Photodetector and electronic equipment

Abstract

A photodetector (1) according to an embodiment of the present disclosure is provided with: a photoelectric conversion layer (16); a first electrode (11) disposed on the side opposite a light incident side (S1) of the photoelectric conversion layer (16); a second electrode (12) disposed on the side opposite the light incident side (S1) of the photoelectric conversion layer (16) so as to be separated from the first electrode (11); a first charge transport layer (13) provided above the first electrode (11) and having a first surface (13S1) on the light incident side (S1); and a second charge transport layer (14) provided above the second electrode (12) and having a second surface (14S1) more on the light incident side (S1) than the first surface (13S1).

Description

Photodetector and electronic equipment

[0001] The present disclosure relates to a photodetector and an electronic device including the same.

[0002] For example, Patent Document 1 discloses a solid-state imaging device in which an electrode different from the lower electrodes is provided between lower electrodes provided in adjacent first and second pixels.

[0003] International Publication No. 2016 / 104177

[0004] Incidentally, in a photodetector applied to, for example, an imaging device, an improvement in quantum efficiency is required.

[0005] It would be desirable to provide photodetectors and electronic devices that allow for improved quantum efficiency.

[0006] An optical detection device according to one embodiment of the present disclosure includes a photoelectric conversion layer, a first electrode arranged on the side opposite the light incident side of the photoelectric conversion layer, a second electrode arranged on the side opposite the light incident side of the photoelectric conversion layer and spaced apart from the first electrode, a first charge transport layer arranged above the first electrode and having a first surface on the light incident side, and a second charge transport layer arranged above the second electrode and having a second surface closer to the light incident side than the first surface.

[0007] An electronic device according to an embodiment of the present disclosure includes the photodetector according to the embodiment of the present disclosure.

[0008] In a photodetector and an electronic device according to an embodiment of the present disclosure, a first electrode and a second electrode are spaced apart from each other on the side opposite the light incident side of a photoelectric conversion layer, and a first charge transport layer and a second charge transport layer are provided above the first electrode and the second electrode, respectively. When the light incident side surface of the first charge transport layer is designated as the first surface and the light incident side surface of the second charge transport layer is designated as the second surface, the second surface is formed closer to the light incident side than the first surface. This increases the amount of light incident on the photoelectric conversion layer compared to a photodetector in which the first electrode, the first charge transport layer, the photoelectric conversion layer, the second charge transport layer, and the second electrode are stacked in this order in the light incident surface direction.

[0009] FIG. 1 is a cross-sectional view schematically illustrating an example of a configuration of a photodetector according to an embodiment of the present disclosure. FIG. 2 is a block diagram illustrating the overall configuration of the photodetector shown in FIG. 1. FIG. 3 is an equivalent circuit diagram of a unit pixel shown in FIG. 1. FIG. 4 is a plan view schematic illustrating an example of a layout of a charge transport layer and a hole transport layer in a unit pixel P of the photodetector shown in FIG. 1. FIG. 5 is a cross-sectional view schematic illustrating another example of a configuration of a photodetector according to an embodiment of the present disclosure. FIG. 6A is a cross-sectional view schematic illustrating a method for manufacturing the photodetector shown in FIG. 1. FIG. 6B is a cross-sectional view schematic illustrating a step subsequent to FIG. 6A. FIG. 6C is a cross-sectional view schematic illustrating a step subsequent to FIG. 6B. FIG. 6D is a cross-sectional view schematic illustrating a step subsequent to FIG. 6C. FIG. 6E is a cross-sectional view schematic illustrating a step subsequent to FIG. 6D. FIG. 6F is a cross-sectional view schematic illustrating a step subsequent to FIG. 6E. FIG. 6G is a cross-sectional view schematic illustrating a step subsequent to FIG. 6F. FIG. 6H is a cross-sectional view schematic illustrating a step subsequent to FIG. 6G. 6I is a cross-sectional view schematically illustrating a step subsequent to FIG. 6H . FIG. 7 is a cross-sectional view schematically illustrating an example of a configuration of a photodetector according to Modification 1 of the present disclosure. FIG. 8 is a plan view schematically illustrating an example of a layout of a charge transport layer and a hole transport layer in a unit pixel P of the photodetector shown in FIG. 7 . FIG. 9 is a cross-sectional view schematically illustrating an example of a configuration of a photodetector according to Modification 2 of the present disclosure. FIG. 10 is a plan view schematically illustrating an example of a layout of a charge transport layer and a hole transport layer in a unit pixel P of the photodetector shown in FIG. 9 . FIG. 11 is a cross-sectional view schematically illustrating an example of a configuration of a photodetector according to Modification 3 of the present disclosure. FIG. 12 is a plan view schematically illustrating an example of a layout of a charge transport layer and a hole transport layer in a unit pixel P of the photodetector shown in FIG. 11 . FIG. 13 is a cross-sectional view schematically illustrating an example of a configuration of a photodetector according to Modification 4 of the present disclosure. FIG. 14 is a plan view schematically illustrating an example of a layout of a charge transport layer and a hole transport layer in a unit pixel P of the photodetector shown in FIG. 13 . Fig. 15 is a schematic cross-sectional view showing another example of the configuration of a photodetector according to Modification 4 of the present disclosure. Fig. 16 is a schematic cross-sectional view showing another example of the configuration of a photodetector according to Modification 4 of the present disclosure. Fig. 17A is a schematic cross-sectional view showing another example of the configuration of a photodetector according to Modification 4 of the present disclosure. Fig. 17B is a schematic cross-sectional view showing another example of the configuration of a photodetector according to Modification 4 of the present disclosure.FIG. 18 is a cross-sectional schematic diagram illustrating an example of the configuration of a photodetector according to Modification 5 of the present disclosure. FIG. 19 is a plan view schematic diagram illustrating an example of the layout of a charge transport layer and a hole transport layer in a unit pixel P of the photodetector shown in FIG. 18. FIG. 20 is a plan view schematic diagram illustrating an example of the layout of each unit pixel in the photodetector shown in FIG. 18. FIG. 21 is a cross-sectional schematic diagram illustrating an example of the configuration of a photodetector according to Modification 6 of the present disclosure. FIG. 22 is a plan view schematic diagram illustrating an example of the layout of a charge transport layer and a hole transport layer in a unit pixel P of the photodetector shown in FIG. 21. FIG. 23 is a cross-sectional schematic diagram illustrating another example of the configuration of a photodetector according to Modification 6 of the present disclosure. FIG. 24 is a cross-sectional schematic diagram illustrating an example of the configuration of a photodetector according to Modification 7 of the present disclosure. FIG. 25 is a plan view schematic diagram illustrating an example of the layout of a charge transport layer and a hole transport layer in a unit pixel P of the photodetector shown in FIG. 24. FIG. 26 is a cross-sectional schematic diagram illustrating an example of the configuration of a photodetector according to Modification 8 of the present disclosure. FIG. 27A is a cross-sectional view illustrating a method for manufacturing the photodetector shown in FIG. 26 . FIG. 27B is a cross-sectional view illustrating a step subsequent to FIG. 27A . FIG. 27C is a cross-sectional view illustrating a step subsequent to FIG. 27B . FIG. 27D is a cross-sectional view illustrating a step subsequent to FIG. 27C . FIG. 27E is a cross-sectional view illustrating a step subsequent to FIG. 27D . FIG. 27F is a cross-sectional view illustrating a step subsequent to FIG. 27E . FIG. 27G is a cross-sectional view illustrating a step subsequent to FIG. 27F . FIG. 28 is a cross-sectional view illustrating another example of the configuration of a photodetector according to Modification 8 of the present disclosure. FIG. 29 is a cross-sectional view illustrating another example of the configuration of a photodetector according to Modification 8 of the present disclosure. FIG. 30 is a cross-sectional view illustrating an example of the configuration of a photodetector according to Modification 9 of the present disclosure. FIG. 31 is a cross-sectional view illustrating an example of the configuration of a photodetector according to Modification 10 of the present disclosure. FIG. 32 is a cross-sectional view illustrating another example of the configuration of a photodetector according to Modification 10 of the present disclosure. Fig. 33 is a block diagram showing an example of the configuration of an electronic device using the photodetector shown in Fig. 1. Fig. 34A is a schematic diagram showing an example of the overall configuration of a photodetection system using the photodetector shown in Fig. 1. Fig. 34B is a diagram showing an example of the circuit configuration of the photodetection system shown in Fig. 34A. Fig. 35 is a diagram showing an example of the schematic configuration of an endoscopic surgery system.Fig. 36 is a block diagram showing an example of the functional configuration of a camera head and a CCU. Fig. 37 is a block diagram showing an example of a schematic configuration of a vehicle control system. Fig. 38 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit.

[0010] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following aspect. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of the components shown in the drawings. The description will be given in the following order. 1. Embodiment (Example of a photodetector in which a first electrode, a second electrode, an electron transport layer, and a hole transport layer are arranged parallel to each other in the in-plane direction) 2. Modifications 2-1. Modification 1 (Another Example of a Photodetector Configuration) 2-2. Modification 2 (Another Example of a Photodetector Configuration) 2-3. Modification 3 (Another Example of a Photodetector Configuration) 2-4. Modification 4 (Another Example of a Photodetector Configuration) 2-5. Modification 5 (Another Example of a Photodetector Configuration) 2-6. Modification 6 (Another Example of a Photodetector Configuration) 2-7. Modification 7 (Another Example of a Photodetector Configuration) 2-8. Modification 8 (Another Example of a Photodetector Configuration) 2-9. 2-10. Modification 9 (another example of the configuration of the photodetector) 3. Application example 4. Application example

[0011] 1. Embodiment Fig. 1 schematically illustrates an example of a cross-sectional configuration of a photodetector (photodetector 1) according to an embodiment of the present disclosure. Fig. 2 illustrates an example of the overall configuration of the photodetector 1 illustrated in Fig. 1. The photodetector 1 is suitably used as a CMOS (Complementary Metal Oxide Semiconductor) image sensor used in electronic devices such as digital still cameras and video cameras.

[0012] The photodetector 1 of this embodiment has a photoelectric conversion layer 16, a first electrode 11 and a second electrode 12 that are arranged on the opposite side of the photoelectric conversion layer 16 from the light incident side S1 and are spaced apart from each other, an electron transport layer 13 provided above the first electrode 11, and a hole transport layer 14 provided above the second electrode 12. The surface (surface 14S1) of the hole transport layer 14 on the light incident side S1 is formed closer to the light incident side S1 than the surface (surface 13S1) of the electron transport layer 13 on the light incident side S1.

