoelectric conversion layers 42R, 42G, and 42B are each configured with three types of organic semiconductor materials, a material (light absorber) that photoelectrically converts light in a selective wavelength range corresponding to each layer, and an n-type semiconductor and a p-type semiconductor that are transparent to visible light.

[0096] Each of the organic photoelectric conversion layers 42R, 42G, and 42B has a bulk heterostructure in which these multiple types of organic semiconductor materials are randomly mixed. In this modification, at least one of the organic photoelectric conversion layers 42R, 42G, and 42B has a configuration in which a domain (e.g., domain Dp) having a configuration similar to that of the organic photoelectric conversion layer 16 in the above embodiment is formed in the layer.

[0097] Between the organic photoelectric conversion layer 42R and the second electrode 43R, between the organic photoelectric conversion layer 42G and the second electrode 43G, and between the organic photoelectric conversion layer 42B and the second electrode 43B, for example, a hole transport layer may be provided. The hole transport layer is for accelerating the supply of holes generated in the organic photoelectric conversion layers 42R, 42G, and 42B to the second electrodes 43R, 43G, and 43B, and is made of, for example, molybdenum oxide, nickel oxide, or vanadium oxide. The hole transport layer may be made of an organic material such as PEDOT (Poly(3,4-ethylenedioxythiophene)) and TPD (N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine). The thickness of the hole transport layer is, for example, 0.5 nm or more and 100 nm or less.

[0098] The second electrode 43R is for extracting holes generated in the organic photoelectric conversion layer 42R, the second electrode 43G is for extracting holes generated in the organic photoelectric conversion layer 42G, and the second electrode 43B is for extracting holes generated in the organic photoelectric conversion layer 42G. The holes extracted from the second electrodes 43R, 43G, and 43B are discharged to, for example, a p-type semiconductor region (not shown) in the silicon substrate 81 via each transmission path (not shown). The second electrodes 43R, 43G, and 43B are made of a conductive material such as gold, silver, copper, and aluminum. As with the first electrodes 41R, 41G, and 41B, the second electrodes 43R, 43G, and 43B may be made of a transparent conductive material. In the photoelectric conversion element 20, the holes extracted from the second electrodes 43R, 43G, and 43B are discharged, so that, for example, when a plurality of photoelectric conversion elements 20 are arranged in a solid-state imaging device 1 described later, the second electrodes 43R, 43G, and 43B may be provided in common to each of the photoelectric conversion elements 20 (unit pixels P). The thickness of the second electrodes 43R, 43G, and 43B is, for example, 0.5 nm or more and 100 nm or less.

[0099] The insulating layer 44 is for insulating the second electrode 43R from the first electrode 41G, and the insulating layer 45 is for insulating the second electrode 43G from the first electrode 41B. The insulating layers 44 and 45 are made of, for example, a metal oxide, a metal sulfide, or an organic material. Examples of metal oxides include silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, zinc oxide, tungsten oxide, magnesium oxide, niobium oxide, tin oxide, and gallium oxide. Examples of metal sulfides include zinc sulfide and magnesium sulfide. The band gap of the material constituting the insulating layers 44 and 45 is preferably 3.0 eV or more. The thickness of the insulating layers 44 and 45 is, for example, 2 nm or more and 100 nm or less.

[0100] As described above, in at least one layer of the organic photoelectric conversion layers 42R, 42G, and 42B, an organic semiconductor material is used that has a percolation structure that runs vertically through the organic photoelectric conversion layer (for example, the organic photoelectric conversion layer 42R) in the film thickness direction, and that forms domains whose length in the planar direction is smaller than that in the film thickness direction. This allows the organic semiconductor material (for example, in addition to the p-type semiconductor, the n-type semiconductor and the light absorber) that constitutes the organic photoelectric conversion layer (for example, the organic photoelectric conversion layer 42R) to be controlled to an appropriate mixed state. This makes it possible to improve the external quantum efficiency and the response speed.

[0101] <3. Application Examples> (Application example 1) 8 shows the overall configuration of a solid-state imaging device 1 in which, for example, the photoelectric conversion element 10 described in the above embodiment is used for each pixel. This solid-state 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 this pixel section 1a, which is composed of, for example, a row scanning section 131, a horizontal selection section 133, a column scanning section 134, and a system control section 132.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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 solid-state 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.

