WO2023276274A1

WO2023276274A1 - Photoelectric conversion element, light detecting device, and electronic apparatus

Info

Publication number: WO2023276274A1
Application number: PCT/JP2022/008881
Authority: WO
Inventors: 修一瀧澤; 陽介齊藤; 修榎; 治典塩見; 加代子菊地
Original assignee: ソニーセミコンダクタソリューションズ株式会社; ソニーグループ株式会社
Priority date: 2021-06-29
Filing date: 2022-03-02
Publication date: 2023-01-05
Also published as: JP2023005880A

Abstract

Provided is a photoelectric conversion element having high functionality. The disclosed photoelectric conversion element includes a first electrode (5), a second electrode (3), a photoelectric conversion layer (4), and a reflective layer (2). The first electrode (5) transmits light in a first wavelength region. The second electrode (3) faces the first electrode (5), and transmits light in the first wavelength region. The photoelectric conversion layer (4) is positioned between the first electrode (5) and the second electrode (3), and detects and photoelectrically converts light in the first wavelength region. The reflective layer (2) is positioned on the opposite side to the photoelectric conversion layer (4), as seen from the second electrode (3), and reflects, toward the photoelectric conversion layer (4), light in the first wavelength region that has been transmitted through the first electrode (5), the photoelectric conversion layer (4), and the second electrode (3).

Description

Photoelectric conversion element, photodetector, and electronic device

The present disclosure relates to a photoelectric conversion element that performs photoelectric conversion, and a photodetector and electronic equipment having the same.

So far, a photoelectric conversion element including a photoelectric conversion layer that performs photoelectric conversion by receiving visible light or the like, and a solid-state imaging device including the same have been proposed (see, for example, Patent Document 1).

JP 2018-98438 A

By the way, solid-state imaging devices are required to improve their functions.

Therefore, it is desirable to provide photoelectric conversion elements with high functionality.

A photoelectric conversion element as one embodiment of the present disclosure includes a laminated structure having a first electrode, a second electrode, a photoelectric conversion layer, and a reflective layer. The first electrode transmits light in the first wavelength band. The second electrode faces the first electrode and transmits light in the first wavelength band. The photoelectric conversion layer is located between the first electrode and the second electrode, and detects light in the first wavelength band to perform photoelectric conversion. The reflective layer is located on the opposite side of the photoelectric conversion layer when viewed from the second electrode, and reflects light in the first wavelength band that passes through the first electrode, the photoelectric conversion layer, and the second electrode toward the photoelectric conversion layer. do.

1 is a cross-sectional schematic diagram showing an example of an imaging device according to a first embodiment of the present disclosure; FIG. It is a cross-sectional schematic diagram showing the imaging element as a 1st modification of the 1st Embodiment of this indication. It is a cross-sectional schematic diagram showing the imaging element as a 2nd modification of 1st Embodiment of this indication. FIG. 20 is a schematic cross-sectional view showing an imaging device as a twenty-third modification of the first embodiment of the present disclosure; FIG. 2 is a schematic configuration diagram representing an imaging device according to a second embodiment of the present disclosure; FIG. 1 is a schematic diagram showing an example of the overall configuration of an electronic device; FIG. 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; FIG. FIG. 4 is an explanatory diagram showing an example of installation positions of an outside information detection unit and an imaging unit; 1 is a diagram showing an example of a schematic configuration of an endoscopic surgery system; FIG. 3 is a block diagram showing an example of functional configurations of a camera head and a CCU; FIG. It is a figure showing the evaluation result of an experimental example. FIG. 4 is a first characteristic diagram showing wavelength dependence of reflectance of a conductive film; FIG. 4 is a second characteristic diagram showing the wavelength dependence of the reflectance of a conductive film; It is a cross-sectional schematic diagram showing an example of an imaging device as another modified example of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order.
1. First Embodiment An example of an imaging device having a reflective layer in contact with a lower electrode.
2. Modification of First Embodiment 2-1. An example of an imaging device further provided with an insulating layer between a lower electrode and a reflective layer.
2-2. An example of an imaging device further provided with a second photoelectric conversion layer.
2-3. An example of an imaging device provided with a curved reflective layer.
3. Second Embodiment An example of an imaging device having a plurality of imaging elements.
4. Example of application to electronic equipment5. Example of application to moving bodies6. Application example to endoscopic surgery system7. Experimental example 8. Other variations

<1. First Embodiment>
[Configuration of image sensor P1]
FIG. 1 is a cross-sectional view schematically showing an imaging device P1 according to the first embodiment of the present disclosure. The imaging element P1 is a specific example corresponding to the "photoelectric conversion element" of the present disclosure. The imaging element P1 includes a laminated structure having a substrate 1, a reflective layer 2, a lower electrode 3, a photoelectric conversion layer 4, and an upper electrode 5 in this order, as shown in FIG. 1, for example. A buffer layer 6 may further be provided between the lower electrode 3 and the photoelectric conversion layer 4 . A buffer layer 7 may further be provided between the photoelectric conversion layer 4 and the upper electrode 5 . The imaging device P1 may further have a contact layer 8 provided to penetrate the insulating layer Z. As shown in FIG. The insulating layer Z is provided on the same layer as the reflective layer 2 . The contact layer 8 includes, for example, an upper end connected to the lower surface of the lower electrode 3 and a lower end connected to the upper surface of the wiring layer M provided on the substrate 1 .

Here, the upper electrode 5 is a specific example corresponding to the "first electrode" of the present disclosure. The lower electrode 3 is a specific example corresponding to the "second electrode" of the present disclosure. The photoelectric conversion layer 4 is a specific example corresponding to the "photoelectric conversion layer" of the present disclosure. The reflective layer 2 is a specific example corresponding to the "reflective layer" of the present disclosure.

In the imaging device P1, light incident from the side opposite to the substrate 1 when viewed from the upper electrode 5 reaches the photoelectric conversion layer 4, and charges corresponding to the incident light are generated in the photoelectric conversion layer 4. . Further, in the imaging element P1, a predetermined bias voltage is applied between the lower electrode 3 and the upper electrode 5, thereby causing the charge generated in the photoelectric conversion layer 4 to move to the lower electrode 3, and then move to the lower electrode 3. A signal corresponding to the charge can be taken out to the outside. Note that the imaging element P1 can be formed by, for example, a vacuum deposition method, or can be formed by a vacuum sputtering method. Alternatively, the imaging element P1 can also be formed using a coating method.