[0013] Here, the first electrode 11 corresponds to a specific example of a "first electrode" in one embodiment of the present disclosure. The second electrode 12 corresponds to a specific example of a "second electrode" in one embodiment of the present disclosure. The electron transport layer 13 corresponds to a specific example of a "first charge transport layer" in one embodiment of the present disclosure, and the surface 13S1 corresponds to a specific example of a "first surface" in one embodiment of the present disclosure. The hole transport layer 14 corresponds to a specific example of a "second charge transport layer" in one embodiment of the present disclosure, and the surface 14S1 corresponds to a specific example of a "second surface" in one embodiment of the present disclosure. The photoelectric conversion layer 16 corresponds to a specific example of a "photoelectric conversion layer" in one embodiment of the present disclosure.

[0014] [Overall Configuration of the Photodetector] The photodetector 1 is, for example, a CMOS image sensor that captures incident light (image light) from a subject via an optical lens system (not shown), converts the amount of incident light imaged on an imaging surface into an electrical signal on a pixel-by-pixel basis, and outputs the electrical signal as a pixel signal. The photodetector 1 has a pixel section 100A as an imaging area on a semiconductor substrate 20, and also has, in a peripheral region of the pixel section 100A, for example, a vertical drive circuit 111, a column signal processing circuit 112, a horizontal drive circuit 113, an output circuit 114, a control circuit 115, and an input / output terminal 116.

[0015] The pixel section 100A has, for example, a plurality of unit pixels P arranged two-dimensionally in a matrix. For example, pixel drive lines Lread (specifically, row selection lines and reset control lines) are wired to each unit pixel P for each pixel row, and vertical signal lines Lsig are wired to each pixel column. The pixel drive lines Lread transmit drive signals for reading signals from the pixels. One end of each pixel drive line Lread is connected to an output terminal of the vertical drive circuit 111 corresponding to each row.

[0016] The vertical drive circuit 111 is a pixel drive unit that includes a shift register, an address decoder, etc., and drives each unit pixel P of the pixel unit 100A, for example, row by row. Signals output from each unit pixel P of a pixel row selected and scanned by the vertical drive circuit 111 are supplied to a column signal processing circuit 112 through each vertical signal line Lsig. The column signal processing circuit 112 is configured with an amplifier, a horizontal selection switch, etc., provided for each vertical signal line Lsig.

[0017] The horizontal drive circuit 113 is configured with a shift register, an address decoder, etc., and scans and sequentially drives each horizontal selection switch of the column signal processing circuit 112. By selective scanning by this horizontal drive circuit 113, signals of each pixel transmitted through each vertical signal line Lsig are output in sequence to horizontal signal lines 121 and transmitted to the outside of the semiconductor substrate 20 through the horizontal signal lines 121.

[0018] The output circuit 114 processes and outputs signals sequentially supplied from each of the column signal processing circuits 112 via the horizontal signal line 121. The output circuit 114 may perform only buffering, or may perform black level adjustment, column variation correction, various digital signal processing, and the like, for example.

[0019] The circuit portion consisting of the vertical drive circuit 111, the column signal processing circuit 112, the horizontal drive circuit 113, the horizontal signal line 121, and the output circuit 114 may be formed directly on the semiconductor substrate 20, or may be disposed on an external control IC. Furthermore, these circuit portions may be formed on another substrate connected by a cable or the like.

[0020] The control circuit 115 receives a clock and data instructing an operation mode from outside the semiconductor substrate 20, and outputs data such as internal information of the photodetector 1. The control circuit 115 further has a timing generator that generates various timing signals, and controls the driving of peripheral circuits such as the vertical drive circuit 111, the column signal processing circuit 112, and the horizontal drive circuit 113 based on the various timing signals generated by the timing generator.

[0021] The input / output terminal 116 is used to exchange signals with the outside.

[0022] [Circuit Configuration of Unit Pixel] FIG. 3 shows an example of a readout circuit for each unit pixel P of the photodetector 1 shown in FIG.

[0023] As described above, the pixel section 100A has a plurality of unit pixels P arranged two-dimensionally in a matrix. Each unit pixel P has one floating diffusion FD and one readout circuit.

[0024] Each unit pixel P includes, for example, a photodiode PD, a transfer transistor TR electrically connected to the photodiode PD, and a floating diffusion FD that temporarily holds the charge output from the photodiode PD via the transfer transistor TR. The photodiode PD performs photoelectric conversion to generate a charge corresponding to the amount of light received. The cathode of the photodiode PD is electrically connected to the source of the transfer transistor TR, and the anode of the photodiode PD is electrically connected to a reference potential line (e.g., ground GND). The drain of the transfer transistor TR is electrically connected to the floating diffusion FD, and the gate of the transfer transistor TR is electrically connected to a pixel drive line Lread. The transfer transistor TR is, for example, a complementary metal oxide semiconductor (CMOS) transistor.

[0025] The floating diffusion FD is electrically connected to the input terminal of the readout circuit. The readout circuit includes, for example, a reset transistor RST, a selection transistor SEL, and an amplification transistor AMP. Note that the selection transistor SEL may be omitted if necessary. The source of the reset transistor RST (the input terminal of the readout circuit) is electrically connected to the floating diffusion FD, and the drain of the reset transistor RST is electrically connected to the power supply VDD and the drain of the amplification transistor AMP. The gate of the reset transistor RST is electrically connected to the pixel drive line Lread. The source of the amplification transistor AMP is electrically connected to the drain of the selection transistor SEL, and the gate of the amplification transistor AMP is electrically connected to the source of the reset transistor RST. The source of the selection transistor SEL (the output terminal of the readout circuit) is electrically connected to the vertical signal line Lsig, and the gate of the selection transistor SEL is electrically connected to the pixel drive line Lread.

[0026] When the transfer transistor TR is turned on, it transfers the charge of the photodiode PD to the floating diffusion FD. The reset transistor RST resets the potential of the floating diffusion FD to a predetermined potential. When the reset transistor RST is turned on, it resets the potential of the floating diffusion FD to the potential of the power supply VDD. The selection transistor SEL controls the output timing of the pixel signal from the readout circuit. The amplification transistor AMP generates a pixel signal with a voltage corresponding to the level of the charge held in the floating diffusion FD. The amplification transistor AMP forms a source follower amplifier and outputs a pixel signal with a voltage corresponding to the level of the charge generated in the photodiode PD. When the selection transistor SEL is turned on, the amplification transistor AMP amplifies the potential of the floating diffusion FD and outputs a voltage corresponding to the amplified potential to the column signal processing circuit 112 via the vertical signal line Lsig. The reset transistor RST, the amplification transistor AMP, and the selection transistor SEL are, for example, CMOS transistors.

[0027] The read circuit may include, for example, an FD transfer transistor FDG, which is provided between the source of the reset transistor RST and the gate of the amplification transistor AMP.

[0028] Furthermore, the readout circuit of each unit pixel P of the photodetector 1 is not limited to the circuit configuration shown in Fig. 3. The readout circuit of each unit pixel P of the photodetector 1 may include, for example, a capacitance feedback transimpedance amplifier (CTIA). A readout circuit including a CTIA can apply a constant voltage to the photoelectric conversion layer 16 even when charge is accumulated in the photoelectric conversion layer 16, thereby stabilizing the characteristics.

[0029] [Configuration of unit pixel]

[0030] As shown in FIG. 1 , the photodetector 1 has a semiconductor substrate 20 having a pair of opposing surfaces (surfaces 20S1 and 20S2). The photodetector 1 has a photoelectric conversion unit 10 stacked on the light incident side S1 of the semiconductor substrate 20. The photoelectric conversion unit 10 absorbs light corresponding to some or all of wavelengths in a selective wavelength range (e.g., the visible light region and the near-infrared region from 900 nm to 1600 nm) and generates excitons (electron-hole pairs). Between the surface 20S1 of the semiconductor substrate 20 and the photoelectric conversion unit 10, an insulating layer 25 and interlayer insulating layers 26, 27, and 28 are stacked in this order on the surface 20S1 side. A protective layer 17 is provided on the light incident side S1 of the photoelectric conversion unit 10, and an optical member such as an on-chip lens 18 is disposed on the protective layer 17. In the photodetector 1, of the electron-hole pairs generated by photoelectric conversion, for example, electrons are read out from the first electrode 11 as signal charges. In the following, the configuration and materials of each part will be described, taking as an example a case where electrons are read out as signal charges from the first electrode 11.

[0031] FIG. 4 is a schematic diagram illustrating an example of a planar layout of the electron transport layer 13 and the hole transport layer 14 in the unit pixel P of the photodetector 1 shown in FIG. 1 . Note that FIG. 1 illustrates a cross section corresponding to line II′ in FIG. 4 . The photoelectric conversion unit 10 includes a first electrode 11, a second electrode 12, an electron transport layer 13, a hole transport layer 14, an insulating film 15, and a photoelectric conversion layer 16. The first electrode 11 and the second electrode 12 are arranged in parallel in the XY plane direction in which the photoelectric conversion layer 16 extends. Specifically, the first electrode 11 is provided approximately in the center of the unit pixel P, and the second electrode 12 is provided between adjacent unit pixels P, for example, so as to surround the first electrode 11. In other words, the first electrode 11 is provided for each unit pixel P. The second electrodes 12 are provided between adjacent unit pixels P in the row direction (e.g., the X-axis direction) and the column direction (e.g., the Y-axis direction), and the pixel section 100A as a whole is provided in a lattice pattern in a plan view. An insulating film (e.g., an interlayer insulating layer 28) is provided between the first electrodes 11 and the second electrodes 12, electrically isolating them from each other. The electron transport layer 13 is provided on the first electrode 11, and the hole transport layer 14 is provided on the second electrode 12. Specifically, the electron transport layer 13 is provided approximately at the center of the unit pixel P, similar to the first electrode 11, and the hole transport layer 14 is provided between adjacent unit pixels P, for example, surrounding the electron transport layer 13, similar to the second electrode 12. In other words, the electron transport layer 13 is provided for each unit pixel P. The hole transport layer 14 is provided between adjacent unit pixels P in the row direction (e.g., the X-axis direction) and the column direction (e.g., the Y-axis direction), and the pixel section 100A as a whole is provided in a lattice pattern in a plan view. An insulating film (e.g., insulating film 15) is provided between the electron transport layer 13 and the hole transport layer 14, electrically isolating them from each other. That is, the first electrode 11 and the electron transport layer 13, and the second electrode 12 and the hole transport layer 14, are each formed in approximately the same layout, and the planar layout of the electron transport layer 13 and the hole transport layer 14 shown in FIG. 4 can be regarded as the planar layout of the first electrode 11 and the second electrode 12. The photoelectric conversion layer 16 is formed to extend in the XY plane so as to cover the electron transport layer 13, the hole transport layer 14, and the insulating film 15.In other words, the photoelectric conversion layer 16 is disposed closest to the light incident side S1 among the components constituting the photoelectric conversion unit 10. That is, the photodetector 1 of this embodiment is configured so that light incident on the on-chip lens 18 directly enters the photoelectric conversion layer 16 without passing through the other components constituting the photoelectric conversion unit 10 (the first electrode 11, the second electrode 12, the electron transport layer 13, the hole transport layer 14, and the insulating film 15).

