Array sensor

Abstract

A first light-receiving element of this array sensor outputs, from an output unit 32, a first output signal corresponding to the intensity of incident light. A second light-receiving element of the array sensor has a phototransistor structure including a gate electrode, a source electrode, a drain electrode, and a photoelectric conversion unit. In the second light-receiving element, electric current flows between the source electrode and the drain electrode in accordance with the intensity of light incident on the photoelectric conversion unit, at a gain corresponding to a voltage applied to the gate electrode. The output unit of the first light-receiving element is electrically connected to the gate electrode of the second light-receiving element, and the gain of the second light-receiving element changes in accordance with the first output signal outputted from the output unit of the first light-receiving element. A signal based on at least a second output signal from the second light-receiving element is outputted.

Description

Array sensor

[0001] One aspect of the present disclosure relates to an array sensor.

[0002] Non-Patent Document 1 describes a sensor including a dynamic photoelectric conversion element and eight static photoelectric conversion elements arranged around the dynamic photoelectric conversion element. In this sensor, signals from the eight static photoelectric conversion elements are output to an external circuit and processed in the external circuit. Then, the optical responsivity of the dynamic photoelectric conversion element changes according to the processing result in the external circuit. Thereby, it is intended to accurately detect the edge of an object.

[0003] Yang, Y., Pan, C., Li, Y. et al. In-sensor dynamic computing for intelligent machine vision. Nat Electron 7, 225-233(2024). https: / / doi.org / 10.1038 / s41928-024-01124-0

[0004] For a sensor as described above, it may be required to adjust the operation of the sensor according to the intensity of ambient light. Also, reduction of power consumption and suppression of noise may be required together.

[0005] One aspect of the present disclosure aims to provide an array sensor capable of operating in adaptation to ambient light, reducing power consumption, and suppressing noise.

[0006] An array sensor relating to one aspect of the present disclosure includes: [1] a plurality of first light-receiving elements and a plurality of second light-receiving elements, wherein at least one first light-receiving element from the plurality of first light-receiving elements and at least one second light-receiving element from the plurality of second light-receiving elements are arranged in each of a plurality of detection regions arranged in one or two dimensions, each of the plurality of first light-receiving elements outputs a first output signal from an output unit corresponding to the intensity of incident light, each of the plurality of second light-receiving elements has a phototransistor structure including a gate electrode, a source electrode, a drain electrode, and a photoelectric conversion unit, and in each of the plurality of second light-receiving elements, the gate electrode An array sensor in which, with a gain corresponding to the applied voltage, a current flows between the source electrode and the drain electrode in accordance with the intensity of light incident on the photoelectric conversion unit, and in each of the plurality of detection regions, the output section of the at least one first photodetector is electrically connected to the gate electrode of the at least one second photodetector, the gain of the at least one second photodetector changes in accordance with the first output signal output from the output section of the at least one first photodetector, and a signal is output from each of the plurality of detection regions, at least based on the second output signal from the at least one second photodetector.

[0007] In this array sensor, since the second photodetector has a phototransistor structure, the gain of the second photodetector can be adjusted by adjusting the voltage applied to the gate electrode of the second photodetector. More specifically, at least one first photodetector and at least one second photodetector are arranged in each of the multiple detection regions, and in each detection region, the output of at least one first photodetector is electrically connected to the gate electrode of at least one second photodetector, and the gain of at least one second photodetector changes in accordance with the first output signal output from the output of at least one first photodetector. As a result, for each detection region, the gain of at least one second photodetector is adjusted according to the intensity of ambient light incident on at least one first photodetector. Consequently, even if the intensity of ambient light incident on each detection region differs, for example, different gains can be set for each detection region according to the intensity of ambient light. Therefore, the operation of the array sensor can be adjusted according to the intensity of ambient light, and the output can be stabilized. Furthermore, in this array sensor, the output of at least one first photodetector is electrically connected to the gate electrode of at least one second photodetector in each detection area. This eliminates the need for power to drive the external circuit, compared to, for example, a case where the output from the first photodetector is output to an external circuit and processed by the external circuit, thereby reducing power consumption. In addition, the wiring length can be shortened compared to the previous case, and noise generation can be suppressed. Furthermore, the array sensor can be made smaller compared to the previous case. As a result, this array sensor enables operation adapted to ambient light, as well as reduced power consumption and suppression of noise.