The substrate 1 is, for example, a supporting substrate made of quartz.

The reflective layer 2 contains, for example, metal as a main component. Metals contained as a main component in the reflective layer 2 include, for example, aluminum (Al), Cu (copper), Ag (silver), and Au (gold). The thickness of the reflective layer 2 can be, for example, 50 nm or more and 100 nm or less. Further, in the imaging device P1, the lower electrode 3 and the reflective layer 2 are configured to be in direct contact with each other.

The lower electrode 3 and the upper electrode 5 are each conductive. Moreover, the lower electrode 3 and the upper electrode 5 are each configured to be able to transmit at least the light in the first wavelength band received by the photoelectric conversion layer 4 . The first wavelength range is, for example, a visible range, a near-infrared range, or an infrared range. That is, the lower electrode 3 and the upper electrode 5 can be made of, for example, a transparent conductive material. As used herein, the term “transparent conductive material” means a material that exhibits a transmittance higher than that of the reflective layer 2 with respect to light incident on the photoelectric conversion layer 4 . The transparent conductive material desirably has, for example, a transmittance of 90% or more for visible light or infrared light. Specifically, transparent conductive materials include indium oxide, indium tin oxide (ITO), indium-zinc oxide (IZO), indium-gallium oxide (IGO), indium-gallium-zinc oxide (IGZO, In _-GaZnO4 ), IFO (fluorinated indium oxide), tin oxide (SnO2), ATO (Sb _- doped SnO2), FTO (fluorinated tin oxide), zinc oxide, aluminum-zinc oxide (AZO), Gallium-zinc oxide (GZO), boron-zinc oxide, titanium oxide (TiO ₂ ), niobium-titanium oxide (TNO), antimony oxide, spinel-type oxides, oxides having a YbFe ₂ O ₄ structure. be able to. Further examples include transparent electrodes having gallium oxide, titanium oxide, niobium oxide, nickel oxide, or the like as a base layer. The thickness of the lower electrode 3 and the thickness of the upper electrode 5 can each be, for example, 50 nm or more and 100 nm or less. In particular, for the lower electrode 3, the thickness of the lower electrode 3 is d, the wavelength of light transmitted through the lower electrode 3 is λ, and the refractive index of the lower electrode 3 with respect to light having a wavelength λ that is transmitted through the lower electrode 3 is n. At that time, it is desirable to satisfy the following formula (1).
d=λ/(4×n) (1)

The photoelectric conversion layer 4 is made of, for example, a photoelectric conversion material that absorbs light in the first wavelength band and generates charges according to the absorbed light. The photoelectric conversion layer 4 may have a single layer structure, or may have a multilayer structure. Both an inorganic material and an organic material can be used as the photoelectric conversion material forming the photoelectric conversion layer 4 . However, from the viewpoint of superior spectral characteristics and photosensitivity, it is preferable to use an organic material rather than an inorganic material. Examples of the organic material forming the photoelectric conversion layer 4 include quinacridone skeleton, phthalocyanine skeleton, and anthraquinone skeleton materials.

The buffer layer 6 can be made of, for example, titanium oxide or zinc oxide.

The buffer layer 7 can be made of poly(3-hexylthiophene-2,5-diyl), for example.

The contact layer 8 is a conductive path through which charges generated in the photoelectric conversion layer 4 are extracted to the wiring layer M through the lower electrode 3 . The contact layer 8 may be made of, for example, Cu (copper).

The insulating layer Z can be made of, for example, aluminum oxide (Al ₂ O ₃ ) or aluminum nitride (AlN).

The wiring layer M can be made of, for example, Cu (copper).

[Action and effect of image sensor P1]
As described above, the imaging device P1 of the present embodiment includes a laminated structure having the upper electrode 5, the photoelectric conversion layer 4, the lower electrode 3, and the reflective layer in this order. The photoelectric conversion layer 4 detects light in the first wavelength range, ie, visible light or infrared light, and performs photoelectric conversion. Both the upper electrode 5 and the lower electrode 3 transmit light in the first wavelength band. The reflective layer 2 is located on the opposite side of the photoelectric conversion layer 4 when viewed from the lower electrode 3 , and reflects light in the first wavelength band that passes through the upper electrode 5 , the photoelectric conversion layer 4 , and the lower electrode 3 to the photoelectric conversion layer 4 . It is designed to reflect toward.

Thus, in the imaging device P1, the reflective layer 2 is provided separately from the lower electrode 3, so the lower electrode 3 can be made of a material other than metal. If the lower electrode 3 is made of metal, an oxide film may form on the surface of the lower electrode 3 during the manufacturing process or under the environment of use. If such an oxide film is formed on the surface of the lower electrode 3, an increase in resistance between the lower electrode 3 and the upper electrode 5, a change in the work function of the lower electrode 3, and the like may occur. Moreover, when the lower electrode 3 is made of metal, the metal may be eluted into the buffer layer 6 . In such a case, there is concern about deterioration of photoelectric conversion characteristics. However, in the imaging device P1 of the present embodiment, the lower electrode 3 is made of a non-metallic transparent conductive material such as ITO. Elution of metal into the buffer layer 6 can be avoided. Therefore, the photoelectric conversion performance of the image sensor P1 can be stably obtained. That is, it is possible to suppress deterioration in performance due to the manufacturing process and usage environment, and obtain high long-term reliability.

Furthermore, in the imaging element P1, the reflective layer 2 exhibiting a high reflectance with respect to the light in the first wavelength band is provided on the opposite side of the photoelectric conversion layer 4 when viewed from the lower electrode 3. Therefore, even when the photoelectric conversion layer 4 is thinned, the optical path length can be lengthened, and a decrease in external quantum efficiency (EQE) can be suppressed. That is, a decrease in photoelectric conversion efficiency can be suppressed. In addition, by making the photoelectric conversion layer 4 thinner, it is possible to shorten the readout time of the charges generated in the photoelectric conversion layer 4 . That is, responsiveness can be improved. Therefore, it is possible to ensure both excellent external quantum efficiency (EQE) and excellent responsiveness.

Also, in the imaging device P1, the lower electrode 3 and the reflective layer 2 are in direct contact. Therefore, it is advantageous to reduce the thickness of the entire image sensor P1. Moreover, since the reflective layer 2 can be brought close to the photoelectric conversion layer 4 , it is advantageous for increasing the photoelectric conversion efficiency of the photoelectric conversion layer 4 .