[0032] In the photodetector 1 of this embodiment, the surface 13S1 on the light incident side S1 of the electron transport layer 13 and the surface 14S1 on the light incident side S1 of the hole transport layer 14 are formed at different positions from each other in the stacking direction (Z-axis direction). Specifically, as described above, the surface 14S1 of the hole transport layer 14 is formed closer to the light incident side S1 than the surface 13S1 of the electron transport layer 13. More specifically, in the photodetector 1, the first electrode 11 and the second electrode 12 are arranged in parallel in an in-plane direction (e.g., the XY plane direction) in which the photoelectric conversion layer 16 extends. When the film thickness of the electron transport layer 13 is d1 and the film thickness of the hole transport layer 14 is d2, the hole transport layer 14 has a film thickness greater than that of the electron transport layer 13 (d2>d1), and a portion of the hole transport layer 14 protrudes into the photoelectric conversion layer 16. In other words, when the height from the upper surfaces of the first electrode 11 and the second electrode 12 to the surface (surface 16S1) on the light incident side S1 of the photoelectric conversion layer 16 is defined as d3, the heights of the electron transport layer 13, the hole transport layer 14, and the photoelectric conversion layer 16 have a relationship of, for example, d3 > d2 > d1. Note that the relationship in height between the electron transport layer 13, the hole transport layer 14, and the photoelectric conversion layer 16 is not limited thereto. FIG. 5 schematically illustrates another example of the cross-sectional configuration of a photodetector (photodetector 1) according to an embodiment of the present disclosure. The hole transport layer 14 may have its upper surface (surface 14S1) formed within the photoelectric conversion layer 16, or may penetrate the photoelectric conversion layer 16 and be flush with the upper surface (surface 16S1) of the photoelectric conversion layer 16, as shown in FIG. 5. In this case, the heights of the electron transport layer 13, the hole transport layer 14, and the photoelectric conversion layer 16 satisfy the relationship d3 = d2 > d1. Furthermore, although not shown, the hole transport layer 14 may protrude toward the light incident side S1 from the upper surface (surface 16S1) of the photoelectric conversion layer 16. In this case, the heights of the electron transport layer 13, the hole transport layer 14, and the photoelectric conversion layer 16 satisfy the relationship d2>d3>d1.

[0033] The first electrode 11 and the second electrode 12 are each made of, for example, a light-transmitting conductive film. The first electrode 11 and the second electrode 12 are made of, for example, InP doped with tin (Sn) as a dopant. ２ O ３ In addition to the above, the first electrode 11 and the second electrode 12 may also be made of tin oxide (SnO ２ )-based materials, for example, ATO with Sb added as a dopant, and FTO with fluorine added as a dopant. Zinc oxide (ZnO) or a zinc oxide-based material with a dopant added thereto may also be used. Examples of ZnO-based materials include aluminum zinc oxide (AZO) with aluminum (Al) added as a dopant, gallium zinc oxide (GZO) with gallium (Ga) added, boron zinc oxide with boron (B) added, and indium zinc oxide (IZO) with indium (In) added. Furthermore, zinc oxide with indium and gallium added as dopants (IGZO, In-GaZnO ４ In addition, the first electrode 11 and the second electrode 12 may be made of CuI, InSbO ４ , ZnMgO, CuInO ２ , MgIN ２ O ４ , CdO, ZnSnO ３ or TiO ２ Alternatively, spinel oxides or YbFe ２ O ４ Oxides having such a structure may also be used.

[0034] When optical transparency is not required for the first electrode 11 and the second electrode 12, for example, one of the electrodes can be a single metal or alloy having a low work function (e.g., φ=3.5 eV to 4.5 eV) and the other can be a single metal or alloy having a high work function (e.g., φ=4.5 eV to 5.5 eV). Examples of single metals or alloys having a low work function include alkali metals (e.g., lithium (Li), sodium (Na), and potassium (K)) and their fluorides or oxides, and alkaline earth metals (e.g., magnesium (Mg) and calcium (Ca)) and their fluorides or oxides. Other examples include aluminum (Al), Al—Si—Cu alloys, zinc (Zn), tin (Sn), thallium (Tl), Na—K alloys, Al—Li alloys, Mg—Ag alloys, and rare earth metals such as In and ytterbium (Yb), or alloys thereof. Examples of single metals or alloys having a high work function include Au, Ag, Cr, Ni, Pd, Pt, Fe, iridium (Ir), germanium (Ge), osmium (Os), rhenium (Re), tellurium (Te), and alloys thereof.

[0035] The first electrode 11 and the second electrode 12 can be formed using the same material even when optical transparency is not required. Examples of materials that can be used to form the first electrode 11 and the second electrode 12 include metals such as platinum (Pt), gold (Au), palladium (Pd), chromium (Cr), nickel (Ni), aluminum (Al), silver (Ag), tantalum (Ta), tungsten (W), copper (Cu), titanium (Ti), indium (In), tin (Sn), iron (Fe), cobalt (Co), and molybdenum (Mo), alloys containing these metal elements, conductive particles made of these metals, conductive particles of alloys containing these metals, polysilicon containing impurities, carbon-based materials, oxide semiconductors, carbon nanotubes, and graphene. Other examples of materials that can be used to form the first electrode 11 and the second electrode 12 include organic materials (conductive polymers) such as poly(3,4-ethylenedioxythiophene) / polystyrenesulfonic acid [PEDOT / PSS]. Furthermore, the above materials may be mixed with a binder (polymer) to form a paste or ink, which may then be hardened and used as an electrode.

[0036] The first electrode 11 and the second electrode 12 can be formed as a single layer film or a laminated film made of the above-mentioned materials. The film thickness of the first electrode 11 and the second electrode 12 in the lamination direction (hereinafter simply referred to as thickness) is, for example, 10 nm to 500 nm, and preferably 10 nm to 150 nm.

[0037] The electron transport layer 13 selectively transports electrons, among the charge carriers generated in the photoelectric conversion layer 16, to the first electrode 11, while inhibiting the injection of holes from the first electrode 11 side. The electron transport layer 13 can be formed using an organic compound, an oxide semiconductor, or semiconductor nanoparticles. An n-type semiconductor is preferable as the organic compound, and examples thereof include organometallic dyes formed as complexes between transition metal ions, such as zinc phthalocyanine (II), and organic materials. Other examples of n-type semiconductors include fullerenes or derivatives thereof, and non-fullerene acceptors, such as ITIC derivatives and BTP derivatives. Examples of oxide semiconductors and semiconductor nanoparticles include titanium oxide (TiO２ ), zinc oxide, zinc sulfide (ZnS), SrTiO ３ , niobium oxide (Nb ２ O ５ ), tungsten oxide (WO ３ ), indium oxide (In ２ O ３ ), CuTiO ３ , tin oxide (SnO ２ ), InGaZnO4, InTiO ２ and β-Ga ２ O ３ and other inorganic materials.

[0038] The hole transport layer 14 selectively transports holes, among the charge carriers generated in the photoelectric conversion layer 16, to the second electrode 12, while inhibiting the injection of electrons from the second electrode 12. The hole transport layer 14 can be formed using an organic compound, an oxide semiconductor, or semiconductor nanoparticles. Examples of organic compounds include P3HT (poly(3-hexylthiophene-2,5-diyl)), SPIRO-OMeTAD, 2T-NATA, PTB7, PBTB-T, V886, PTB7-Th, Poly-TPD, and PBDB-T-2F. Examples of oxide semiconductors and semiconductor nanoparticles include nickel oxide, and compound semiconductors of Group IV, Group I-III-VI, or Group I-II-III-VI. Examples of Group IV semiconductor nanoparticles include Ag. ２ S and Ag ２ The semiconductor nanoparticles of the I-III-VI group include, for example, AgInS ２ , AgInSe ２ , AgInTe ２ , CuInS ２ , CuInSe ２ and CuInTe ２ Group I-II-III-VI semiconductor nanoparticles include, for example, ZnCuInS and ZnCuInSe.

[0039] The insulating film 15 is provided on each of the first electrode 11 and the second electrode 12, and serves to electrically separate the electron transport layer 13 and the hole transport layer 14, which are arranged in parallel in the XY plane direction. The insulating film 15 is made of, for example, silicon oxide (SiOｘ ), silicon nitride (SiN ｘ ) and silicon oxynitride (SiO ｘ N ｙ ) or a laminated film made of two or more of them.

[0040] The photoelectric conversion layer 16 converts light energy into electrical energy and separates charges by absorbing, for example, 60% or more of predetermined wavelengths included at least in the visible light region to the near-infrared region. The photoelectric conversion layer 16 absorbs, for example, 20% or more of light having wavelengths in the visible light region and part or all of the near-infrared light region from 900 nm to 1600 nm. The photoelectric conversion layer 16 is configured to include, for example, quantum dots. Specific examples of quantum dots include lead sulfide (PbS) quantum dots, lead selenide (PbSe) quantum dots, lead telluride (PbTe) quantum dots, mercury telluride (HgTe) quantum dots, indium phosphide (InP) quantum dots, indium arsenide (InAs) quantum dots, indium antimonide (InSb) quantum dots, cadmium sulfide (CdS) quantum dots, cadmium selenide (CdSe) quantum dots, and cadmium telluride (CsTe) quantum dots. Alternatively, the photoelectric conversion layer 16 may be formed using an organic compound semiconductor or an organic-inorganic perovskite.

[0041] The thickness of the photoelectric conversion layer 16 is, for example, 50 nm or more and 1 μm or less, and preferably 100 nm or more and 700 nm or less.

[0042] In the photodetector 1, light incident on the photoelectric conversion unit 10 is absorbed in the photoelectric conversion layer 16. The resulting excitons dissociate into electrons and holes. The charge carriers (electrons and holes) generated here are transported to the corresponding electrodes by diffusion due to a difference in charge carrier concentration, the difference in work function between the anode (e.g., the second electrode 12) and the cathode (e.g., the first electrode 11), and an internal electric field due to a difference in height in the Z-axis direction between the electron transport layer 13 and the hole transport layer 14, and are detected as a photocurrent. The transport directions of the electrons and holes are controlled by applying predetermined potentials to the first electrode 11 and the second electrode 12, respectively.

[0043] The semiconductor substrate 20 is made of, for example, an n-type silicon (Si) substrate. A surface 20S1 of the semiconductor substrate 20 is provided with, for example, a floating diffusion FD (region 21C in the semiconductor substrate 20), an amplifier transistor AMP, a reset transistor RST, a select transistor SEL, and an element isolation region 24. A peripheral circuit (not shown) including a logic circuit and the like is provided in a peripheral portion 100B of the semiconductor substrate 20.

[0044] The reset gate 21 of the reset transistor RST is disposed next to the floating diffusion FD (region 21B), which allows the charge carriers stored in the floating diffusion FD to be reset by the reset transistor RST.