[0008] An array sensor relating to one aspect of the present disclosure may be [2] "the array sensor according to [1], wherein the at least one first light-receiving element consists of one first light-receiving element, and the at least one second light-receiving element consists of one second light-receiving element." In this case, it becomes possible to configure a single detection area to be small, increasing the number of detection areas per unit area, and enabling operation adapted to ambient light for each smaller area.

[0009] An array sensor relating to one aspect of this disclosure may be [3] "the array sensor according to [1] wherein the at least one first photodetector includes two or more first photodetectors having different sensitivities." In this case, for example, it becomes possible to widen the dynamic range.

[0010] An array sensor relating to one aspect of this disclosure may be [4] "the array sensor according to any one of [1] to [3] wherein the at least one second photodetector includes two or more second photodetectors having different time response characteristics." In this case, a time filter function can be realized.

[0011] An array sensor relating to one aspect of this disclosure may be [5] "an array sensor according to any one of [1] to [4], wherein the photoelectric conversion unit of each of the plurality of second photodetectors includes a two-dimensional layered material electrically connected to the source electrode and the drain electrode." In this case, the characteristics of the second photodetector, such as the band gap, can be adjusted by selecting atoms and layer configuration in the two-dimensional layered material, and a desired photoresponse can be obtained.

[0012] An array sensor relating to one aspect of the present disclosure may be [6] "an array sensor according to any one of [1] to [5], wherein each of the plurality of first photodetectors has a phototransistor structure including a gate electrode, a source electrode, a drain electrode, and a photoelectric conversion unit." In this case, the gain of the first photodetectors can be adjusted by adjusting the voltage applied to the gate electrode of the first photodetectors. This makes it possible, for example, to adjust the gain of the first photodetectors according to the operating environment of the array sensor (e.g., outdoors / indoors).

[0013] An array sensor relating to one aspect of this disclosure may be [7] "the array sensor according to [6], wherein each of the plurality of first photodetectors includes a two-dimensional layered material electrically connected to the source electrode and the drain electrode." In this case, the characteristics of the first photodetectors, such as the band gap, can be adjusted by selecting atoms and layer configuration in the two-dimensional layered material, and a desired photoresponse can be obtained.

[0014] An array sensor relating to one aspect of the present disclosure may be [8] "an array sensor according to any one of [1] to [7] in which the signals output from each of the plurality of detection regions are based on the second output signal from the at least one second photodetector and not on the first output signal from the at least one first photodetector." In this case, only the second output signal from the second photodetector corresponding to the intensity of ambient light can be reflected in the output.

[0015] An array sensor relating to one aspect of the present disclosure may be an array sensor according to any one of [1] to [7], wherein the signals output from each of the plurality of detection regions are based on the first output signal from the at least one first photodetector and the second output signal from the at least one second photodetector. In this case, in addition to the second output signal from the second photodetector corresponding to the intensity of ambient light, the first output signal from the first photodetector can also be reflected in the output. This makes it possible to effectively utilize the first output signal from the first photodetector.

[0016] An array sensor relating to one aspect of the present disclosure may be

[10] "an array sensor according to any one of [1] to [9] wherein in each of the plurality of detection regions, the total area of ​​the light-receiving surfaces of at least one second light-receiving element is greater than the total area of ​​the light-receiving surfaces of at least one first light-receiving element." In this case, the second output signal from the second light-receiving element can be increased in accordance with the intensity of ambient light.

[0017] An array sensor relating to one aspect of the present disclosure may be

[11] "an array sensor according to any one of [1] to

[10] wherein, in each of the plurality of detection regions, the area of ​​the light-receiving surface of any one of the at least one first light-receiving elements is greater than the area of ​​the light-receiving surface of any one of the at least one second light-receiving elements." In this case, the area of ​​the light-receiving surface of the first light-receiving element can be secured, and sensitivity to changes in ambient light can be improved.