<2. Modification of First Embodiment>
[First modification]
FIG. 2 is a cross-sectional view schematically showing an imaging device P2 as a first modification of the first embodiment of the present disclosure. The imaging element P2 is also a specific example corresponding to the "photoelectric conversion element" of the present disclosure.

The imaging device P2 further includes an insulating layer Z2 provided between the lower electrode 3 and the reflective layer 2, as shown in FIG. The insulating layer Z2 can be made of, for example, aluminum oxide (Al ₂ O ₃ ) or aluminum nitride (AlN). The configuration of the imaging device P2 is substantially the same as the configuration of the imaging device P1, except that an insulating layer Z2 is further provided.

Thus, the imaging element P2 further includes the insulating layer Z2 provided between the lower electrode 3 and the reflective layer 2. As shown in FIG. Therefore, for example, when the reflective layer 2 is made of metal, it is possible to reliably avoid the influence of the formation of an oxide film on the surface of the reflective layer 2 on the lower electrode 3, such as an increase in the resistance of the lower electrode 3. can.

[Second modification]
FIG. 3 is a cross-sectional view schematically showing an imaging device P3 as a second modification of the first embodiment of the present disclosure. The imaging element P3 is also a specific example corresponding to the "photoelectric conversion element" of the present disclosure.

The imaging device P3 further includes a semiconductor layer 9, an insulating layer Z3, and an insulating layer Z4, as shown in FIG. The semiconductor layer 9 is provided between the lower electrode 3 and the photoelectric conversion layer 4 . The insulating layer Z3 is provided between the semiconductor layer 9 and the lower electrode 3 . The insulating layer Z4 is provided on the same layer as the lower electrode 3 . The insulating layers Z3 and Z4 can be made of, for example, aluminum oxide (Al2O3) or aluminum nitride (AlN). In the imaging device P3, the contact layer 8 is configured to penetrate the insulating layer Z4, the insulating layer Z3, and the insulating layer Z to connect the semiconductor layer 9 and the wiring layer M, for example. As a material forming the semiconductor layer 9, a material having a large bandgap value (for example, a bandgap value of 3.0 eV or more) and having a higher mobility than the material forming the photoelectric conversion layer 4 can be used. preferable. Specific examples include oxide semiconductor materials such as IGZO; transition metal dichalcogenides; silicon carbide; diamond; graphene; carbon nanotubes;

The lower electrode 3 forms a kind of capacitor together with the insulating layer Z3 and the semiconductor layer 9, and charges generated in the photoelectric conversion layer 4 are transferred to the lower electrode through a part of the semiconductor layer 9, for example, the insulating layer Z3 of the semiconductor layer 9. 3 is stored in the area corresponding to the number 3.

[Third Modification]
FIG. 4 is a cross-sectional view schematically showing an imaging device P4 as a third modified example of the first embodiment of the present disclosure. The imaging element P4 is also a specific example corresponding to the "photoelectric conversion element" of the present disclosure.

In the imaging device P4, as shown in FIG. 4, the reflective layer 2 is curved so as to have a concave surface 2U that is recessed toward the photoelectric conversion layer 4. The configuration of the imaging device P4 is substantially the same as the configuration of the imaging device P2 except that the reflective layer 2 has a concave surface 2U.

In the imaging device P4, the reflective layer 2 has the concave surface 2U, so the obliquely incident light that has passed through the lower electrode 3 is reflected by the concave surface 2U and then enters the photoelectric conversion layer 4 again. Therefore, it is expected that the photoelectric conversion efficiency in the photoelectric conversion layer 4 is further improved.

<2. Second Embodiment>
[Configuration of imaging device 10]
Next, referring to FIG. 5, an imaging apparatus 10 as a second embodiment to which the imaging elements P1 to P4 described in the first embodiment and the modified example can be applied will be described.

(Overall configuration example)
FIG. 5 shows an overall configuration example of a solid-state imaging device 1 according to an embodiment of the present disclosure. The solid-state imaging device 1 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The solid-state imaging device 1 takes in incident light (image light) from a subject, for example, via an optical lens system, converts the incident light imaged on the imaging surface into an electric signal for each pixel, and outputs the electric signal as a pixel signal. It's like The solid-state imaging device 1 includes, for example, a semiconductor substrate 11, a pixel section 100 as an imaging area, a vertical driving circuit 111, a column signal processing circuit 112, a horizontal driving circuit 113, and an output It has a circuit 114 , a control circuit 115 and an input/output terminal 116 . This solid-state imaging device 1 is a specific example corresponding to the "photodetector" of the present disclosure.

The pixel unit 100 has, for example, a plurality of pixels P arranged two-dimensionally in a matrix. The pixel unit 100 includes, for example, pixel rows each composed of a plurality of pixels P arranged in the horizontal direction (horizontal direction of the paper) and pixel columns composed of a plurality of pixels P arranged in the vertical direction (the vertical direction of the paper). Multiple are provided. In the pixel section 100, for example, one pixel drive line Lread (row selection line and reset control line) is wired for each pixel row, and one vertical signal line Lsig is wired for each pixel column. The pixel drive line Lread transmits a drive signal for signal readout from each pixel P. FIG. The ends of the plurality of pixel drive lines Lread are connected to the plurality of output terminals corresponding to the pixel rows of the vertical drive circuit 111, respectively.

The vertical drive circuit 111 is composed of a shift register, an address decoder, and the like, and is a pixel drive section that drives each pixel P in the pixel section 100, for example, in units of pixel rows. A signal output from each pixel P in a pixel row selectively scanned by the vertical driving circuit 111 is supplied to the column signal processing circuit 112 through each vertical signal line Lsig.

The column signal processing circuit 112 is composed of amplifiers, horizontal selection switches, etc. provided for each vertical signal line Lsig.

The horizontal drive circuit 113 is composed of a shift register, an address decoder, etc., and sequentially drives the horizontal selection switches of the column signal processing circuit 112 while scanning them. By the selective scanning by the horizontal driving circuit 113, the signals of the pixels P transmitted through each of the plurality of vertical signal lines Lsig are sequentially output to the horizontal signal line 121, and are output to the outside of the semiconductor substrate 11 through the horizontal signal line 121. It is designed to be transmitted.

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

A circuit portion consisting of the vertical drive circuit 111, the column signal processing circuit 112, the horizontal drive circuit 113, the horizontal signal line 121 and the output circuit 114 may be formed directly on the semiconductor substrate 11, or may be formed on the external control IC. It may be arranged. Moreover, those circuit portions may be formed on another substrate connected by a cable or the like.