[0107] (Application example 2) The above-mentioned solid-state imaging device 1 can be applied to any type of electronic device (solid-state imaging device) equipped with an imaging function, such as a camera system such as a digital still camera or a video camera, or a mobile phone equipped with an imaging function. As an example, a schematic configuration of a camera 2 is shown in Fig. 9. The camera 2 is, for example, a video camera capable of taking still or moving images, and includes the solid-state imaging device 1, an optical system (optical lens) 310, a shutter device 311, a drive unit 313 for driving the solid-state imaging device 1 and the shutter device 311, and a signal processing unit 312.

[0108] The optical system 310 guides image light (incident light) from a subject to the pixel section 1a of the solid-state imaging device 1. The 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 solid-state imaging device 1. The drive section 313 controls the transfer operation of the solid-state 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 solid-state 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.

[0109] (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.

[0110] FIG. 10 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.

[0111] The in-vivo information acquisition system 10001 includes a capsule endoscope 10100 and an external control device 10200 .

[0112] 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.

[0113] 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.

[0114] 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.

[0115] The configurations and functions of the capsule endoscope 10100 and the external control device 10200 will be described in more detail.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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. 10, 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.

[0123] 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.

[0124] 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.

[0125] 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).

[0126] 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.

[0127] (Application example 4) <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.

[0128] FIG. 11 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.

[0129] 11 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] FIG. 12 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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 .

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] Although an endoscopic surgery system has been described as an example here, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0160] (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.

[0161] FIG. 13 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.

[0162] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 13, 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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. 13, 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.

[0172] FIG. 14 is a diagram showing an example of the installation position of the imaging unit 12031.

[0173] In FIG. 14, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0174] 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.

[0175] 14 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] <4. Examples> Next, an embodiment of the present disclosure will be described in detail.

[0181] (Evaluation of electrical characteristics) First, a Si substrate with a 50 nm thick ITO electrode (lower electrode) was cleaned by UV / ozone treatment, and then 1×10 -5 The organic photoelectric conversion layer was formed at a substrate temperature of 40° C. by a resistance heating method while rotating the substrate holder under a vacuum of 0.1 Pa or less. The materials for the organic photoelectric conversion layer were 3,6BP-BBTN shown in the following formula (1) as a hole transport material (P material), a subphthalocyanine derivative (F6-SubPc-OPh 26 F2) and fullerene C60 were used as an electron transport material (N material), and these were simultaneously evaporated. The evaporation rate ratio was 3,6BP-BBTN:F6-SubPc-OPh 26The ratio of F2:C60 was 4:4:2, and the total thickness was 230 nm. Next, B4PyPMP was deposited as a buffer layer on the photoelectric conversion layer by vacuum deposition at a substrate temperature of 0°C to a thickness of 5 nm. Next, ITO was deposited as an upper electrode 17 by sputtering to a thickness of 100 nm, and then heat treatment was performed at 160°C. As a result, a photoelectric conversion element (Experimental Example 1) having a photoelectric conversion area of ​​1 mm x 1 mm was produced.

[0182] In addition, photoelectric conversion elements were prepared as Experimental Examples 2 to 8. In Experimental Examples 2 and 3, the photoelectric conversion elements were prepared using the same method as in Experimental Example 1, except that the substrate temperature during deposition of the organic photoelectric conversion layer was set to 25°C (Experimental Example 2) and 0°C (Experimental Example 3). In Experimental Example 4, the photoelectric conversion element was prepared using the same method as in Experimental Example 3, except that the heat treatment after deposition of the organic film (after deposition of the buffer layer) was omitted (as depo). In Experimental Example 5, the photoelectric conversion element was prepared using the same method as in Experimental Example 3, except that BP-ChDT (formula (2)) was used as the P material. In Experimental Examples 6, 7, and 8, DBPA (Formula (3)) was used as the P material, and the photoelectric conversion elements were fabricated with the substrate temperature during deposition of the organic photoelectric conversion layer and the heat treatment conditions after deposition of the organic film set to -10°C, ANL 160°C (Experimental Example 6), -10°C, As depo (Experimental Example 7), and 40°C, ANL 160°C (Experimental Example 8), respectively.