[0018] An array sensor relating to one aspect of the present disclosure may be

[12] "an array sensor according to any one of [1] to

[11] , wherein the gate electrodes of each of the plurality of second photodetectors have a pair of portions spaced apart from each other." In this case, the gain changes linearly with respect to the voltage applied to the gate electrodes, and the phototransistor structure of the second photodetectors can be suitably configured.

[0019] According to one aspect of this disclosure, it is possible to provide an array sensor that can operate in accordance with ambient light, while also reducing power consumption and suppressing noise.

[0020] This is a configuration diagram of an array sensor according to an embodiment. (a) and (b) are cross-sectional views showing examples of the structure of a photodetector. (a), (b) and (c) are cross-sectional views showing examples of the structure of a photodetector. This is a circuit diagram of the first photodetector and the second photodetector. (a) and (b) are diagrams for explaining the operation of the array sensor. (a), (b) and (c) are circuit diagrams for explaining modified versions of the first photodetector. (a), (b) and (c) are circuit diagrams for explaining modified versions of the second photodetector. This is a diagram for explaining modified versions. This is a diagram for explaining modified versions. (a) is a graph showing an example of the time response characteristics of the second photodetector 12A, and (b) is a graph showing an example of the time response characteristics of the second photodetector 12B. (a) is a graph showing an example of the output signal from the detection region, and (b) is a graph showing an example of the frequency response characteristics of the detection region. (a) is a graph showing an example of the time response characteristics of the second photodetector 12A, and (b) is a graph showing an example of the time response characteristics of the second photodetector 12B. (a) is a graph showing an example of the output signal from the detection region, and (b) is a graph showing an example of the frequency response characteristics of the detection region. (a), (b) and (c) are diagrams illustrating modified examples. (a), (b), (c) and (d) are diagrams illustrating modified examples. Diagrams illustrating modified examples. Diagrams illustrating modified examples. (a) and (b) are diagrams illustrating modified examples.

[0021] Embodiments of this disclosure will be described in detail below with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant descriptions will be omitted.

[0022] As shown in Figure 1, the array sensor 1 comprises a plurality of detection regions 10 arranged in two dimensions. In Figure 1, the boundaries of the detection regions 10 are shown by dashed lines. In this example, the array sensor 1 is an image sensor and detects light in each detection region 10. Each detection region 10 corresponds, for example, to a pixel of an image constructed based on the output signal from the image sensor.

[0023] In this example, multiple detection regions 10 are arranged in a grid (matrix) pattern, along each of the mutually orthogonal first direction D1 and second direction D2. Each detection region 10 is formed, for example, in a rectangular shape. Although Figure 1 shows four detection regions 10 arranged along each of the first direction D1 and second direction D2, in reality, more detection regions 10 may be arranged along each of the first direction D1 and second direction D2, and the number of detection regions 10 arranged is not limited.

[0024] Each detection region 10 has a first light-receiving element 11 and a second light-receiving element 12. In each detection region 10, the first light-receiving element 11 and the second light-receiving element 12 are arranged along a first direction D1. In each detection region 10, the first light-receiving element 11 is located on one side of the first direction D1, and the second light-receiving element 12 is located on the other side of the first direction D1. In this example, the first light-receiving element 11 is formed in a substantially rectangular shape, and the second light-receiving element 12 is formed in a substantially square shape that is larger than the first light-receiving element 11. In each detection region 10, the area of ​​the light-receiving surface of the second light-receiving element 12 is larger than the area of ​​the light-receiving surface of the first light-receiving element 11. In Figure 1, the light-receiving surfaces of the first light-receiving element 11 and the second light-receiving element 12 are shown with hatching. In this example, in each detection region 10, the area of ​​the light-receiving surface of the second light-receiving element 12 is larger than twice the area of ​​the light-receiving surface of the first light-receiving element 11. This ensures sufficient output from the second light-receiving element 12. The area of ​​the light-receiving surface of the second light-receiving element 12 is larger than 1 / 3 of the area of ​​the detection region 10. This allows the array sensor 1 to be miniaturized while ensuring sufficient output from the second light-receiving element 12. In the first direction D1, the spacing between adjacent second light-receiving elements 12 in the detection region 10 is smaller than the maximum width of the second light-receiving element 12 in the first direction D1, and in the second direction D2, the spacing between adjacent second light-receiving elements 12 is smaller than the maximum width of the second light-receiving element 12 in the second direction D2. This allows sufficient output from the second light-receiving element 12 while reducing dead space in the array sensor 1.