The control circuit 115 receives a clock given from the outside of the semiconductor substrate 11, data instructing an operation mode, etc., and outputs data such as internal information of the pixel P which is an imaging device. The control circuit 115 further has a timing generator that generates various timing signals, and controls the vertical drive circuit 111, the column signal processing circuit 112, the horizontal drive circuit 113, etc. based on the various timing signals generated by the timing generator. It controls driving of peripheral circuits.

The input/output terminal 116 exchanges signals with the outside.

In the imaging device 10, one pixel P among the plurality of pixels P arranged in a matrix in the pixel unit 100 is provided with the imaging elements P1 to P4 described in the first embodiment and its modification. can be applied. As a result, long-term reliability is excellent, and high imaging performance can be obtained in spite of its small size.

<4. Examples of application to electronic devices>
FIG. 6 is a block diagram showing a configuration example of an electronic device 2000 to which the present technology is applied. Electronic device 2000 has a function as a camera, for example.

An electronic device 2000 includes an optical unit 2001 including a group of lenses, a photodetector 2002 to which the above-described solid-state imaging device 1 or the like (hereinafter referred to as the solid-state imaging device 1 or the like) is applied, and a DSP (which is a camera signal processing circuit). Digital Signal Processor) circuit 2003 is provided. Electronic device 2000 also includes frame memory 2004 , display unit 2005 , recording unit 2006 , operation unit 2007 , and power supply unit 2008 . DSP circuit 2003 , frame memory 2004 , display unit 2005 , recording unit 2006 , operation unit 2007 and power supply unit 2008 are interconnected via bus line 2009 .

The optical unit 2001 captures incident light (image light) from a subject and forms an image on the imaging surface of the photodetector 2002 . The photodetector 2002 converts the amount of incident light imaged on the imaging surface by the optical unit 2001 into an electric signal for each pixel, and outputs the electric signal as a pixel signal.

The display unit 2005 is composed of, for example, a panel-type display device such as a liquid crystal panel or an organic EL panel, and displays moving images or still images captured by the photodetector 2002 . A recording unit 2006 records a moving image or still image captured by the photodetector 2002 in a recording medium such as a hard disk or a semiconductor memory.

The operation unit 2007 issues operation commands for various functions of the electronic device 2000 under the user's operation. A power supply unit 2008 appropriately supplies various power supplies as operating power supplies for the DSP circuit 2003, the frame memory 2004, the display unit 2005, the recording unit 2006, and the operation unit 2007 to these supply targets.

As described above, by using the imaging device 10 described above as the photodetection device 2002, acquisition of a good image can be expected.

<5. Example of application to moving objects>
The technology (the present technology) according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can be realized as a device mounted on any type of moving body such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility, airplanes, drones, ships, and robots. may

FIG. 7 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile control system to which the technology according to the present disclosure can be applied.

A vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in FIG. 7, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an exterior information detection unit 12030, an interior information detection unit 12040, and an integrated control unit 12050. Also, as the functional configuration of the integrated control unit 12050, a microcomputer 12051, an audio/image output unit 12052, and an in-vehicle network I/F (Interface) 12053 are illustrated.

The drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the driving system control unit 12010 includes a driving force generator for generating driving force of the vehicle such as an internal combustion engine or a driving motor, a driving force transmission mechanism for transmitting the driving force to the wheels, and a steering angle of the vehicle. It functions as a control device such as a steering mechanism to adjust and a brake device to generate braking force of the vehicle.

The body system control unit 12020 controls the operation of various devices equipped on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as headlamps, back lamps, brake lamps, winkers or fog lamps. In this case, the body system control unit 12020 can receive radio waves transmitted from a portable device that substitutes for a key or signals from various switches. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, etc. of the vehicle.

The vehicle exterior information detection unit 12030 detects information outside the vehicle in which the vehicle control system 12000 is installed. For example, the vehicle exterior information detection unit 12030 is connected with an imaging section 12031 . The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image of the exterior of the vehicle, and receives the captured image. The vehicle exterior information detection unit 12030 may perform object detection processing or distance detection processing such as people, vehicles, obstacles, signs, or characters on the road surface based on the received image.

The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of received light. The imaging unit 12031 can output the electric signal as an image, and can also output it as distance measurement information. Also, the light received by the imaging unit 12031 may be visible light or non-visible light such as infrared rays.

The in-vehicle information detection unit 12040 detects in-vehicle information. The in-vehicle information detection unit 12040 is connected to, for example, a driver state detection section 12041 that detects the state of the driver. 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 detects the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041. It may be calculated, or it may be determined whether the driver is dozing off.

The microcomputer 12051 calculates control target values for the driving force generator, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, and controls the drive system control unit. A control command can be output to 12010 . For example, the microcomputer 12051 realizes the functions of ADAS (Advanced Driver Assistance System) including collision avoidance or shock mitigation of vehicles, follow-up driving based on inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane deviation warning, etc. Cooperative control can be performed for the purpose of

In addition, the microcomputer 12051 controls the driving force generator, the steering mechanism, the braking device, etc. based on the information about the vehicle surroundings acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, so that the driver's Cooperative control can be performed for the purpose of autonomous driving, etc., in which vehicles autonomously travel without depending on operation.

Also, the microcomputer 12051 can output a control command to the body system control unit 12030 based on the information outside the vehicle acquired by the information detection unit 12030 outside the vehicle. For example, the microcomputer 12051 controls the headlamps according to the position of the preceding vehicle or the oncoming vehicle detected by the vehicle exterior information detection unit 12030, and performs cooperative control aimed at anti-glare such as switching from high beam to low beam. It can be carried out.

The audio/image output unit 12052 transmits at least one of audio and/or image output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle. In the example of FIG. 7, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are illustrated as output devices. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

FIG. 8 is a diagram showing an example of the installation position of the imaging unit 12031. FIG.

In FIG. 8, the imaging unit 12031 includes

imaging units

12101, 12102, 12103, 12104, and 12105.

The

imaging units

12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and windshield of the vehicle 12100, for example. An image pickup unit 12101 provided in the front nose and an image pickup unit 12105 provided above the windshield in the passenger compartment mainly acquire images in front of the vehicle 12100 .

Imaging units

12102 and 12103 provided in the side mirrors mainly acquire side images of the vehicle 12100 . An imaging unit 12104 provided in the rear bumper or back door mainly acquires an image behind the vehicle 12100 . The imaging unit 12105 provided above the windshield in the passenger compartment is mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, and the like.