[0045] The reset transistor RST resets the charge carriers transferred from the photoelectric conversion unit 10 to the floating diffusion FD, and is composed of, for example, a MOS transistor. Specifically, the reset transistor RST is composed of a reset gate 21, a channel formation region 21A, and source / drain regions 21B and 21C. The reset gate 21 is connected to a reset line, and one source / drain region 21C of the reset transistor RST also serves as the floating diffusion FD. The other source / drain region 21B constituting the reset transistor RST is connected to a power supply VDD.

[0046] The amplifier transistor AMP is a modulation element that modulates the amount of charge generated in the photoelectric conversion unit 10 into a voltage and is configured, for example, by a MOS transistor. Specifically, the amplifier transistor AMP is configured with an amplifier gate 22, a channel formation region 22A, and source / drain regions 22B and 22C. The amplifier gate 22 is connected to the first electrode 11 and one of the source / drain regions 21C (floating diffusion FD) of the reset transistor RST via a via and through-wiring 31 provided in an interlayer insulating layer 26, wiring 32 and through-wiring 33 provided in an interlayer insulating layer 27, and wiring 34 and contacts 35 provided in an interlayer insulating layer 28. The one of the source / drain regions 22C shares an area with the other of the source / drain regions 21B constituting the reset transistor RST and is connected to a power supply VDD.

[0047] The select transistor SEL is composed of a select gate 23, a channel formation region 23A, and source / drain regions 23B and 23C. The select gate 23 is connected to a select line. One source / drain region 23V shares an area with the other source / drain region 22B that constitutes the amplifier transistor AMP, and the other source / drain region 23B is connected to a signal line (data output line) VSL.

[0048] The reset line and the selection line are each connected to a row scanning section 131 that constitutes a driving circuit. The signal line (data output line) VSL is connected to a horizontal selection section 133 that constitutes a driving circuit.

[0049] The element isolation region 24 has an STI (Shallow Trench Isolation) structure and is made of, for example, silicon oxide.

[0050] The insulating layer 25 may be a film having a positive fixed charge or a film having a negative fixed charge. Examples of materials for a film having a negative fixed charge include hafnium oxide (HfO ｘ ), aluminum oxide (AlO ｘ ), zirconium oxide (ZrO ｘ ), tantalum oxide (TaO ｘ), titanium oxide (TiO ｘ Other examples of the material for the insulating layer 25 include lanthanum oxide (LaO ｘ ), praseodymium oxide (PrO ｘ ), cerium oxide (CeO ｘ ), neodymium oxide (NdO ｘ ), promethium oxide (PmO ｘ ), samarium oxide (SmO ｘ ), europium oxide (EuO ｘ ), gadolinium oxide (GdO ｘ ), terbium oxide (TbO ｘ ), dysprosium oxide (DyO ｘ ), holmium oxide (HoO ｘ ), thulium oxide (TmO ｘ ), ytterbium oxide (YbO ｘ ), lutetium oxide (LuO ｘ ), yttrium oxide (YO ｘ ), hafnium nitride (HfN ｘ ), aluminum nitride (AlN ｘ ), hafnium oxynitride (HfO ｘ N ｙ ) and aluminum oxynitride (AlO ｘ N ｙ ) etc.

[0051] The interlayer insulating layers 26, 27, and 28 are made of, for example, silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ) and silicon oxynitride (SiO ｘ N ｙ ) or a laminated film made of two or more of these.

[0052] The reset gate 21, the amplifier gate 22, the select gate 23, the through wirings 31 and 33, the wirings 32 and 34, and the contacts 35 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), or tantalum (Ta).

[0053] The protective layer 17 is made of a light-transmitting material, such as silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ) and silicon oxynitride (SiO ｘ N ｙ ) or a laminated film made of two or more of them. The thickness of the protective layer 17 is, for example, 10 nm to 1 μm. Like the protective layer 17, the on-chip lens 18 is made of a light-transmitting material.

[0054] [Method of Manufacturing Photodetector] The photodetector 1 can be manufactured, for example, as follows: Figures 6A to 6I show an example of a manufacturing process for the photodetector 1.

[0055] 6A , a wiring layer including each transistor constituting the readout circuit is formed by the FEOL process on the surface 20S1 of the semiconductor substrate 20. Subsequently, an interlayer insulating layer 27 including the wiring 32 and the through wiring 33, a wiring 34, a contact 35, and an interlayer insulating layer 28 including the first electrode 11 and the second electrode 12 are formed by the BEOL process.

[0056] Next, as shown in Fig. 6B, an insulating film 15 is formed on the interlayer insulating layer 28 including the first electrode 11 and the second electrode 12, for example, by chemical vapor deposition (CVD). Subsequently, as shown in Fig. 6C, a resist film 201 is formed in a predetermined pattern on the insulating film 15, for example, by photolithography. Next, as shown in Fig. 6D, the insulating film 15 is processed, for example, by dry etching, to form openings 15H above the first electrode 11 and the second electrode 12, respectively, and the first electrode 11 and the second electrode 12 are exposed at the bottoms of the openings 15H.

[0057] 6E, a film to become the electron transport layer 13 is formed by, for example, sputtering or CVD, and then the electron transport layer 13 is formed on the first electrode 11 by, for example, photolithography and etching. Next, as shown in Fig. 6F, a film to become the hole transport layer 14 is formed by, for example, sputtering or CVD, and then the hole transport layer 14 is formed on the second electrode 12 by, for example, photolithography and etching. Next, as shown in Fig. 6G, a photoelectric conversion layer 16 is formed continuously on the electron transport layer 13, the hole transport layer 14, and the insulating film 15 by, for example, spin coating.

[0058] Next, as shown in Fig. 6H, a protective layer 17 is formed on the photoelectric conversion layer 16 by, for example, a CVD method. Finally, as shown in Fig. 6I, an on-chip lens 18 is disposed on the protective layer 17. In this manner, the photodetector 1 shown in Fig. 1 is completed.

[0059] [Operations and Effects] In the photodetector 1 according to this embodiment, the first electrode 11 and the second electrode 12 are arranged in parallel on the side opposite the light incident side S1 of the photoelectric conversion layer 16, and the electron transport layer 13 and the hole transport layer 14 are provided on the first electrode 11 and the second electrode 12, respectively. The electron transport layer 13 and the hole transport layer 14 have different film thicknesses. For example, the upper surface (surface 13S1) of the electron transport layer 13 contacts the photoelectric conversion layer 16, and a portion of the hole transport layer 14 protrudes into the photoelectric conversion layer. This allows light incident on the on-chip lens 18 to directly enter the photoelectric conversion layer 16 without passing through the other components (the first electrode 11, the second electrode 12, the electron transport layer 13, the hole transport layer 14, and the insulating film 15) that make up the photoelectric conversion unit 10, thereby increasing the amount of light incident on the photoelectric conversion layer 16. This is described below.

[0060] Image sensors using photoelectric conversion films such as quantum dots or organic semiconductors generally have a structure in which the photoelectric conversion film is disposed between a pair of electrodes arranged opposite each other in the stacking direction. In such image sensors, the electrode arranged on the light incident side is formed of a transparent conductive film, and signal charges generated by photoelectric conversion are collected by applying a voltage to the pair of electrodes.

[0061] However, in an image sensor having the above-described laminated structure, before light incident through the lens reaches the photoelectric conversion film, light is lost due to absorption or reflection of light in an electrode (transparent electrode) formed of a transparent conductive film, a charge transport layer formed between the transparent electrode and the photoelectric conversion film, etc. This light loss is not considered a problem because it is minute in general image sensors that detect wavelengths in the visible light region, but it becomes an issue in image sensors that detect wavelengths in the near-infrared region or short-wave infrared region of 900 nm or more, for example.

[0062] In contrast, in the present embodiment, as described above, the first electrode 11 and the second electrode 12 are arranged in parallel on the side opposite to the light incident side S1 of the photoelectric conversion layer 16, and the electron transport layer 13 and the hole transport layer 14 are provided on the first electrode 11 and the second electrode 12, respectively. As a result, light incident on the on-chip lens 18 is incident directly on the photoelectric conversion layer 16 without passing through other members (the first electrode 11, the second electrode 12, the electron transport layer 13, the hole transport layer 14, and the insulating film 15) that constitute the photoelectric conversion unit 10. In other words, as described above, compared to a general image sensor in which a transparent electrode, a charge transport layer, etc. are stacked on a photoelectric conversion film, the amount of light incident on the photoelectric conversion layer 16 is reduced, and therefore the amount of light incident on the photoelectric conversion layer 16 is increased.

[0063] As a result, the photodetector 1 of this embodiment can improve quantum efficiency.

[0064] Furthermore, as mentioned above, in a typical image sensor in which a photoelectric conversion film is disposed between a pair of electrodes arranged opposite each other in the stacking direction, lateral leakage between adjacent pixels is an issue. This lateral leakage is caused by the in-plane movement of electrons and holes generated by exciton dissociation after photoelectric conversion, and is expected to become a bigger issue as pixels are further miniaturized.

[0065] In contrast, in the present embodiment, a hole transport layer 14 is provided between adjacent unit pixels P. When the thickness of the electron transport layer 13 is d1 and the thickness of the hole transport layer 14 is d2, the hole transport layer 14 has a thickness greater than that of the electron transport layer 13 (d2>d1), and a portion of the hole transport layer 14 protrudes into or penetrates the photoelectric conversion layer 16. This generates a two-dimensional or three-dimensional internal electric field within the photoelectric conversion layer 16, improving the readout efficiency of signal charges generated in each unit pixel P. Additionally, the hole transport layer 14 provided between adjacent unit pixels P functions as an inter-pixel separator, suppressing the movement of electrons and holes to adjacent pixels. This reduces lateral leakage between adjacent pixels, making it possible to realize a higher-resolution photodetector device, for example, with a pixel size of 10 μm or less.

[0066] Furthermore, as described above, a typical image sensor in which a photoelectric conversion film is disposed between a pair of electrodes arranged opposite each other in the stacking direction has the following two problems. The first problem is the variation in characteristics between pixels or within a pixel due to variations in the film formation process of the transparent electrode. The second problem is that when quantum dots are used in the photoelectric conversion film, the selection of materials for the charge transport layer and transparent electrode formed on the photoelectric conversion film becomes limited and film formation becomes more difficult.

[0067] In contrast, in the present embodiment, the photoelectric conversion layer 16 can be deposited last of the components constituting the photoelectric conversion unit 10. As a result, in the photodetector 1 of the present embodiment, it is possible to reduce variations in the film deposition process of the first electrode 11 and the second electrode 12, thereby reducing variations in characteristics between pixels and within a pixel. Furthermore, in the photodetector 1 of the present embodiment, it is possible to improve the degree of freedom in the selection of materials for the components constituting the photoelectric conversion unit 10 and in the manufacturing process.

[0068] Next, modifications 1 to 10 of the present disclosure will be described. In the following, the same components as those in the above embodiment will be given the same reference numerals, and the description thereof will be omitted as appropriate.