[0025] The structures of the first light-receiving element 11 and the second light-receiving element 12 will be described with reference to Figures 2 and 3. Figures 2 and 3 show examples of the structures of the light-receiving element section 13 that can constitute the first light-receiving element 11 and the second light-receiving element 12. In the array sensor 1 shown in Figure 1, the first light-receiving element 11 has the structure of the light-receiving element section 13 shown in Figure 2(a), and the second light-receiving element 12 has the structure of the light-receiving element section 13 shown in Figure 3(a).

[0026] In the example shown in Figure 2(a), the light-receiving element 13 has a phototransistor structure 50 including a substrate 21, a gate electrode 22, an insulating layer 23, a source electrode 24, a drain electrode 25, and a photoelectric conversion unit 26. The substrate 21 is made of, for example, silicon dioxide (SiO₂ ２ ) or silicon. The substrate 21 of the photodetector portion 13 constituting the first photodetector 11 and the substrate 21 of the photodetector portion 13 constituting the second photodetector 12 may be different substrates or may be a common substrate. The gate electrode 22 is formed in layers on the substrate 21. The gate electrode 22, source electrode 24 and drain electrode 25 are formed of a metallic material such as titanium or nickel. The insulating layer 23 is formed on the gate electrode 22 on the side opposite to the substrate 21. The insulating layer 23 is made of, for example, silicon dioxide or alumina (Al ２ O ３ It is formed by the following:

[0027] The source electrode 24 and the drain electrode 25 are formed on the insulating layer 23 on the side opposite to the substrate 21. The source electrode 24 and the drain electrode 25 are spaced apart so as to be electrically isolated from each other. In this example, the first photodetector 11 and the second photodetector 12 have a photoelectric conversion section 26 that defines a light-receiving surface. In this example, the entire photoelectric conversion section 26 is positioned to be optically exposed, and the entire surface of the photoelectric conversion section 26 is a light-receiving surface (an effective area capable of converting incident light into an electrical signal). The thickness of the photoelectric conversion section 26 is, for example, about 0.1 nm to 10 nm. The size of the photoelectric conversion section 26 in plan view (viewed from a direction perpendicular to the light-receiving surface) is, for example, about 1 μm to 10 μm in length and width. For example, the first photodetector 11 may be formed in a square shape with a length and width of 2 μm in plan view, and the second photodetector 12 may be formed in a square shape with a length and width of 8 μm in plan view. In this embodiment, the thickness of the photoelectric conversion unit 26 is smaller than the thickness of each of the substrate 21, gate electrode 22, insulating layer 23, source electrode 24, drain electrode 25, and the floating gate electrode 28, which will be described later. In this example, the photoelectric conversion unit 26 consists of a two-dimensional layered material 27. The two-dimensional layered material 27 is formed on the insulating layer 23 so as to be located between the source electrode 24 and the drain electrode 25, and is electrically connected to the source electrode 24 and the drain electrode 25. Note that a two-dimensional layered material may be used as the material for the electrodes (gate electrode 22, source electrode 24, drain electrode 25) or the insulating layer (insulating layer 23, insulating layer 29, which will be described later). In that case, the thickness of the photoelectric conversion unit 26 may be equal to the thickness of the electrodes or insulating layer, or smaller than the thickness of the electrodes or insulating layer.

[0028] The two-dimensional layered material 27 is composed of a material having a crystalline structure in which the interatomic bonds are closed within the layers, and the interlayers are bonded only by weak van der Waals forces. In a two-dimensional layered material, a layered structure is formed by atomic layers that are strongly chemically bonded (covalent bonds) in two dimensions and weakly chemically bonded (van der Waals bonds). In this example, the two-dimensional layered material 27 is a transition metal dichalcogenide (TMD), specifically molybdenum disulfide (MoS ２) is composed of the following. The transition metal dichalcogenide has a layered structure in which a transition metal layer (molybdenum: Mo, tungsten: W, etc.) is sandwiched between two chalcogen (sulfur: S, selenium: Se or tellurium: Te, etc.). The two-dimensional layered material 27 is preferably a material capable of realizing the photogating effect described later, and may contain, for example, graphene, black phosphorus, MXene, etc. The transition metal dichalcogenide constituting the two-dimensional layered material 27 is tungsten selenide (WSe ２ ) is also acceptable.