It should be noted that FIG. 8 shows an example of the imaging range of the imaging units 12101 to 12104 . The imaging range 12111 indicates the imaging range of the imaging unit 12101 provided in the front nose, the imaging ranges 12112 and 12113 indicate the imaging ranges of the

imaging units

12102 and 12103 provided in the side mirrors, respectively, and the imaging range 12114 The imaging range of an imaging unit 12104 provided on the rear bumper or back door is shown. For example, by superimposing the image data captured by the imaging units 12101 to 12104, a bird's-eye view image of the vehicle 12100 viewed from above can be obtained.

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

For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 determines the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and changes in this distance over time (relative velocity with respect to the vehicle 12100). , it is possible to extract, as the preceding vehicle, the closest three-dimensional object on the traveling path of the vehicle 12100, which runs at a predetermined speed (for example, 0 km/h or more) in substantially the same direction as the vehicle 12100. can. Furthermore, the microcomputer 12051 can set the inter-vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including following stop control) and automatic acceleration control (including following start control). In this way, cooperative control can be performed for the purpose of automatic driving in which the vehicle runs autonomously without relying on the operation of the driver.

For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 converts three-dimensional object data related to three-dimensional objects to other three-dimensional objects such as motorcycles, ordinary vehicles, large vehicles, pedestrians, and utility poles. It can be classified and extracted and used for automatic avoidance of obstacles. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into those that are visible to the driver of the vehicle 12100 and those that are difficult to see. Then, the microcomputer 12051 judges the collision risk indicating the degree of danger of collision with each obstacle, and when the collision risk is equal to or higher than the set value and there is a possibility of collision, an audio speaker 12061 and a display unit 12062 are displayed. By outputting an alarm to the driver via the drive system control unit 12010 and performing forced deceleration and avoidance steering via the drive system control unit 12010, driving support for collision avoidance can be performed.

At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not the pedestrian exists in the captured images of the imaging units 12101 to 12104 . Such recognition of a pedestrian is performed by, for example, a procedure for extracting feature points in images captured by the imaging units 12101 to 12104 as infrared cameras, and performing pattern matching processing on a series of feature points indicating the outline of an object to determine whether or not the pedestrian is a pedestrian. This is done by a procedure that determines When the microcomputer 12051 determines that a pedestrian exists in the images captured by the imaging units 12101 to 12104 and recognizes the pedestrian, the audio image output unit 12052 outputs a rectangular outline for emphasis to the recognized pedestrian. is superimposed on the display unit 12062 . Also, the audio/image output unit 12052 may control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

An example of a vehicle control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 12031 among the configurations described above. Specifically, for example, the imaging device P1 in FIG. 1 can be applied to the imaging unit 12031 . By applying the technology according to the present disclosure to the imaging unit 12031, it is possible to obtain a captured image that is easier to see, thereby reducing driver fatigue.

<6. Example of application to an endoscopic surgery system>
The technology (the present technology) according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

FIG. 9 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (this technology) can be applied.

FIG. 9 illustrates a state in which an operator (doctor) 11131 is performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000 . As illustrated, an endoscopic surgery system 11000 includes an endoscope 11100, other surgical instruments 11110 such as a pneumoperitoneum tube 11111 and an energy treatment instrument 11112, and a support arm device 11120 for supporting the endoscope 11100. , and a cart 11200 loaded with various devices for endoscopic surgery.

An endoscope 11100 is composed of a lens barrel 11101 whose distal end is inserted into the body cavity of a patient 11132 and a camera head 11102 connected to the proximal end of the lens barrel 11101 . In the illustrated example, an endoscope 11100 configured as a so-called rigid scope having a rigid lens barrel 11101 is illustrated, but the endoscope 11100 may be configured as a so-called flexible scope having a flexible lens barrel. good.

The tip of the lens barrel 11101 is provided with an opening into which the objective lens is fitted. 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 11101 by a light guide extending inside the lens barrel 11101, where it reaches the objective. Through the lens, the light is irradiated toward the observation object inside the body cavity of the patient 11132 . Note that the endoscope 11100 may be a straight scope, a perspective scope, or a side scope.

An optical system and an imaging element are provided inside the camera head 11102, and the reflected light (observation light) from the observation target is focused on the imaging element by the optical system. The imaging device photoelectrically converts the observation light to generate an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image. The image signal is transmitted to a camera control unit (CCU: Camera Control Unit) 11201 as RAW data.

The CCU 11201 is composed of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and controls the operations of the endoscope 11100 and the display device 11202 in an integrated manner. Further, the CCU 11201 receives an image signal from the camera head 11102 and performs various image processing such as development processing (demosaicing) for displaying an image based on the image signal.

The display device 11202 displays an image based on an image signal subjected to image processing by the CCU 11201 under the control of the CCU 11201 .

The light source device 11203 is composed of a light source such as an LED (light emitting diode), for example, and supplies the endoscope 11100 with irradiation light for imaging a surgical site or the like.

The input device 11204 is an input interface for the endoscopic surgery system 11000. The 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 or the like to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) by the endoscope 11100 .

The treatment instrument control device 11205 controls driving of the energy treatment instrument 11112 for tissue cauterization, incision, blood vessel sealing, or the like. The pneumoperitoneum device 11206 inflates the body cavity of the patient 11132 for the purpose of securing the visual field of the endoscope 11100 and securing the operator's working space, and injects gas into the body cavity through the pneumoperitoneum tube 11111. send in. The recorder 11207 is a device capable of recording various types of information regarding surgery. The printer 11208 is a device capable of printing various types of information regarding surgery in various formats such as text, images, and graphs.

It should be noted that the light source device 11203 that supplies the endoscope 11100 with irradiation light for photographing the surgical site can be composed of, for example, a white light source composed of an LED, a laser light source, or a combination thereof. When a white light source is configured by a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high accuracy. It can be carried out. Further, in this case, the observation target is irradiated with laser light from each of the RGB laser light sources in a time-division manner, and by controlling the drive of the imaging element of the camera head 11102 in synchronization with the irradiation timing, each of RGB can be handled. It is also possible to pick up images by time division. According to this method, a color image can be obtained without providing a color filter in the imaging element.

Further, the driving of the light source device 11203 may be controlled so as to change the intensity of the output light every predetermined time. By controlling the drive of the imaging device of the camera head 11102 in synchronism with the timing of the change in the intensity of the light to obtain an image in a time-division manner and synthesizing the images, a high dynamic A range of images can be generated.