[0069] <2. Modifications> (2-1. Modification 1) Fig. 7 is a schematic diagram showing an example of a cross-sectional configuration of a photodetector (photodetector 1A) according to Modification 1 of the present disclosure. Fig. 8 is a schematic diagram showing an example of a planar layout of the electron transport region 110 and the hole transport region 120 in a unit pixel P of the photodetector 1A shown in Fig. 7, and Fig. 7 shows a cross section corresponding to line II-II' shown in Fig. 8. The photodetector 1A is suitably used as a CMOS image sensor or the like used in electronic devices such as digital still cameras and video cameras.

[0070] The photodetector 1A of this modification has a first electrode 11 and an electron transport layer 13 provided thereon, and a second electrode 12 and a hole transport layer 14 provided thereon, which are repeatedly and periodically arranged. As an example, the photodetector 1A has a configuration in which two electron transport sections 110 (electron transport sections 110A and 110B) each consisting of a first electrode 11 and an electron transport layer 13 provided thereon, and two hole transport sections 120 (hole transport sections 120A and 120B) each consisting of a second electrode 12 and a hole transport layer 14 provided thereon, are alternately arranged from approximately the center of the unit pixel P toward the periphery. The electron transport sections 110A and 110B and the hole transport sections 120A and 120B are each connected to, for example, a common power supply or readout circuit (ROIC) and can be driven simultaneously. Except for this point, the photodetector 1A has substantially the same configuration as the photodetector 1 of the above embodiment.

[0071] 7 and 8 show an example in which two electron transport sections 110 (electron transport sections 110A and 110B) and two hole transport sections 120 (hole transport sections 120A and 120B) are repeatedly and periodically arranged, but the present invention is not limited to this. Three or more electron transport sections 110 and three or more hole transport sections 120 may be repeatedly and periodically arranged.

[0072] In this manner, in the photodetector 1A of this modification, the first electrode 11 and the electron transport layer 13 provided thereon, and the second electrode 12 and the hole transport layer 14 provided thereon are repeatedly and periodically arranged. This allows charge carriers (electrons and holes) generated within the surface of the photoelectric conversion layer 16 to be efficiently collected, thereby enabling a greater improvement in quantum efficiency compared to the photodetector of the above embodiment. Note that this configuration is expected to be more effective in photodetector devices with large pixel sizes.

[0073] (2-2. Modification 2) Fig. 9 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector (photodetector 1B) according to Modification 2 of the present disclosure. Fig. 10 is a schematic diagram illustrating an example of a planar layout of the electron transport region 110 and the hole transport region 120 in a unit pixel P of the photodetector 1B illustrated in Fig. 9, and Fig. 9 illustrates a cross section corresponding to line III-III' illustrated in Fig. 10. The photodetector 1B is suitably used as a CMOS image sensor or the like for use in electronic devices such as digital still cameras and video cameras.

[0074] In the above embodiment, an example in which one first electrode 11 and one electron transport layer 13 are provided approximately at the center of the unit pixel P has been described, but the present invention is not limited to this. In the photodetector 1B of this modification, two electron transport sections 110 (electron transport sections 110A and 110B) each consisting of a first electrode 11 and an electron transport layer 13 provided thereover are arranged in parallel with an insulating film 15 between them, for example, in the Y-axis direction, approximately at the center of the unit pixel P. The two electron transport sections 110 (electron transport sections 110A and 110B) are electrically isolated from each other by the insulating film 15. Except for this point, the photodetector 1B has substantially the same configuration as the photodetector 1 of the above embodiment.

[0075] In this manner, in the photodetector 1B of this modification, the two electron transport sections 110 (electron transport sections 110A and 110B) are arranged in parallel with the insulating film 15 between them at approximately the center of the unit pixel P. Even with this configuration, the photodetector 1B of this modification can achieve the same effects as those of the above-described embodiment and modification 1.

[0076] (2-3. Modification 3) Fig. 11 is a schematic diagram showing an example of a cross-sectional configuration of a photodetector (photodetector 1C) according to Modification 3 of the present disclosure. Fig. 12 is a schematic diagram showing an example of a planar layout of the electron transport region 110 and the hole transport region 120 in a unit pixel P of the photodetector 1C shown in Fig. 11, and Fig. 11 shows a cross section corresponding to line IV-IV' shown in Fig. 12. The photodetector 1C is suitable for use as a CMOS image sensor or the like used in electronic devices such as digital still cameras and video cameras.

[0077] In the above-described second modification, an example was shown in which two electron transport sections 110 (electron transport sections 110A and 110B) were arranged in parallel with an insulating film 15 between them at approximately the center of the unit pixel P, but the present invention is not limited to this. In a photodetector 1C of this modification, two electron transport sections 110 (electron transport sections 110A and 110B) each consisting of a first electrode 11 and an electron transport layer 13 provided thereover are arranged in parallel with an insulating film 15 and a hole transport section 120 between them at approximately the center of the unit pixel P, for example, in the Y-axis direction. The two electron transport sections 110 (electron transport sections 110A and 110B) are electrically isolated from each other by the insulating film 15 and the hole transport section 120. Except for this point, the photodetector 1C has substantially the same configuration as the photodetector 1 of the above-described embodiment.

[0078] In this manner, in the photodetector 1C of this modified example, the two electron transport sections 110 (electron transport sections 110A and 110B) are arranged in parallel with the insulating film 15 and the hole transport section 120 therebetween at approximately the center of the unit pixel P. Even with this configuration, the photodetector 1C of this modified example can achieve the same effects as those of the above-described embodiment and modified example 1.

[0079] (2-4. Modification 4) FIG. 13 is a schematic diagram showing an example of a cross-sectional configuration of a photodetector according to Modification 4 of the present disclosure (photodetector 1D). FIG. 14 is a schematic diagram showing an example of a planar layout of the electron transport layer 13 and the hole transport layer 14 in a unit pixel P of the photodetector 1D shown in FIG. 13, and FIG. 13 shows a cross section corresponding to the VV' line shown in FIG. 14. FIG. 15 is a schematic diagram showing another example of a cross-sectional configuration of a photodetector according to Modification 4 of the present disclosure (photodetector 1M). The photodetectors 1D and 1M are suitable for use as CMOS image sensors used in electronic devices such as digital still cameras and video cameras, for example.

[0080] In the photodetector 1D of this modified example, a functional layer 19A is provided between the hole transport layer 14 and the photoelectric conversion layer 16. In the photodetector 1M of this modified example, a functional layer 19B is provided between the electron transport layer 13 and the photoelectric conversion layer 16. Except for this point, the photodetectors 1D and 1M each have substantially the same configuration as the photodetector 1 of the above embodiment.

[0081] The functional layer 19A is a layer having various functions. For example, the functional layer 19A is a so-called electron blocking layer that inhibits the injection of electrons from the second electrode 12 into the photoelectric conversion layer 16. In addition, the functional layer 19A has an electron affinity or work function greater than the work function of the second electrode 12, and is a so-called work function adjustment layer that improves the electrical connection between the second electrode 12 and the hole transport layer 14. Alternatively, the functional layer 19A is a protective film that protects the processed surface of the photoelectric conversion layer 16 when the photoelectric conversion layer 16 is processed.

[0082] The functional layer 19B is a layer having various functions, similar to the functional layer 19A. For example, the functional layer 19B is a so-called hole blocking layer that inhibits the injection of holes from the first electrode 11 into the photoelectric conversion layer 16. In addition, the functional layer 19B has an electron affinity or work function greater than the work function of the first electrode 11, and is a so-called work function adjustment layer that improves the electrical connection between the first electrode 11 and the electron transport layer 13. Alternatively, the functional layer 19B is a protective film that protects the processed surface of the photoelectric conversion layer 16 when the photoelectric conversion layer 16 is processed.

[0083] The functional layers 19A and 19B can each be formed using an organic compound, an oxide semiconductor, or semiconductor nanoparticles.

[0084] When the functional layer 19A is provided on the side surface of the hole transport layer 14, it is preferable that the hole transport layer 14 be provided wider than the second electrode 12 as shown in FIG.

[0085] In this manner, in the photodetector 1D of this modified example, the functional layer 19A is provided between the hole transport layer 14 and the photoelectric conversion layer 16. In the photodetector 1M of this modified example, the functional layer 19B is provided between the electron transport layer 13 and the photoelectric conversion layer 16. Even with such a configuration, the photodetectors 1D and 1M of this modified example can achieve the same effects as those of the above-described embodiment.

[0086] Furthermore, the photodetector 1D and the photodetector 1M can be combined with each other. For example, the photodetector 1N shown in Fig. 16 has functional layers 19A and 19B provided between the hole transport layer 14 and the photoelectric conversion layer 16, and between the electron transport layer 13 and the photoelectric conversion layer 16, respectively. Even with this configuration, the photodetector 1N can achieve the same effects as those of the above-described embodiment.

[0087] Furthermore, although Fig. 13 shows an example in which a functional layer 19A is provided between the hole transport layer 14 and the photoelectric conversion layer 16, and Fig. 15 shows an example in which a functional layer 19B is provided between the electron transport layer 13 and the photoelectric conversion layer 16, the present invention is not limited thereto. When the functional layer 19A functions as a work function adjustment layer as described above, it is preferable that the functional layer 19A is provided on the second electrode 12 and the hole transport layer 14 is provided on its side, as shown in Fig. 17A. When the functional layer 19B functions as a work function adjustment layer as described above, it is preferable that the functional layer 19B is provided between the first electrode 11 and the electron transport layer 13, as shown in Fig. 17B. In this way, the positions of the functional layer 19A and the hole transport layer 14 and the positions of the functional layer 19B and the electron transport layer 13 may be interchanged as appropriate.

[0088] Furthermore, other layers may be provided between the first electrode 11 and the electron transport layer 13, between the electron transport layer 13 and the photoelectric conversion layer 16, between the second electrode and the hole transport layer 14, and between the hole transport layer 14 and the photoelectric conversion layer 16. In any of the configurations, the photodetector of this modified example can obtain the same effects as those of the above embodiment.

[0089] (2-5. Modification 5) Fig. 18 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector (photodetector 1E) according to Modification 5 of the present disclosure. Fig. 19 is a schematic diagram illustrating an example of a planar layout of the electron transport region 110 and the hole transport region 120 in a unit pixel P of the photodetector 1E illustrated in Fig. 18, and Fig. 18 illustrates a cross section corresponding to line VI-VI' illustrated in Fig. 19. The photodetector 1E is suitable for use as a CMOS image sensor or the like used in electronic devices such as digital still cameras and video cameras.

[0090] In the above-mentioned variant example 3, an example was shown in which two electron transport sections 110 (electron transport sections 110A and 110B) were arranged in parallel at approximately the center of the unit pixel P with an insulating film 15 and a hole transport section 120 between them, but the two electron transport sections 110A and 110B arranged in parallel within the unit pixel P can each be used as image plane phase difference pixels PA and PB by individually reading out the signal charges.