[0029] The two-dimensional layered material 27 (photoelectric conversion unit 26) is positioned to be exposed to the outside on the opposite side from the substrate 21, and light is incident on the two-dimensional layered material 27. A protective layer that can transmit detection light may be placed on the two-dimensional layered material 27. Since the light-receiving element unit 13 has a phototransistor structure 50, in the light-receiving element unit 13, a current flows between the source electrode 24 and the drain electrode 25 with a gain corresponding to the magnitude of the voltage applied to the gate electrode 22, and in accordance with the intensity of the light incident on the two-dimensional layered material 27. That is, when light is incident on the two-dimensional layered material 27 with a voltage (gate voltage) applied to the gate electrode 22, a current flows between the source electrode 24 and the drain electrode 25 with a gain corresponding to the gate voltage, in accordance with the intensity of the incident light.

[0030] In the photodetector 13, the apparent gate voltage is modulated according to the intensity of light incident on the two-dimensional layered material 27 due to the photogating effect occurring in the two-dimensional layered material 27. The photogating effect is a phenomenon in which an additional electric field is generated when carriers (electrons and holes) generated by light are trapped within the two-dimensional layered material 27. The electric field generated by the trapped carriers shifts the transfer characteristic curve of the transistor (modulating the apparent gate voltage). This photogating effect allows the time response of the photodetector 13 to be controlled.

[0031] The light-receiving element 13 may be configured as shown in Figure 2(b), Figure 3(a), Figure 3(b), or Figure 3(c). In the example of Figure 2(b), the light-receiving element 13 further comprises a floating gate electrode 28 formed on an insulating layer 23 and an insulating layer 29 formed on the floating gate electrode 28. The floating gate electrode 28 is formed of the same metallic material as, for example, the gate electrode 22, source electrode 24, and drain electrode 25. The insulating layer 29 is formed of, for example, silicon dioxide or alumina. In the example of Figure 2(b), the presence of the floating gate electrode 28 allows voltage to be retained on the floating gate electrode 28, thereby reducing power consumption.

[0032] In the examples of Figures 2(a) and 2(b), the gate electrode 22 has a single-gate structure, whereas in the examples of Figures 3(a), 3(b), and 3(c), the gate electrode 22 has a split-gate structure. In the example of Figure 3(a), the gate electrode 22 is composed of two parts 22a, 22a. The two parts 22a, 22a are spaced apart from each other so as to be electrically isolated. For example, voltages of the same magnitude but with different positive and negative values ​​(e.g., 5V and -5V) are applied to parts 22a, 22a. Note that it is sufficient for a potential difference to exist between parts 22a, 22a, and it is not necessarily required that voltages of the same magnitude but with different positive and negative values ​​be applied to parts 22a, 22a.

[0033] The example in Figure 3(b) differs from the example in Figure 3(a) in that the light-receiving element portion 13 further comprises a floating gate electrode 28 and an insulating layer 29. The example in Figure 3(c) differs from the example in Figure 3(b) in that the floating gate electrode 28 is composed of two portions 28a, 28a that are spaced apart from each other so as to be electrically isolated.

[0034] As described above, in the array sensor 1 shown in Figure 1, the first light-receiving element 11 has the structure of the light-receiving element section 13 shown in Figure 2(a), and the second light-receiving element 12 has the structure of the light-receiving element section 13 shown in Figure 3(a). Figure 4 is a circuit diagram of the first light-receiving element 11 and the second light-receiving element 12 in each detection region 10. Hereinafter, the gate electrode 22, source electrode 24, drain electrode 25, and photoelectric conversion section 26 of the first light-receiving element 11 will also be referred to as gate electrode 22A, source electrode 24A, drain electrode 25A, and photoelectric conversion section 26A, and the gate electrode 22, source electrode 24, drain electrode 25, and photoelectric conversion section 26 of the second light-receiving element 12 will also be referred to as gate electrode 22B, source electrode 24B, drain electrode 25B, and photoelectric conversion section 26B.