[0183] [ka]

[0184] The responsiveness (afterimage characteristics) of Experimental Examples 1 to 8 was evaluated. The afterimage characteristics were evaluated by measuring the speed at which the bright current value observed during light irradiation falls after the light irradiation is stopped using a semiconductor parameter analyzer. Specifically, the amount of light irradiated from the light source to the photoelectric conversion element through the filter was set to 1.62 μW / cm2, and the bias voltage applied between the electrodes was set to -2.6 V. After observing the steady-state current in this state, the light irradiation was stopped and the state in which the current decayed was observed. Next, the area surrounded by the current-time curve and the dark current was set to 100%, and the time until this area corresponded to 3% was used as an index of responsiveness. All of these evaluations were performed at room temperature.

[0185] The quantum efficiency (external quantum efficiency; EQE) of Experimental Examples 1 to 8 was evaluated using a semiconductor parameter analyzer. Specifically, the amount of light (LED light with a wavelength of 560 nm) irradiated from the light source to the photoelectric conversion element through a filter was 1.62 μW / cm 2 The external photoelectric conversion efficiency was calculated from the bright current value and the dark current value when the bias voltage applied between the electrodes was set to −2.6 V.

[0186] (Transmission electron microscope (TEM) analysis) In addition, samples for TEM observation of the cross sections of the organic photoelectric conversion layers corresponding to Experimental Examples 1 to 8 were prepared, and the P material domains in the organic photoelectric conversion layers were observed. The domains of the P material (organic semiconductor material having hole transport properties) were confirmed by observing the transmission images using a transmission electron microscope.

[0187] First, a thin section sample was prepared from the organic photoelectric conversion layer region of the sample of the above-mentioned Experimental Example 1 using a focused ion beam (FIB, HELIOS NANOLAB 400S manufactured by FEI), and then the damaged layer of the FIB processed end surface was removed using an ion milling device (Model 1040 manufactured by Fischione). The TEM (JEM-300F manufactured by JEOL) was used to observe the transmission image at an acceleration voltage of 300 kV and low irradiation of electron beams. The defocus condition for observing the domain was a state in which the transmission image was in focus, that is, the state was shifted about 1500 nm to the under side from the just focus position. In addition, the above-mentioned Experimental Examples 2 to 8 were analyzed using a transmission microscope using the same method.

[0188] [Table 1]

[0189] FIG. 15 shows (A) a TEM image of an enlarged portion of the interference fringes in Experimental Example 1, and (B) the signal intensity of the TEM image measured using TEM imaging software (Digital Micrograph). The interference fringes in the TEM image appear as peaks of signal intensity, either mountains or valleys, depending on the strength of the contrast. As described above, the pair of adjacent lines constituting the interference fringes represents the molecular period in the long axis direction of the P material. The molecular length of the P material used in Experimental Example 1 was about 3 nm, whereas the distance between the pair of lines constituting the interference fringes in FIG. 15(B) was 2.2 nm. From this, it can be said that the interference fringes are interference fringes with a period in the long axis direction of the P material.

[0190] FIG. 16 shows TEM images of Experimental Example 1 (A) and Experimental Example 4 (B). FIG. 17 shows TEM images of Experimental Example 6 (A) and Experimental Example 8 (B). Table 1 summarizes the P materials used in Experimental Examples 1 to 8, the film formation conditions of the organic photoelectric conversion layer, and the electrical characteristics and the results of the transmission microscope analysis. In Experimental Examples 1 and 4 using 3,6BP-BBTN as the P material, interference fringes showing domains extending in the film thickness direction were observed (for example, within the circle in FIG. 16 (A)) in Experimental Example 1, in which heat treatment was performed at 160° C. after the organic film was formed, and interference fringes were not observed in Experimental Example 4, in which heat treatment was not performed after the organic film was formed (as depo). Experimental Example 1 had improved afterimage characteristics compared to Experimental Example 4, and furthermore, the quantum efficiency was improved. This revealed the effectiveness of the domains in the organic photoelectric conversion layer. Moreover, in Experimental Example 3, which used BP-ChDT as the P material and had excellent afterimage characteristics and quantum efficiency, domains extending in the film thickness direction were also confirmed, indicating that the formation of domains extending in the film thickness direction is significant in improving the electrical characteristics.