Also, the light source device 11203 may be configured to be able to supply light in a predetermined wavelength band corresponding to special light observation. In special light observation, for example, the wavelength dependence of light absorption in body tissues is used to irradiate a narrower band of light than the irradiation light (i.e., white light) used during normal observation, thereby observing the mucosal surface layer. So-called Narrow Band Imaging, in which a predetermined tissue such as a blood vessel is imaged with high contrast, is performed. Alternatively, in special light observation, fluorescence observation may be performed in which an image is obtained from fluorescence generated by irradiation with excitation light. In fluorescence observation, the body tissue is irradiated with excitation light and the fluorescence from the body tissue is observed (autofluorescence observation), or a reagent such as indocyanine green (ICG) is locally injected into the body tissue and the body tissue is examined. A fluorescence image can be obtained by irradiating excitation light corresponding to the fluorescence wavelength of the reagent. The light source device 11203 can be configured to be able to supply narrowband light and/or excitation light corresponding to such special light observation.

FIG. 10 is a block diagram showing an example of functional configurations of the camera head 11102 and CCU 11201 shown in FIG.

The camera head 11102 has a lens unit 11401, an imaging section 11402, a drive section 11403, a communication section 11404, and a camera head control section 11405. The CCU 11201 has a communication section 11411 , an image processing section 11412 and a control section 11413 . The camera head 11102 and the CCU 11201 are communicably connected to each other via a transmission cable 11400 .

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

The number of imaging elements constituting the imaging unit 11402 may be one (so-called single-plate type) or plural (so-called multi-plate type). When the image pickup unit 11402 is configured as a multi-plate type, for example, image signals corresponding to RGB may be generated by each image pickup element, and a color image may be obtained by synthesizing the image signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for respectively acquiring right-eye and left-eye image signals corresponding to 3D (dimensional) display. The 3D display enables the operator 11131 to more accurately grasp the depth of the living tissue in the surgical site. Note that when the imaging unit 11402 is configured as a multi-plate type, a plurality of systems of lens units 11401 may be provided corresponding to each imaging element.

Also, 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.

The drive 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 control from the camera head control unit 11405 . Thereby, the magnification and focus of the image captured by the imaging unit 11402 can be appropriately adjusted.

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

Also, the communication unit 11404 receives a control signal for controlling driving of the camera head 11102 from the CCU 11201 and supplies it to the camera head control unit 11405 . The control signal includes, for example, information to specify the frame rate of the captured image, information to specify the exposure value at the time of imaging, and/or information to specify the magnification and focus of the captured image. Contains information about conditions.

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

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

The communication unit 11411 is composed of a communication device for transmitting and receiving various information to and from the camera head 11102 . The communication unit 11411 receives image signals transmitted from the camera head 11102 via the transmission cable 11400 .

Also, the communication unit 11411 transmits a control signal for controlling driving of the camera head 11102 to the camera head 11102 . Image signals and control signals can be transmitted by electric communication, optical communication, or the like.

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

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

In addition, the control unit 11413 causes the display device 11202 to display a captured image showing the surgical site and the like based on the image signal that has undergone 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 techniques. For example, the control unit 11413 detects the shape, color, and the like of the edges of objects included in the captured image, thereby detecting surgical instruments such as forceps, specific body parts, bleeding, mist during use of the energy treatment instrument 11112, and the like. can recognize. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition result to display various types of surgical assistance information superimposed on the image of the surgical site. By superimposing and presenting the surgery support information to the operator 11131, the burden on the operator 11131 can be reduced and the operator 11131 can proceed with the surgery reliably.

A transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable compatible with electrical signal communication, an optical fiber compatible with optical communication, or a composite cable of these.

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

An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to, for example, the imaging unit 11402 of the camera head 11102 among the configurations described above. Specifically, for example, the imaging element P1 in FIG. 1 can be applied to the imaging unit 11402 . By applying the technology according to the present disclosure to the imaging unit 11402, a clearer image of the surgical site can be obtained, so that the operator can reliably check the surgical site.

Although the endoscopic surgery system has been described as an example here, the technology according to the present disclosure may also be applied to, for example, a microsurgery system.

<7. Experimental example>
The present disclosure will be specifically described below with some experimental examples. However, the present disclosure is not limited only to the following experimental examples.

(Structure of image sensor)
[Example 1]
As Example 1, a sample of the imaging device P1 shown in FIG. 1 was produced. Here, a reflective layer 2, a lower electrode 3, a buffer layer 6, a photoelectric conversion layer 4, a buffer layer 7, and an upper electrode 5 are sequentially laminated on a substrate 1 by a vacuum sputtering method, a vacuum evaporation method, or a spin coating method. I made it The reflective layer 2 was formed of Al (aluminum) to a thickness of 50 nm. The lower electrode 3 was formed of ITO to a thickness of 50 nm. Moreover, the photoelectric conversion layer 4 was formed to have a thickness of 120 nm.

[Example 2]
As Example 2, a sample of the imaging device P1 shown in FIG. 1 was produced. Here, the photoelectric conversion layer 4 was made to have a thickness of 240 nm. A sample of Example 2 was produced so as to have the same configuration as that of Example 1 except for this point.

[Comparative Example 1]
As Comparative Example 1, a sample of an imaging device having a configuration in which the reflective layer 2 was removed from the configuration of the imaging device P1 shown in FIG. 1 was manufactured. The configuration of Comparative Example 1 was the same as that of Example 1 except for this point.

[Comparative Example 2]
As Comparative Example 2, a sample of an imaging device having a configuration in which the reflective layer 2 was removed from the configuration of the imaging device P1 shown in FIG. 1 was manufactured. Except for this point, the configuration of Comparative Example 2 was the same as that of Example 2.

[Comparative Example 3]
As Comparative Example 3, a sample of an imaging device having a configuration in which the reflective layer 2 was removed from the imaging device P1 shown in FIG. 1 was manufactured. Furthermore, in Comparative Example 3, the lower electrode 3 was formed of Al (aluminum) so as to have a thickness of 50 nm. That is, in Comparative Example 3, the lower electrode 3 acted as a reflective layer on the photoelectric conversion layer 4 .