[0035] As shown in Figure 4, a resistor 31 is connected to the drain electrode 25A of the first light-receiving element 11. The resistor 31 may be a variable resistor or a fixed resistor. The resistor 31 may be provided outside the light-receiving element section 13 and connected to the light-receiving element section 13 via wiring, or it may be formed inside the light-receiving element section 13. A voltage V1 is applied to the resistor 31 by the voltage application section VA. In this example, the drain electrode 25A constitutes the output section 32 of the first light-receiving element 11. In the first light-receiving element 11, a first output signal (voltage signal) corresponding to the intensity of light incident on the photoelectric conversion section 26A is output from the output section 32. The output section 32 of the first light-receiving element 11 is electrically connected to the gate electrode 22B of the second light-receiving element 12 by wiring formed within the detection region 10. Hereinafter, the voltage applied by the voltage application section VA will be V1, the voltage applied to the gate electrode 22A will be V2, and the voltage at the output section 32 (first output signal) will be V3. In the example in Figure 4, the source electrode 24A is connected to ground and a voltage V3 is applied to the drain electrode 25A. However, conversely, the drain electrode 25A may be connected to ground and a voltage V3 may be applied to the source electrode 24A. In the example in Figure 4, the output section 32 of the first photodetector 11 is electrically connected to the gate electrode 22B of the second photodetector 12 by wiring formed entirely within the detection region 10. However, the entire wiring connecting the output section 32 and the second photodetector 12 does not necessarily have to be formed within the detection region 10. For example, the wiring connected to the output section 32 may be electrically connected to the gate electrode 22B of the second photodetector 12 via wiring formed in another detection region 10.

[0036] The gate electrode 22B of the second photodetector 12 has a split-gate structure, and the gate electrode 22B has two portions 22aB, 22aB. The first output signal, output from the output unit 32 and inverted by the inverting element 33, is input to one portion 22aB. The first output signal, output from the output unit 32, is input to the other portion 22aB. Therefore, the voltage applied to one portion 22aB is expressed as V4 = -V3, and the voltage applied to the other portion 22aB is expressed as V3. The current flowing through the drain electrode 25B of the second photodetector 12 is output from the second photodetector 12 as a second output signal (current signal) Iout. In this example, no voltage is applied to the drain electrode 25B. In this example, since a PN junction is formed by the split-gate structure, the second output signal can be output even without applying a voltage to the drain electrode 25B. On the other hand, a voltage may be applied to the drain electrode 25B. In this case, similar to the case of the first light-receiving element 11, the resistor and voltage application unit are electrically connected to the drain electrode 25B of the second light-receiving element 12.

[0037] As described above, the second photodetector 12 has a phototransistor structure 50, and in the second photodetector 12, a current flows between the source electrode 24B and the drain electrode 25B in accordance with the intensity of light incident on the photoelectric conversion unit 26B, with a gain corresponding to the magnitude of the voltage applied to the gate electrode 22B. In the example shown in Figure 4, the first output signal (voltage V3) output from the output unit 32 of the first photodetector 11 is applied to the gate electrode 22B of the second photodetector 12, and the gain of the second photodetector 12 changes in accordance with the first output signal.

[0038] Figure 5(a) is a diagram illustrating the operation of the array sensor 1 when the intensity of the incident light (ambient light) is weak, and Figure 5(b) is a diagram illustrating the operation of the array sensor 1 when the intensity of the incident light is strong. As shown in Figure 5(a), when the intensity of the incident light is low, current does not easily flow between the source electrode 24A and the drain electrode 25A in the first photodetector 11, and the voltage V3, which is the first output signal, becomes approximately equal to the voltage V1 applied by the voltage application unit VA.