[0091] In addition, when the electron transport sections 110A and 110B are used as image plane phase difference pixels PA and PB, the arrangement direction of the electron transport sections 110A and 110B within the unit pixel P may be arranged alternately in the row direction (e.g., the X-axis direction) and the column direction (e.g., the Y-axis direction), as shown in, for example, FIG. 20 .

[0092] (2-6. Modification 6) Fig. 21 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector (photodetector 1F) according to Modification 6 of the present disclosure. Fig. 22 is a schematic diagram illustrating an example of a planar layout of the electron transport layer 13 and the hole transport layer 14 in a unit pixel P of the photodetector 1F illustrated in Fig. 21, and Fig. 21 illustrates a cross section corresponding to line VII-VII' illustrated in Fig. 22. The photodetector 1D is suitably used as a CMOS image sensor or the like for use in electronic devices such as digital still cameras and video cameras.

[0093] The photodetector 1F of this modified example is provided with an insulating film 151 that separates adjacent unit pixels P, and a second electrode 12 and a hole transport layer 14 are provided for each unit pixel P. Except for this point, the photodetector 1F has substantially the same configuration as the photodetector 1 of the above embodiment.

[0094] As described above, in the photodetector 1F of this modification, the second electrode 12 and the hole transport layer 14 are provided for each unit pixel P, similar to the first electrode 11 and the electron transport layer 13. This allows not only electrons but also holes collected from the second electrode 12 to be used as signal charges, thereby increasing the S / N ratio. Therefore, in addition to the effects of the above embodiment, it is possible to improve the device characteristics.

[0095] 21 shows an example in which adjacent unit pixels P are completely separated by the insulating film 151, but the present invention is not limited to this. In the photodetector 1F of this modified example, the photoelectric conversion layer 16 may extend across multiple unit pixels P as long as the second electrode 12 and the hole transport layer 14 are electrically separated for each unit pixel P, as shown in FIG.

[0096] (2-7. Modification 7) Fig. 24 is a schematic diagram showing an example of a cross-sectional configuration of a photodetector (photodetector 1G) according to Modification 7 of the present disclosure. Fig. 25 is a schematic diagram showing an example of a planar layout of the electron transport layer 13 and the hole transport layer 14 in a unit pixel P of the photodetector 1G shown in Fig. 24, and Fig. 24 shows a cross section corresponding to line VIII-VIII' shown in Fig. 25. The photodetector 1G is suitably used as a CMOS image sensor or the like for use in electronic devices such as digital still cameras and video cameras.

[0097] In the above-described modification 6, an example was shown in which adjacent unit pixels P are separated by an insulating film 151, and the second electrode 12 and the hole transport layer 14 are provided so as to surround the periphery of the first electrode 11 and the electron transport layer 13 provided approximately in the center of the unit pixel P, but the present invention is not limited to this. In the photodetector 1G of this modification, for example, the second electrode 12 and the hole transport layer 14 are provided so as to surround three sides of the rectangular first electrode 11 and electron transport layer 13. Except for this point, the photodetector 1G has substantially the same configuration as the photodetector 1 of the above-described embodiment.

[0098] In this manner, in the photodetector 1G of this modified example, the second electrode 12 and the hole transport layer 14 are provided so as to surround three sides of the rectangular first electrode 11 and the electron transport layer 13. Even with this configuration, the photodetector 1G of this modified example can achieve the same effects as those of the above embodiment.

[0099] 26 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector according to Modification 8 of the present disclosure (photodetector 1H). The photodetector 1H is suitable for use as a CMOS image sensor or the like used in electronic devices such as digital still cameras and video cameras.

[0100] In the above embodiment, an example has been shown in which the photoelectric conversion layer 16 is formed on the electron transport layer 13 and the hole transport layer 14 so that light incident on the on-chip lens 18 is incident directly on the photoelectric conversion layer 16 without passing through other members constituting the photoelectric conversion unit 10, but the present invention is not limited to this. In the photodetector 1H of this modified example, the hole transport layer provided on the second electrode 12 is further extended in the XY plane direction on the light incident side S1 of the photoelectric conversion layer 16. Except for this point, the photodetector 1H has substantially the same configuration as the photodetector 1 of the above embodiment.

[0101] [Method of Manufacturing Photodetector] The photodetector 1H can be manufactured, for example, as follows: Figures 27A to 27G show an example of a manufacturing process for the photodetector 1H.

[0102] First, in the same manner as in the above embodiment, an insulating film 15 is formed on the interlayer insulating layer 28 including the first electrode 11 and the second electrode 12. Next, as shown in Fig. 27A , the insulating film 15 is processed by, for example, photolithography and etching to form an opening 15H above the first electrode 11, and the first electrode 11 is exposed at the bottom of the opening. Subsequently, as shown in Fig. 27B , a film to become the electron transport layer 13 is formed by, for example, sputtering or CVD, and then the electron transport layer 13 is formed on the first electrode 11 by, for example, photolithography and etching.

[0103] Next, as shown in Figure 27C, a photoelectric conversion layer 16 is formed on the electron transport layer 13 and the insulating film 15, for example, by spin coating. Subsequently, as shown in Figure 27D, the photoelectric conversion layer 16 is processed, for example, by photolithography and etching, to form an opening 16H above the second electrode 12. Next, as shown in Figure 27E, the insulating film 15 exposed in the opening 16H is removed, for example, by photolithography and etching, to expose the second electrode 12 on the bottom surface of the opening 16H, and then a film that will become the hole transport layer 14 is formed, for example, by sputtering or CVD. The surface of the hole transport layer 14 is then planarized, for example, by chemical mechanical polishing (CMP).

[0104] 27F, a protective layer 17 is formed on the hole transport layer 14 by, for example, a CVD method. Finally, as shown in Fig. 27G, an on-chip lens 18 is disposed on the protective layer 17. In this manner, the photodetector 1H shown in Fig. 26 is completed.

[0105] In this manner, in the photodetector 1H of this modified example, the hole transport layer 14, which is provided on the second electrode 12 and arranged in parallel with the electron transport layer 13 in the XY plane direction, further extends in the XY plane direction on the light incident side S1 of the photoelectric conversion layer 16. Even with this configuration, the photodetector 1H of this modified example can achieve the same effects as those of the above embodiment.

[0106] 26 shows an example in which the hole transport layer 14 extends over the entire light incident side S1 of the photoelectric conversion layer 16, but the present disclosure is not limited thereto. FIG. 28 schematically illustrates another example (photodetector 1I) of the cross-sectional configuration of a photodetector according to Modification 8 of the present disclosure. The photodetector 1I is a combination of Modification 7 and this modification. For example, a portion of the hole transport layer 14 surrounding three sides of the rectangular electron transport layer 13 extends to the light incident side of the photoelectric conversion layer 16. Even with this configuration, the photodetector 1I of this modification is slightly inferior to the photodetector 1 of the above embodiment in terms of quantum efficiency improvement due to the hole transport layer 14 being stacked on the photoelectric conversion layer 16, but other effects similar to those of the above embodiment can be obtained.

[0107] In addition, when the hole transport layer 14 is partially extended to the light incident side of the photoelectric conversion layer 16 as in the photodetector 1I, for example, as shown in FIG. 29, the on-chip lens 18 may be shifted in a predetermined direction so that the focal position of the on-chip lens 18 and the position where the strongest internal electric field is formed in the unit pixel P (for example, the star mark in the figure) approximately coincide with each other.

[0108] 30 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector (photodetector 1J) according to a ninth modification of the present disclosure. The photodetector 1J is suitable for use as a CMOS image sensor or the like used in electronic devices such as digital still cameras and video cameras.

[0109] In the photodetector 1 and the like according to the above-described embodiment, the first electrode 11 and the second electrode 12 are arranged parallel to each other in the XY plane, and their upper surfaces are at the same height. Furthermore, in the photodetector 1 and the like, the hole transport layer 14 is formed thicker than the electron transport layer 13, so that the surface 14S1 of the hole transport layer 14 is positioned closer to the light incident side S1 than the surface 13S1 of the electron transport layer 13. However, this is not limiting. In the photodetector 1J of this modified example, the second electrode 12 is formed thicker than the first electrode 11, so that the surface 14S1 of the hole transport layer 14 is positioned closer to the light incident side S1 than the surface 13S1 of the electron transport layer 13. Except for this point, the photodetector 1J has substantially the same configuration as the photodetector 1 according to the above-described embodiment.

[0110] In this way, in the photodetector 1J of this modified example, the second electrode 12 is formed to be thicker than the first electrode 11, so that the surface 14S1 of the hole transport layer 14 is located closer to the light incident side S1 than the surface 13S1 of the electron transport layer 13. Even with this configuration, the photodetector 1J of this modified example can achieve the same effects as those of the above embodiment.

[0111] That is, the two-dimensional or three-dimensional internal electric field generated in the photoelectric conversion layer 16 described above is not limited to the film thicknesses of the electron transport layer 13 and the hole transport layer 14, as long as the surface 14S1 of the hole transport layer 14 is formed at a position higher than the surface 13S1 of the electron transport layer 13. This allows the charge carriers (electrons and holes) generated in the photoelectric conversion layer 16 to be transported to the corresponding electrodes.

[0112] (2-10. Modification 10) Fig. 31 is a schematic diagram showing an example of a cross-sectional configuration of a photodetector according to Modification 10 of the present disclosure (photodetector 1K). Fig. 32 is a schematic diagram showing another example of a cross-sectional configuration of a photodetector according to Modification 10 of the present disclosure (photodetector 1L). The photodetectors 1K and 1L are suitable for use as CMOS image sensors used in electronic devices such as digital still cameras and video cameras.

[0113] In the photodetector 1 and other embodiments described above, an electron transport layer 13 is provided on the first electrode 11, a hole transport layer 14 is provided on the second electrode 12, and the surface 14S1 of the hole transport layer 14 is located closer to the light incident side S1 than the surface 13S1 of the electron transport layer 13. However, this is not limiting. In a photodetector 1K of this modified example, the second electrode 12 also serves as the hole transport layer 14. In the photodetector 1K, a portion of the second electrode 12 protrudes into the photoelectric conversion layer 16, and the upper surface (surface 12S1) of the second electrode 12 is located closer to the light incident side S1 than the electron transport layer 13. In the photodetector 1L, the first electrode 11 also serves as the electron transport layer 13. In the photodetector 1L, the first electrode 11 is in direct contact with the photoelectric conversion layer 16, and the upper surface (surface 11S1) of the first electrode 11 is formed at a lower position than the surface 14S1 of the hole transport layer 14. Except for this point, the photodetectors 1K and 1L have substantially the same configuration as the photodetector 1 of the above embodiment.