[0191] On the other hand, in Experimental Example 6, in which DBPA was used as the P material and the organic photoelectric conversion layer was formed at 40°C, domains were observed in the organic photoelectric conversion layer, but both the afterimage characteristics and quantum efficiency were significantly deteriorated. In Experimental Example 8, many (10 or more) interference fringes were confirmed. This shows that if the domains are too large, the electrical characteristics are deteriorated.

[0192] In the above embodiment, it is preferable that the angle between the interference fringes and the electrode surface of the lower electrode 15 is greater than 45° and less than 90°. This is for the following reasons. When a domain is formed in the organic photoelectric conversion layer, this domain becomes a charge transport path. In order to transport holes or electrons more efficiently in the upper and lower electrode directions, it is desirable to form a domain extending in a direction perpendicular to the electrode surface. For example, a domain made of a P material contributes to the transport efficiency of holes, thereby improving the response speed and obtaining good afterimage characteristics. In this embodiment, a relatively good afterimage characteristic was obtained even when the angle between the interference fringes and the electrode surface was 49.7° (Experimental Example 3). From the above, it can be said that the extension direction of the interference fringes is preferable that the angle between the interference fringes and the electrode surface is greater than 45° and less than 90°. More preferably, it is greater than 63° and less than 90°, and furthermore, it is more preferable that it is greater than 82° and less than 90°.

[0193] In the above embodiment, it has been described that the interval between two adjacent lines constituting the interference fringes is preferably within ±50% of the molecular length of the p-type semiconductor, for the following reasons. The molecular length in the long axis direction of 3,6BP-BBTN used in Experimental Example 1 is about 3 nm, while the interval between the interference fringes is 2.2 nm, and the difference is about 27%. A major factor of this difference is that the molecular long axis is not perpendicular to the extension direction of the interference fringes or the electron transmission direction but is inclined. When the molecular long axis is inclined with respect to the electrode surface, the interval between a pair of lines constituting the interference fringes becomes shorter than the molecular length. Furthermore, the following fluctuation factors due to the focus amount of the transmission electron microscope are considered. As a first factor, the image of the transmission electron microscope is blurred differently depending on the defocus amount, and as the defocus amount increases, the interval between a pair of lines constituting the interference fringes becomes longer. As a second factor, the defocus amount fluctuates due to an error in the position of defocus zero. The standard for zero defocus is determined by visually checking the contrast at the edge of the sample while changing the sample height, and judging from the position where the contrast is weakest. The third factor is that the amount of focus differs depending on the position of the p-type semiconductor in the sample, which causes the spacing between the pair of lines to vary. From the above, it can be said that it is preferable for the spacing between the two adjacent lines that make up the interference fringes to be within ±50% of the molecular length of the p-type semiconductor.

[0194] Although the above describes the embodiment, the modified example, and the example, the present disclosure is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, the photoelectric conversion element is configured by stacking the organic photoelectric conversion unit 11G that detects green light, and the inorganic photoelectric conversion unit 11B and the 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.

[0195] 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.

[0196] Furthermore, although the above-mentioned embodiments 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. Also, the photoelectric conversion element of the present disclosure does not need to include all of the components described in the above-mentioned embodiments, and conversely, may include other layers.

[0197] 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.