[0039] As shown in Figure 5(b), when the intensity of incident light is high, a current flows between the source electrode 24A and the drain electrode 25A of the first photodetector 11. If the current flowing through the resistor 31 is Ip, the voltage V3, which is the first output signal, becomes (V1 - R × Ip), and the voltage V3 decreases by the amount of the voltage drop across the resistor 31. As a result, the voltage V3 applied to the gate electrode 22B of the second photodetector 12 also decreases, and the gain (sensitivity) of the second photodetector 12 decreases. In this way, the array sensor 1 can maintain a relatively high gain of the second photodetector 12 when the intensity of incident light is low, while decreasing the gain of the second photodetector 12 when the intensity of incident light is high, thus adjusting the gain according to the intensity of ambient light.

[0040] Furthermore, in the array sensor 1, the first light-receiving element 11 also has a phototransistor structure 50, and in the first light-receiving element 11, a current flows between the source electrode 24A and the drain electrode 25A according to the intensity of light incident on the photoelectric conversion unit 26A, with a gain corresponding to the magnitude of the voltage applied to the gate electrode 22A. Therefore, the gain of the first light-receiving element 11 can be adjusted, for example, by adjusting the voltage applied to the gate electrode 22A. This makes it possible to adjust the gain of the first light-receiving element 11 according to the operating environment of the array sensor 1 (e.g., outdoors / indoors).

[0041] In the array sensor 1, a second output signal Iout from the second photodetector 12 is output from each detection region 10. The signals output from each detection region 10 are processed, for example, as the signals of the corresponding pixels in the output image. Thus, in this example, the signals output from each detection region 10 are based solely on the second output signal from the second photodetector 12 and not on the first output signal from the first photodetector 11. In other words, as in the modified example described later, no process is performed to calculate the signals output from each detection region 10 by adding the first output signal to the second output signal. [Operation and Effects]

[0042] In the array sensor 1, since the second light-receiving element 12 has the phototransistor structure 50, the gain of the second light-receiving element 12 can be adjusted by adjusting the voltage applied to the gate electrode 22 of the second light-receiving element 12. More specifically, the first light-receiving element 11 and the second light-receiving element 12 are arranged in each detection region 10. In each detection region 10, the output portion 32 of the first light-receiving element 11 is electrically connected to the gate electrode 22 of the second light-receiving element 12, and the gain of the second light-receiving element 12 changes according to the first output signal output from the output portion 32 of the first light-receiving element 11. As a result, the gain of the second light-receiving element 12 is adjusted according to the intensity of the ambient light incident on the first light-receiving element 11 for each detection region 10. As a result, even when the intensity of the ambient light incident on each detection region 10 is different, for example, different gains can be set for each detection region 10 according to the intensity of the ambient light. Therefore, the operation of the array sensor 1 can be adjusted according to the intensity of the ambient light, and the output can be stabilized. Further, in the array sensor 1, in each detection region 10, the output portion 32 of the first light-receiving element 11 is electrically connected to the gate electrode 22 of the second light-receiving element 12. As a result, for example, compared with the case where the output from the first light-receiving element 11 is output to an external circuit and processed in the external circuit, the power for driving the external circuit becomes unnecessary, and the power consumption can be reduced. Further, compared with the case, the wiring length can be shortened, and the generation of noise can be suppressed. Further, compared with the case, the array sensor 1 can be miniaturized. From the above, according to the array sensor 1, an operation adapted to the ambient light is possible, and reduction of power consumption and suppression of noise are possible.

[0043] Each detection region 10 has only one first light-receiving element 11 and one second light-receiving element 12. As a result, it is possible to configure one detection region 10 to be small, increase the number of detection regions 10 per unit area, and perform an operation adapted to the ambient light for smaller regions.

[0044] The photoelectric conversion unit 26 of the second light-receiving element 12 includes a two-dimensional layer material 27 electrically connected to the source electrode 24 and the drain electrode 25. Thereby, the characteristics such as the bandgap of the second light-receiving element 12 can be adjusted by selecting atoms and layer configurations in the two-dimensional layer material 27, and a desired optical response can be obtained.

[0045] The first light-receiving element 11 has a phototransistor structure 50 including a gate electrode 22, a source electrode 24, a drain electrode 25, and a photoelectric conversion unit 26. Thereby, the gain of the first light-receiving element 11 can be adjusted by adjusting the voltage applied to the gate electrode 22 of the first light-receiving element 11. Thereby, for example, it is possible to adjust the gain of the first light-receiving element 11 according to the usage environment (for example, outdoors / indoors) of the array sensor 1.