(Performance evaluation of imaging device)
External quantum efficiency (EQE), responsiveness, presence/absence of resistance increase, presence/absence of change in work function, presence/absence of metal elution, and 1400 nm light for the samples of the imaging devices of Examples 1 and 2 and Comparative Examples 1 and 3. The reflectance for each was evaluated. The results are collectively shown in FIG. Note that FIG. 11 also shows information on the thickness of the lower electrode, the reflective layer, the cross-sectional structure, and the photoelectric conversion layer in the samples of the imaging elements of Examples 1 and 2 and Comparative Examples 1 and 3. there is

As for the reflectance, an ultraviolet-visible-near-infrared spectrophotometer V770 (manufactured by JASCO Corporation) having an integrating sphere was used to measure the reflectance of light with a wavelength of 1400 nm in reflection mode.

FIG. 12A shows the wavelength dependence of the reflectance [%] for each of the Al/ITO two-layer film, the Al single-layer film, and the ITO single-layer film. Here, three types of samples each having an Al/ITO two-layer film, an Al single-layer film, or an ITO single-layer film formed on a glass substrate were examined from the opposite side of the glass substrate in a wavelength range of 300 nm to 1600 nm. I set it to irradiate the following light. Further, FIG. 12B shows the wavelength dependence of the reflectance [%] for each of the Cu/ITO two-layer film, the Cu single-layer film, and the ITO single-layer film. Here, for three types of samples in which a Cu/ITO two-layer film, a Cu single-layer film, or an ITO single-layer film were formed on a glass substrate, the wavelength range of 300 nm to 1600 nm was measured from the opposite side of the glass substrate. I set it to irradiate the following light. From the results of FIG. 12A, it was found that the Al/ITO two-layer film exhibited a sufficiently high reflectance compared to the ITO single-layer film. From the results of FIG. 12B, it was found that the Cu/ITO two-layer film exhibited a sufficiently high reflectance compared to the ITO single-layer film.

As shown in FIG. 11, in Examples 1 and 2, good performance was obtained in terms of external quantum efficiency (EQE) and responsiveness. Moreover, in Examples 1 and 2, no increase in resistance, no change in work function, and no metal elution were observed. Furthermore, the reflective layer 2 exhibited a high reflectance of 93% to 95%.

On the other hand, in Comparative Example 1, a decrease in external quantum efficiency (EQE) was observed compared to Example 1. Moreover, in Comparative Example 2, a decrease in external quantum efficiency (EQE) was observed as compared with Example 2. In Comparative Examples 1 and 2, it is considered that the absence of the reflective layer 2 causes a decrease in external quantum efficiency (EQE). Moreover, in Comparative Example 3, sufficient performance was not obtained in both external quantum efficiency (EQE) and responsiveness. Furthermore, in Comparative Examples 3 and 4, an increase in resistance, a change in work function, and metal elution were observed. This is considered to be due to the formation of an oxide film on the surface of the lower electrode 3 .

(summary)
From the above results, it was confirmed that according to the imaging device of the present disclosure, it is possible to ensure both excellent external quantum efficiency (EQE) and excellent responsiveness. In addition, in Examples 1 and 2, no increase in resistance, change in work function, and metal elution were observed. , it was also confirmed that high long-term reliability can be obtained.

<8. Other modified examples>
As described above, the present disclosure has been described by citing several embodiments, modifications, and application examples or application examples thereof (hereinafter referred to as embodiments, etc.), but the present disclosure is limited to the above embodiments, etc. Various modifications are possible. For example, the photoelectric conversion element of the present disclosure may be the imaging element P5 having the configuration shown in FIG. The image pickup device P5 has a photoelectric conversion section composed of a laminated structure of a lower electrode 11 , an organic photoelectric conversion layer 13 and an upper electrode 12 . A reflective layer 14 is provided on the side of the lower electrode 11 opposite to the organic photoelectric conversion layer 13 . The imaging device P5 further includes a control section provided on the semiconductor substrate 70 and connected to the lower electrode 11, and the photoelectric conversion section is arranged above the semiconductor substrate 70. FIG. Here, the light incident surface of the semiconductor substrate 70 is the upper side, and the opposite side of the semiconductor substrate 70 is the lower side. A wiring layer 62 composed of a plurality of wirings is provided under the semiconductor substrate 70 . In addition, the semiconductor substrate 70 is provided with at least a charge storage portion (floating diffusion layer FD) and an amplification transistor TR1, which constitute a control portion, and the lower electrode 11 is connected to the floating diffusion layer FD and the gate portion of the amplification transistor TR1. It is connected. The charge storage portion (floating diffusion layer FD1) stores charges generated in the organic photoelectric conversion layer 13 . The semiconductor substrate 70 is further provided with a reset transistor TR2 and a selection transistor TR3 that constitute a control section. The floating diffusion layer FD1 is connected to one source/drain region of the reset transistor TR2, and one source/drain region of the amplification transistor TR1 is connected to one source/drain region of the selection transistor TR3. The other source/drain region of the selection transistor TR3 is connected to the signal line.

Specifically, the image pickup device P5 in FIG. 13 is a front side illumination type image pickup device. The reflective layer 14 is formed on the interlayer insulating layer 81 in the imaging device P5. The reflective layer 14 is made of a metal such as copper or aluminum, like the reflective layer 2 of the first embodiment. A lower electrode 11 is provided on the reflective layer 14 . A first organic material layer (hole injection blocking layer), a second organic material layer, an organic photoelectric conversion layer 13 and an electron injection blocking layer are formed on the lower electrode 11, and an upper electrode 12 is formed on the electron injection blocking layer. is formed. A protective layer 82 is formed on the entire surface including the upper electrode 12 . An on-chip micro lens 90 is provided on the protective layer 82 . The lower electrode 11 and the upper electrode 12 are composed of transparent electrodes made of ITO, for example. The interlayer insulating layer 81 and protective layer 82 are made of well-known insulating materials (such as SiO ₂ and SiN).

An element isolation region 71 is formed on the side of the first surface 70A of the semiconductor substrate 70, and an oxide film 72 is formed on the first surface 70A of the semiconductor substrate 70. Further, on the first surface 70A side of the semiconductor substrate 70, a reset transistor TR2, an amplification transistor TR1, a selection transistor TR3, and a first floating diffusion layer FD1 are provided.

Even with such an image pickup device P5, the same effect as that of the image pickup device P1 of the first embodiment can be expected.

Also, the various materials described in the above embodiments and the like are examples, and the present disclosure is not limited to these.