[0114] As described above, in the photodetector 1K of this modified example, the second electrode 12 is formed as a thick film and protrudes into the photoelectric conversion layer 16 to serve as a hole transport layer. In the photodetector 1L of this modified example, the first electrode 11 and the photoelectric conversion layer 16 are in direct contact with each other to serve as an electron transport layer. As described above, the present technology can also be applied to a Schottky junction system in which the first electrode 11 or the second electrode 12 is bonded to the photoelectric conversion layer 16. Even with such a configuration, the photodetectors 1K and 1L of this modified example can achieve the same effects as those of the above-described embodiment.

[0115] 3. Application Examples (Application Example 1) Furthermore, the above-described photodetector (for example, photodetector 1) can be applied to various electronic devices, such as imaging systems such as digital still cameras and digital video cameras, mobile phones with an imaging function, or other devices with an imaging function.

[0116] FIG. 33 is a block diagram showing an example of the configuration of electronic device 1000.

[0117] As shown in Figure 33, the electronic device 1000 includes an optical system 1001, a photodetector 1, and a DSP (Digital Signal Processor) 1002, and is configured by connecting the DSP 1002, memory 1003, display device 1004, recording device 1005, operation system 1006, and power supply system 1007 via a bus 1008, and is capable of capturing still images and moving images.

[0118] The optical system 1001 is configured to have one or more lenses, and receives incident light (image light) from a subject and forms an image on the imaging surface of the photodetector 1 .

[0119] The above-described photodetector 1 is applied as the photodetector 1. The photodetector 1 converts the amount of incident light imaged on the imaging surface by the optical system 1001 into an electrical signal on a pixel-by-pixel basis and supplies the signal to the DSP 1002 as a pixel signal.

[0120] The DSP 1002 performs various signal processing on the signal from the photodetector 1 to acquire an image, and temporarily stores the image data in the memory 1003. The image data stored in the memory 1003 is recorded in the recording device 1005 or supplied to the display device 1004 to display the image. In addition, the operation system 1006 accepts various operations by the user and supplies operation signals to each block of the electronic device 1000, and the power supply system 1007 supplies the power necessary to drive each block of the electronic device 1000.

[0121] (Application Example 2) Fig. 34A schematically illustrates an example of the overall configuration of a light detection system 2000 including the light detection device 1. Fig. 34B illustrates an example of the circuit configuration of the light detection system 2000. The light detection system 2000 includes a light emitting device 2001 serving as a light source unit that emits infrared light L2, and a light detection device 2002 serving as a light receiving unit having a photoelectric conversion element. The light detection device 1 described above can be used as the light detection device 2002. The light detection system 2000 may further include a system control unit 2003, a light source driving unit 2004, a sensor control unit 2005, a light source side optical system 2006, and a camera side optical system 2007.

[0122] The photodetector 2002 can detect light L1 and light L2. Light L1 is external ambient light reflected by the object (measurement target) 2100 ( FIG. 34A ). Light L2 is light emitted by the light-emitting device 2001 and then reflected by the object 2100. Light L1 is, for example, visible light, and light L2 is, for example, infrared light. Light L1 can be detected by a photoelectric conversion unit in the photodetector 2002, and light L2 can be detected by a photoelectric conversion region in the photodetector 2002. Image information of the object 2100 can be obtained from light L1, and distance information between the object 2100 and the photodetector system 2000 can be obtained from light L2. The photodetector system 2000 can be mounted, for example, on an electronic device such as a smartphone or a mobile object such as a car. The light-emitting device 2001 can be configured, for example, by a semiconductor laser, a surface-emitting semiconductor laser, or a vertical-cavity surface-emitting laser (VCSEL). The method of detecting the light L2 emitted from the light-emitting device 2001 by the photodetector 2002 can be, for example, an iTOF method, but is not limited to this. In the iTOF method, the photoelectric conversion unit can measure the distance to the subject 2100, for example, by using the time-of-flight (TOF) of light. The method of detecting the light L2 emitted from the light-emitting device 2001 by the photodetector 2002 can also be, for example, a structured light method or a stereo vision method. For example, in the structured light method, a predetermined pattern of light is projected onto the subject 2100, and the distance between the photodetector system 2000 and the subject 2100 can be measured by analyzing the distortion of the pattern. In addition, in the stereo vision method, for example, two or more cameras are used to acquire two or more images of the subject 2100 viewed from two or more different viewpoints, thereby measuring the distance between the photodetector system 2000 and the subject. The light emitting device 2001 and the light detecting device 2002 can be controlled synchronously by a system control unit 2003 .

[0123] 14. Application Example Application Example to Endoscopic Surgery System The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0124] FIG. 35 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0125] 35 shows an operator (doctor) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0126] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the example shown, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible scope having a flexible lens barrel.

[0127] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0128] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected onto 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 the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0129] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls 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 image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0130] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0131] The light source device 11203 is composed of a light source such as an LED (light emitting diode), and supplies irradiation light to the endoscope 11100 when photographing the surgical area, etc.

[0132] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) of the endoscope 11100.

[0133] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 inflates the body cavity of the patient 11132 through the insufflation tube 11111 in order to ensure a clear field of view for the endoscope 11100 and a working space for the surgeon. The recorder 11207 is a device capable of recording various types of information related to the surgery. The printer 11208 is a device capable of printing various types of information related to the surgery in various formats such as text, images, or graphs.

[0134] The light source device 11203, which supplies illumination light to the endoscope 11100 when photographing the surgical site, can be configured from a white light source, such as an LED, a laser light source, or a combination of these. When the white light source is configured from a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, allowing the light source device 11203 to adjust the white balance of the captured image. In this case, it is also possible to time-share images corresponding to each RGB by irradiating the object of observation with laser light from each RGB laser light source and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, color images can be obtained without providing a color filter to the image sensor.

[0135] Furthermore, the light source device 11203 may be controlled to change the intensity of light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and combining the images, it is possible to generate an image with a high dynamic range that is free from so-called blocked-up shadows and blown-out highlights.

[0136] The light source device 11203 may also be configured to supply light in a predetermined wavelength range compatible with special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light with a narrower band than the light irradiated during normal observation (i.e., white light), thereby capturing high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, known as narrow-band imaging. Alternatively, special light observation may involve fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation can involve irradiating excitation light onto body tissues and observing the fluorescence from the tissues (autofluorescence observation), or by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the 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 compatible with such special light observation.

[0137] FIG. 36 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0138] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other via a transmission cable 11400 so that they can communicate with each other.

[0139] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses including a zoom lens and a focus lens.

[0140] The imaging unit 11402 may include one imaging element (a so-called single-chip type) or multiple imaging elements (a so-called multi-chip type). When the imaging unit 11402 is configured as a multi-chip 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 these 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. The 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. Note that when the imaging unit 11402 is configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0141] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately after the objective lens.

[0142] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be adjusted appropriately.

[0143] The communication unit 11404 is configured by a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0144] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201 and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of imaging, and / or information specifying the magnification and focus of the captured image.

[0145] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0146] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404 .

[0147] The communication unit 11411 is configured by a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0148] Furthermore, the communication unit 11411 transmits to the camera head 11102 a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0149] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0150] The control unit 11413 performs various controls related to the imaging of the surgical site, etc. by the endoscope 11100 and the display of the captured image obtained by imaging the surgical site, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0151] Furthermore, the control unit 11413 displays the captured image showing the surgical site, etc., on the display device 11202 based on the image signal subjected to image processing 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 technologies. For example, the control unit 11413 can recognize surgical tools such as forceps, specific biological parts, bleeding, mist generated when using the energy treatment tool 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition results to superimpose various surgical support information on the image of the surgical site. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0152] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for electrical signal communication, an optical fiber for optical communication, or a composite cable of these.

[0153] In the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0154] The above describes an example of an endoscopic surgery system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the imaging unit 11402 among the components described above. By applying the technology according to the present disclosure to the imaging unit 11402, detection accuracy is improved.

[0155] Although an endoscopic surgery system has been described as an example here, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0156] (Application Example to Mobile Object) 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 mobile object, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, a robot, construction machinery, or agricultural machinery (tractor).

[0157] FIG. 37 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

[0158] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 37, 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 shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053.

[0159] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0160] The body system control unit 12020 controls the operation of various devices equipped in 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 headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0161] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, characters on the road surface, etc. based on the received images.

[0162] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0163] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0164] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands 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 distance between vehicles, maintaining vehicle speed, vehicle collision warning, vehicle lane departure warning, etc.

[0165] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0166] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside 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 information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0167] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying information to vehicle occupants or the outside of the vehicle. In the example of Fig. 37, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0168] FIG. 38 is a diagram showing an example of the installation position of the imaging unit 12031.

[0169] In FIG. 38, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0170] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided on the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0171] 38 shows an example of the imaging ranges of the imaging units 12101 to 12104. 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 imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.

[0172] At least one of the image capturing units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the image capturing units 12101 to 12104 may be a stereo camera made up of multiple image capturing elements, or may be an image capturing element having pixels for phase difference detection.

[0173] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0174] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding 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. The microcomputer 12051 then determines a collision risk that indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0175] At least one of the image capturing 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 a pedestrian is present in the images captured by the image capturing units 12101 to 12104. Such pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104 as infrared cameras and performing pattern matching on a series of feature points that indicate the outline of an object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0176] The foregoing has described an example of a mobile object control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the image capture unit 12031 of the above-described configuration. Specifically, the photodetection devices according to the above-described embodiments and their modifications (e.g., photodetection device 1) can be applied to the image capture unit 12031. By applying the technology according to the present disclosure to the image capture unit 12031, it is possible to obtain high-resolution captured images with little noise, thereby enabling high-precision control using the captured images in the mobile object control system.

[0177] Although the present disclosure has been described above by giving the embodiment, modifications 1 to 8, and application examples, the present technology is not limited to the above-described embodiment, etc., and various modifications are possible. For example, the above-described modifications 1 to 8 can be appropriately combined with other embodiment and modifications.

[0178] In the above-described embodiments, the first electrode 11 and the electron transport layer 13, and the second electrode 12 and the hole transport layer 14 are formed in approximately the same layout, but this is not limiting. For example, in the embodiments, the second electrode 12 does not necessarily have to be formed continuously so as to surround the first electrode 11, and may be formed, for example, at an intersection of the row direction (e.g., the X-axis direction) and the column direction (e.g., the Y-axis direction), in other words, at the four corners of a unit pixel P having an approximately square shape.

[0179] Furthermore, while the above-described embodiments and the like have shown examples in which electrons are used as signal charges, the present invention is not limited thereto, and holes may also be used as signal charges. In this case, in the photodetector device, for example, the second electrode 12 and the hole transport layer 14 are provided approximately at the center of the unit pixel P, and the first electrode 11 and the electron transport layer 13 are provided between adjacent unit pixels P, for example, so as to surround the second electrode 12. A surface 13S1 on the light incident side S1 of the electron transport layer 13 is formed closer to the light incident side S1 than a surface 14S1 on the light incident side S1 of the hole transport layer 14.