[0198] The present disclosure may be configured as follows. (1) A first electrode; a second electrode disposed opposite the first electrode; The first electrode and the second electrode are provided between the first electrode and the second electrode, a first organic semiconductor material that is a light absorber, a second organic semiconductor material that is an n-type semiconductor, and a third organic semiconductor material that is a p-type semiconductor; In the layer The third organic semiconductor material has a domain in which the third organic semiconductor material is continuously arranged. An organic photoelectric conversion layer; the third organic semiconductor material the domain has a percolation structure that crosses the organic photoelectric conversion layer in a thickness direction, and the domain length in a planar direction of the organic photoelectric conversion layer is smaller than the domain length in the thickness direction of the organic photoelectric conversion layer, The organic photoelectric conversion layer has interference fringes composed of two or more and less than ten lines in a region corresponding to one domain of the third organic semiconductor material observed in a cross-sectional photograph in a thickness direction taken by a transmission electron microscope under a defocus condition shifted about 1500 nm from a just-focus position to the underfocus side, and an angle between the interference fringes and an electrode surface of the first electrode is greater than 45° and less than 90°. Photoelectric conversion element. (2) before Two or more lines that make up the interference fringes Less than 10 The spacing between the lines is the third organic semiconductor material The photoelectric conversion element according to (1) above, wherein the molecular length is within ±50% of the molecular length. (3) The photoelectric conversion element according to (2) above, wherein the length of the interference fringes is 20 nm or more. (4) The photoelectric conversion element according to (2) or (3), wherein an angle between the interference fringes and an electrode surface of the first electrode is greater than 45° and equal to or smaller than 90°. (5) The surface roughness of the interface between the organic photoelectric conversion layer and the second electrode is 10 nm or less. Any of the above (1) to (4) The photoelectric conversion element according to claim 1. (6) the third organic semiconductor material has hole transport properties , any one of (1) to (5) above The photoelectric conversion element according to claim 1. (7) Each pixel includes one or more organic photoelectric conversion units, The organic photoelectric conversion unit is A first electrode; a second electrode disposed opposite the first electrode; The first electrode and the second electrode are provided between the first electrode and the second electrode, a first organic semiconductor material that is a light absorber, a second organic semiconductor material that is an n-type semiconductor, and a third organic semiconductor material that is a p-type semiconductor; In the layer The third organic semiconductor material has a domain in which the third organic semiconductor material is continuously arranged. An organic photoelectric conversion layer; the third organic semiconductor material the domain has a percolation structure that crosses the organic photoelectric conversion layer in a thickness direction, and the domain length in a planar direction of the organic photoelectric conversion layer is smaller than the domain length in the thickness direction of the organic photoelectric conversion layer, The organic photoelectric conversion layer has interference fringes composed of two or more and less than ten lines in a region corresponding to one domain of the third organic semiconductor material observed in a cross-sectional photograph in a thickness direction taken by a transmission electron microscope under a defocus condition shifted about 1500 nm from a just-focus position to the underfocus side, and an angle between the interference fringes and an electrode surface of the first electrode is greater than 45° and less than 90°. Solid-state imaging device. (8) In each pixel, one or more of the organic photoelectric conversion units and one or more inorganic photoelectric conversion units that perform photoelectric conversion in a wavelength range different from that of the organic photoelectric conversion units are stacked. (7) 2. The solid-state imaging device according to claim 1 . (9) The inorganic photoelectric conversion unit is formed by embedding the inorganic photoelectric conversion unit in a semiconductor substrate, The organic photoelectric conversion section is formed on a first surface side of the semiconductor substrate. (8) 2. The solid-state imaging device according to claim 1 . (10) A multilayer wiring layer is formed on the second surface side of the semiconductor substrate. (9) 2. The solid-state imaging device according to claim 1 . (11) the organic photoelectric conversion unit performs photoelectric conversion of green light, An inorganic photoelectric conversion unit that performs photoelectric conversion of blue light and an inorganic photoelectric conversion unit that performs photoelectric conversion of red light are stacked in the semiconductor substrate. (9) or (10) above 2. The solid-state imaging device according to claim 1 . (12) In each pixel, a plurality of the organic photoelectric conversion units that perform photoelectric conversion in different wavelength ranges are stacked. Any of the above (7) to (11) 2. The solid-state imaging device according to claim 1 . [Explanation of symbols]

[0199] 1...solid-state imaging device, 10, 20...photoelectric conversion element, 11...semiconductor substrate, 11G...organic photoelectric conversion section, 11B, 11R...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...organic photoelectric conversion layer, 17...upper electrode, 18...protective layer, 19...on-chip lens layer, 19L...on-chip lens, 61...p-well, 62...gate insulating layer, 63...through electrode, 64...gate wiring layer, 70...multilayer wiring, 71, 72, 73...wiring layer, 71A...connection section, 74...insulating layer, 75...lower first contact, 76...lower second contact.