In the photoelectric conversion element as one embodiment of the present disclosure, since the reflective layer is provided separately from the second electrode, the second electrode can be made of a material other than metal. Therefore, it is possible to avoid an increase in resistance due to an oxide film, a change in work function, or elution of metal into the photoelectric conversion layer, which may occur when the second electrode is formed of metal. Therefore, the performance of the photoelectric conversion element can be stabilized. Further, by providing the reflective layer, the optical path length can be lengthened even when the photoelectric conversion layer is thinned, and a decrease in photoelectric conversion efficiency can be suppressed (a decrease in EQE can be suppressed).
Note that the effects described in this specification are merely examples and are not limited to the descriptions, and other effects may be provided. In addition, the present technology can take the following configurations.
(1)
a first electrode that transmits light in a first wavelength range;
a second electrode facing the first electrode and transmitting light in the first wavelength band;
a photoelectric conversion layer positioned between the first electrode and the second electrode for detecting light in the first wavelength band and performing photoelectric conversion;
light in the first wavelength region located on the opposite side of the photoelectric conversion layer as viewed from the second electrode and transmitted through the first electrode, the photoelectric conversion layer, and the second electrode to the photoelectric conversion layer; A photoelectric conversion element including a laminated structure having a reflective layer that reflects toward the surface.
(2)
The photoelectric conversion element according to (1) above, wherein the first electrode and the second electrode are indium tin oxide (ITO).
(3)
The photoelectric conversion element according to (1) or (2) above, wherein the reflective layer contains a metal as a main component.
(4)
The photoelectric conversion element according to (3) above, wherein the metal is aluminum (Al), Cu (copper), Ag (silver), or Au (gold).
(5)
The photoelectric conversion element according to any one of (1) to (4) above, wherein the second electrode and the reflective layer are in direct contact.
(6)
The photoelectric conversion element according to any one of (1) to (4) above, further comprising an insulating layer positioned between the second electrode and the reflective layer.
(7)
The photoelectric conversion element according to any one of (1) to (6) above, wherein the reflective layer has a concave surface facing the photoelectric conversion layer.
(8)
The photoelectric conversion element according to any one of (1) to (7) above, wherein the laminated structure further includes a semiconductor layer positioned between the second electrode and the photoelectric conversion layer.
(9)
Equipped with multiple photoelectric conversion elements,
The photoelectric conversion element is
a first electrode that transmits light in a first wavelength range;
a second electrode facing the first electrode and transmitting light in the first wavelength range;
a photoelectric conversion layer positioned between the first electrode and the second electrode for detecting light in the first wavelength band and performing photoelectric conversion;
light in the first wavelength region located on the opposite side of the photoelectric conversion layer as viewed from the second electrode and transmitted through the first electrode, the photoelectric conversion layer, and the second electrode to the photoelectric conversion layer; A photodetector device comprising a laminate structure having a reflective layer that reflects toward and a reflective layer.
(10)
Equipped with an optical unit, a signal processing unit, and a photoelectric conversion element,
The photoelectric conversion element is
a first electrode that transmits light in a first wavelength range;
a second electrode facing the first electrode and transmitting light in the first wavelength range;
a photoelectric conversion layer positioned between the first electrode and the second electrode for detecting light in the first wavelength band and performing photoelectric conversion;
light in the first wavelength region located on the opposite side of the photoelectric conversion layer as viewed from the second electrode and transmitted through the first electrode, the photoelectric conversion layer, and the second electrode to the photoelectric conversion layer; An electronic device comprising a laminated structure having a reflective layer that reflects toward the surface.

This application claims priority based on Japanese Patent Application No. 2021-108123 filed on June 29, 2021 at the Japan Patent Office, and the entire contents of this application are incorporated herein by reference. to refer to.

Depending on design requirements and other factors, those skilled in the art may conceive various modifications, combinations, subcombinations, and modifications that fall within the scope of the appended claims and their equivalents. It is understood that

Claims

a first electrode that transmits light in a first wavelength range;
a second electrode facing the first electrode and transmitting light in the first wavelength band;
a photoelectric conversion layer positioned between the first electrode and the second electrode for detecting light in the first wavelength band and performing photoelectric conversion;
light in the first wavelength region located on the opposite side of the photoelectric conversion layer as viewed from the second electrode and transmitted through the first electrode, the photoelectric conversion layer, and the second electrode to the photoelectric conversion layer; A photoelectric conversion element including a laminated structure having a reflective layer that reflects toward the surface.
The photoelectric conversion device according to claim 1, wherein the first electrode and the second electrode are indium tin oxide (ITO).
The photoelectric conversion device according to claim 1, wherein the reflective layer contains metal as a main component.
The photoelectric conversion element according to claim 3, wherein the metal is aluminum (Al), Cu (copper), Ag (silver) or Au (gold).
The photoelectric conversion element according to claim 1, wherein the second electrode and the reflective layer are in direct contact.
2. The photoelectric conversion device according to claim 1, further comprising an insulating layer located between said second electrode and said reflective layer.
The photoelectric conversion element according to claim 1, wherein the reflective layer has a concave surface facing the photoelectric conversion layer.
2. The photoelectric conversion element according to claim 1, wherein the laminated structure further includes a semiconductor layer positioned between the second electrode and the photoelectric conversion layer.
Equipped with multiple photoelectric conversion elements,
The photoelectric conversion element is
a first electrode that transmits light in a first wavelength range;
a second electrode facing the first electrode and transmitting light in the first wavelength range;
a photoelectric conversion layer positioned between the first electrode and the second electrode for detecting light in the first wavelength band and performing photoelectric conversion;
light in the first wavelength region located on the opposite side of the photoelectric conversion layer as viewed from the second electrode and transmitted through the first electrode, the photoelectric conversion layer, and the second electrode to the photoelectric conversion layer; A photodetector device comprising a laminate structure having a reflective layer that reflects toward and a reflective layer.
Equipped with an optical unit, a signal processing unit, and a photoelectric conversion element,
The photoelectric conversion element is
a first electrode that transmits light in a first wavelength range;
a second electrode facing the first electrode and transmitting light in the first wavelength range;
a photoelectric conversion layer positioned between the first electrode and the second electrode for detecting light in the first wavelength band and performing photoelectric conversion;
light in the first wavelength region located on the opposite side of the photoelectric conversion layer as viewed from the second electrode and transmitted through the first electrode, the photoelectric conversion layer, and the second electrode to the photoelectric conversion layer; An electronic device comprising a laminated structure having a reflective layer that reflects toward the surface.