[0180] The effects described in this specification are merely examples and are not limited to those described, and other effects may also be obtained.

[0181] The present disclosure may also be configured as follows. According to the present technology having the following configuration, a first electrode and a second electrode are disposed at a distance from each other on the side opposite the light incident side of a photoelectric conversion layer, and a first charge transport layer and a second charge transport layer are disposed above the first electrode and the second electrode, respectively. This increases the amount of light incident on the photoelectric conversion layer compared to a photodetector in which the first electrode, the first charge transport layer, the photoelectric conversion layer, the second charge transport layer, and the second electrode are stacked in this order in the light incident surface direction. This makes it possible to improve quantum efficiency. (1) A photodetector comprising: a photoelectric conversion layer; a first electrode disposed at a side opposite the light incident side of the photoelectric conversion layer; a second electrode disposed at a distance from the first electrode on the side opposite the light incident side of the photoelectric conversion layer; a first charge transport layer disposed above the first electrode and having a first surface on the light incident side; and a second charge transport layer disposed above the second electrode and having a second surface closer to the light incident side than the first surface. (2) The photodetector according to (1), wherein the first electrode and the second electrode are arranged in parallel in an in-plane direction in which the photoelectric conversion layer extends, and the second charge transport layer has a thickness greater than that of the second charge transport layer and a portion thereof protrudes into the photoelectric conversion layer. (3) The photodetector according to (1) or (2), further comprising an insulating film arranged between the first charge transport layer and the second charge transport layer and electrically separating the first charge transport layer from the second charge transport layer. (4) The photodetector according to any one of (1) to (3), wherein the second surface of the second charge transport layer is flush with the light-incident surface of the photoelectric conversion layer. (5) The photodetector according to any one of (1) to (4), wherein the second charge transport layer has the second surface within the photoelectric conversion layer. (6) The photodetector according to any one of (1) to (5), further comprising a pixel section in which a plurality of pixels are arranged two-dimensionally in an array, wherein a first charge transport section consisting of the first electrode and the first charge transport layer is arranged in each of the plurality of pixels, and a second charge transport section consisting of the second electrode and the second charge transport layer is arranged between adjacent pixels.(7) The photodetector according to any one of (1) to (6), further comprising a pixel section in which a plurality of pixels are arranged two-dimensionally in an array, wherein a first charge transport section formed by the first electrode and the first charge transport layer and a second charge transport section formed by the second electrode and the second charge transport layer are repeatedly and periodically arranged from approximately the center of the pixel toward the periphery. (8) The photodetector according to (7), further comprising a pixel section in which a plurality of pixels are arranged two-dimensionally in an array, wherein each of the plurality of pixels has a plurality of first charge transport sections formed by the first electrode and the first charge transport layer and one second charge transport section formed by the second electrode and the second charge transport layer, and the plurality of first charge transport sections are electrically separated by an insulating film. (10) The photodetector according to any one of (1) to (9), further comprising a pixel section in which a plurality of pixels are two-dimensionally arranged in an array, wherein each of the plurality of pixels has a plurality of first charge transport sections formed by the first electrode and the first charge transport layer, and one second charge transport section formed by the second electrode and the second charge transport layer, and the plurality of first charge transport sections are electrically isolated by an insulating film and the second charge transport section. (11) The photodetector according to (10), wherein signal charges are read out separately from each of the plurality of first charge transport sections. (12) The photodetector according to (10), wherein the plurality of pixels include a first pixel in which the plurality of first charge transport sections are arranged in a first direction, and a second pixel in which the plurality of first charge transport sections are arranged in a second direction perpendicular to the first direction. (13) The photodetector according to any one of (1) to (12), further comprising a functional layer between the photoelectric conversion layer and the first charge transport layer and / or between the photoelectric conversion layer and the second charge transport layer.(14) The photodetector according to any one of (1) to (13), further comprising a pixel section in which a plurality of pixels are two-dimensionally arranged in an array, wherein a first charge transport section consisting of the first electrode and the first charge transport layer is disposed approximately at the center of each of the plurality of pixels, a second charge transport section consisting of the second electrode and the second charge transport layer is disposed at the periphery of each of the plurality of pixels, and an insulating film is disposed between adjacent pixels. (15) The photodetector according to (14), wherein the insulating film penetrates the photoelectric conversion layer in a thickness direction. (16) The photodetector according to (14), wherein the insulating film has an upper surface within the photoelectric conversion layer. (17) The photodetector according to any one of (1) to (16), wherein the second charge transport layer further extends over at least a portion of the light incident side of the photoelectric conversion layer. (18) The photodetector according to (17), further comprising a pixel section in which a plurality of pixels are two-dimensionally arranged in an array, and the second charge transport layer extends across the plurality of pixels on the light incident side of the photoelectric conversion layer. (19) The photodetector according to any one of (1) to (18), wherein one of the first electrode and the second electrode also serves as the first charge transport layer and the second charge transport layer provided above the electrode. (20) The photodetector according to any one of (1) to (19), further comprising a pixel section in which a plurality of pixels are two-dimensionally arranged in an array, and a microlens disposed in each of the plurality of pixels on the light incident side surface of the photoelectric conversion layer, wherein the focal position of the microlens substantially coincides with the position where the largest electric field is applied between the first charge transport layer and the second charge transport layer. (21) The photodetector according to any one of (1) to (20), wherein the photoelectric conversion layer includes quantum dots, an organic compound semiconductor, or an organic-inorganic perovskite.(22) An electronic device comprising a photodetector, the photodetector comprising: a photoelectric conversion layer; a first electrode arranged on the opposite side of the photoelectric conversion layer from the light incident side; a second electrode arranged on the opposite side of the photoelectric conversion layer from the light incident side and spaced apart from the first electrode; a first charge transport layer provided above the first electrode and having a first surface on the light incident side; and a second charge transport layer provided above the second electrode and having a second surface closer to the light incident side than the first surface.

Claims

1. A photodetector comprising: a photoelectric conversion layer; a first electrode arranged on the side opposite to the light incident side of the photoelectric conversion layer; a second electrode arranged on the side opposite to the light incident side of the photoelectric conversion layer and spaced apart from the first electrode; a first charge transport layer provided above the first electrode and having a first surface on the light incident side; and a second charge transport layer provided above the second electrode and having a second surface closer to the light incident side than the first surface.

2. The photodetector device according to claim 1, wherein the first electrode and the second electrode are arranged in parallel in the in-plane direction in which the photoelectric conversion layer extends, and the second charge transport layer has a thickness greater than that of the first charge transport layer, and a portion of the second charge transport layer protrudes into the photoelectric conversion layer.

3. The photodetector device of claim 1, further comprising an insulating film disposed between the first charge transport layer and the second charge transport layer, electrically isolating the first charge transport layer and the second charge transport layer.

4. The photodetector according to claim 1, wherein the second surface of the second charge transport layer is flush with the light incident surface of the photoelectric conversion layer.

5. The photodetector device according to claim 1, wherein the second charge transport layer has the second surface within the photoelectric conversion layer.

6. The photodetector according to claim 1, further comprising a pixel section in which a plurality of pixels are arranged two-dimensionally in an array, wherein a first charge transport section consisting of the first electrode and the first charge transport layer is arranged in each of the plurality of pixels, and a second charge transport section consisting of the second electrode and the second charge transport layer is arranged between adjacent pixels.

7. The photodetector according to claim 1, further comprising a pixel section in which a plurality of pixels are arranged two-dimensionally in an array, wherein a first charge transport section consisting of the first electrode and the first charge transport layer and a second charge transport section consisting of the second electrode and the second charge transport layer are repeatedly and periodically arranged from approximately the center of the pixel toward the periphery.

8. The photodetector according to claim 7, wherein the plurality of first charge transporting portions and the plurality of second charge transporting portions arranged in a repeated, periodic manner are electrically connected to each other.

9. The photodetector according to claim 1, further comprising a pixel section in which a plurality of pixels are arranged two-dimensionally in an array, each of the plurality of pixels having a plurality of first charge transport sections formed from the first electrode and the first charge transport layer, and one second charge transport section formed from the second electrode and the second charge transport layer, and the plurality of first charge transport sections being electrically separated by an insulating film.

10. The photodetector device of claim 1, further comprising a pixel section in which a plurality of pixels are arranged two-dimensionally in an array, each of the plurality of pixels having a plurality of first charge transport sections formed from the first electrode and the first charge transport layer, and one second charge transport section formed from the second electrode and the second charge transport layer, and the plurality of first charge transport sections being electrically isolated by an insulating film and the second charge transport section.

11. The photodetector according to claim 10, wherein the signal charges of the plurality of first charge transporting parts are read out separately from each other.

12. The photodetection device of claim 10, wherein the plurality of pixels includes a first pixel in which the plurality of first charge transport regions are arranged in a first direction, and a second pixel in which the plurality of first charge transport regions are arranged in a second direction perpendicular to the first direction.

13. The photodetector device according to claim 1, further comprising a functional layer between the photoelectric conversion layer and the first charge transport layer and / or between the photoelectric conversion layer and the second charge transport layer.

14. The photodetector according to claim 1, further comprising a pixel section in which a plurality of pixels are arranged two-dimensionally in an array, wherein a first charge transport section consisting of the first electrode and the first charge transport layer is arranged approximately in the center of each of the plurality of pixels, a second charge transport section consisting of the second electrode and the second charge transport layer is arranged in the periphery of each of the plurality of pixels, and an insulating film is arranged between adjacent pixels.

15. The photodetector according to claim 1, wherein the second charge transport layer further extends over at least a portion of the light incident side of the photoelectric conversion layer.

16. The photodetector according to claim 15, further comprising a pixel section in which a plurality of pixels are arranged two-dimensionally in an array, and the second charge transport layer extends across the plurality of pixels on the light incident side of the photoelectric conversion layer.

17. The photodetector device according to claim 1, wherein one of the first electrode and the second electrode also serves as the first charge transport layer and the second charge transport layer provided above it, respectively.

18. The photodetector device according to claim 1, further comprising: a pixel section in which a plurality of pixels are arranged two-dimensionally in an array; and a microlens arranged in each of the plurality of pixels on the light incident surface of the photoelectric conversion layer, the focal position of the microlens substantially coinciding with the position at which the largest electric field is applied between the first charge transport layer and the second charge transport layer.

19. The photodetector device according to claim 1, wherein the photoelectric conversion layer comprises quantum dots, an organic compound semiconductor, or an organic-inorganic perovskite.

20. An electronic device comprising a photodetector, the photodetector comprising: a photoelectric conversion layer; a first electrode arranged on the side opposite to the light incident side of the photoelectric conversion layer; a second electrode arranged on the side opposite to the light incident side of the photoelectric conversion layer and spaced apart from the first electrode; a first charge transport layer provided above the first electrode and having a first surface on the light incident side; and a second charge transport layer provided above the second electrode and having a second surface closer to the light incident side than the first surface.

Images