Claims

1. A first electrode; a second electrode disposed opposite the first electrode; an organic photoelectric conversion layer provided between the first electrode and the second electrode, the organic photoelectric conversion layer including a first organic semiconductor material that is a light absorber, a second organic semiconductor material that is an n-type semiconductor, and a third organic semiconductor material that is a p-type semiconductor, the organic photoelectric conversion layer having a domain in which the third organic semiconductor material is continuously arranged within the layer; a domain of the third organic semiconductor material has a percolation structure that crosses the organic photoelectric conversion layer in a thickness direction, and a domain length in a planar direction of the organic photoelectric conversion layer is smaller than a domain length in a thickness direction of the organic photoelectric conversion layer; The organic photoelectric conversion layer has interference fringes composed of two or more and less than ten lines in a region corresponding to one domain of the third organic semiconductor material observed in a cross-sectional photograph in a thickness direction taken by a transmission electron microscope under a defocus condition shifted from a just focus position to an underfocus condition of about 1500 nm, and an angle between the interference fringes and an electrode surface of the first electrode is greater than 45° and less than 90°. Photoelectric conversion element.

2. A photoelectric conversion element as described in claim 1, wherein the spacing between the two or more but less than ten lines that make up the interference fringes is within ±50% of the molecular length of the third organic semiconductor material.

3. The photoelectric conversion element according to claim 2 , wherein the length of the interference fringes is 20 nm or more.

4. The photoelectric conversion element according to claim 2 , wherein an angle between the interference fringes and an electrode surface of the first electrode is greater than 45° and equal to or smaller than 90°.

5. The photoelectric conversion element according to claim 1 , wherein a surface roughness of the interface between the organic photoelectric conversion layer and the second electrode is 10 nm or less.

6. A photoelectric conversion element as described in claim 1, wherein the third organic semiconductor material has hole transport properties.

7. Each pixel includes one or more organic photoelectric conversion units, The organic photoelectric conversion unit is A first electrode; a second electrode disposed opposite the first electrode; an organic photoelectric conversion layer provided between the first electrode and the second electrode, the organic photoelectric conversion layer including a first organic semiconductor material that is a light absorber, a second organic semiconductor material that is an n-type semiconductor, and a third organic semiconductor material that is a p-type semiconductor, the organic photoelectric conversion layer having a domain in which the third organic semiconductor material is continuously arranged within the layer; a domain of the third organic semiconductor material has a percolation structure that crosses the organic photoelectric conversion layer in a thickness direction, and a domain length in a planar direction of the organic photoelectric conversion layer is smaller than a domain length in a thickness direction of the organic photoelectric conversion layer; The organic photoelectric conversion layer has interference fringes composed of two or more and less than ten lines in a region corresponding to one domain of the third organic semiconductor material observed in a cross-sectional photograph in a thickness direction taken by a transmission electron microscope under a defocus condition shifted from a just focus position to an underfocus condition of about 1500 nm, and an angle between the interference fringes and an electrode surface of the first electrode is greater than 45° and less than 90°. Solid-state imaging device.

8. The solid-state imaging device according to claim 7 , wherein each pixel includes one or more of the organic photoelectric conversion units and one or more inorganic photoelectric conversion units that perform photoelectric conversion in a wavelength range different from that of the organic photoelectric conversion units.

9. The inorganic photoelectric conversion unit is formed by embedding the inorganic photoelectric conversion unit in a semiconductor substrate, The solid-state imaging device according to claim 8 , wherein the organic photoelectric conversion section is formed on a first surface side of the semiconductor substrate.

10. The solid-state imaging device according to claim 9 , wherein a multi-layer wiring layer is formed on the second surface side of the semiconductor substrate.

11. the organic photoelectric conversion unit performs photoelectric conversion of green light, The solid-state imaging device according to claim 9 , wherein an inorganic photoelectric conversion section that performs photoelectric conversion of blue light and an inorganic photoelectric conversion section that performs photoelectric conversion of red light are stacked in the semiconductor substrate.

12. The solid-state imaging device according to claim 7 , wherein each pixel includes a plurality of the organic photoelectric conversion units that perform photoelectric conversion in mutually different wavelength ranges.

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