[0046] The photoelectric conversion unit 26 of the first light-receiving element 11 includes a two-dimensional layer material 27 electrically connected to the source electrode 24 and the drain electrode 25. Thereby, the characteristics such as the bandgap of the first light-receiving element 11 can be adjusted by selecting atoms and layer configurations in the two-dimensional layer material 27, and a desired optical response can be obtained.

[0047] The signal output from each detection region 10 is based on the second output signal from the second light-receiving element 12 and not on the first output signal from the first light-receiving element 11. Thereby, only the second output signal from the second light-receiving element 12 corresponding to the intensity of ambient light can be reflected in the output.

[0048] In each detection region 10, the light-receiving area (total light-receiving area) of the second light-receiving element 12 is larger than the light-receiving area (total light-receiving area) of the first light-receiving element 11. Thereby, the second output signal from the second light-receiving element 12 corresponding to the intensity of ambient light can be increased.

[0049] The gate electrode 22 of the second light-receiving element 12 has a pair of portions 22a, 22a separated from each other. Thereby, the gain is likely to change linearly with respect to the voltage applied to the gate electrode 22, and the phototransistor structure 50 of the second light-receiving element 12 can be preferably configured. [Modification example]

[0050] The first photodetector 11 may be configured as shown in Figures 6(a) to 6(c). In the example of Figure 4, the first photodetector 11 had a structure in which a resistor 31 was combined with a single-gate photodetector portion 13, whereas in the example of Figure 6(a), the first photodetector 11 has a structure in which two single-gate photodetector portions 13 are combined (connected). In the example of Figure 6(a), the output portion 32 corresponds to the source electrode in the upper photodetector portion 13 and the drain electrode in the lower photodetector portion 13. In this case as well, the first photodetector 11 is configured to have a phototransistor structure.

[0051] In the example shown in Figure 6(b), the first light-receiving element 11 includes a photodiode 34. In this example, a resistor 35 is provided downstream of the photodiode 34, and the portion of the first light-receiving element 11 between the photodiode 34 and the resistor 35 constitutes the output portion 32 of the first light-receiving element 11. In this case, the first light-receiving element 11 does not have a phototransistor structure, but outputs a first output signal from the output portion 32 corresponding to the intensity of incident light. In this case, the first light-receiving element 11 has an anode 41 and a ground portion 42. In the example shown in Figure 6(c), the first light-receiving element 11 is configured as a split-gate structure, and the gate electrode 22A has two portions 22aA, 22aA. In the example shown in Figure 6(c), the portion of the output portion 32 corresponds to the source electrode 24A of the first light-receiving element 11. Thus, the first light-receiving element 11 may have the structure of the light-receiving element portion 13 shown in Figure 3(a). Alternatively, the first light-receiving element 11 may have the structure of the light-receiving element section 13 shown in Figure 2(b), Figure 3(b), or Figure 3(c).

[0052] The second photodetector 12 may be configured as shown in Figures 7(a) to 7(c). In the example of Figure 4, a voltage of V4 = -V3 was applied to one portion 22aB of the gate electrode 22B, whereas in the example of Figure 7(a), a fixed voltage V4 is applied to one portion 22aB. In the example of Figure 7(b), a first output signal from one first photodetector 11 is input to one portion 22aB, and a first output signal from another first photodetector 11 is input to the other portion 22aB. This configuration can be used when two or more first photodetectors 11 are arranged in one detection region 10, as shown in the modified example of Figure 8 described later. In the example of Figure 7(b), the first output signal from one first photodetector 11 and the first output signal from another first photodetector 11 are configured to have opposite polarities. Furthermore, it is sufficient that a potential difference exists between the two parts 22aB, 22aB, and a voltage of the same polarity may be applied to parts 22aB, 22aB.

[0053] In the example shown in Figure 7(c), the second photodetector 12 is configured as a single-gate structure. Thus, the second photodetector 12 may have the structure of the photodetector section 13 shown in Figure 2(a). Alternatively, the second photodetector 12 may have the structure of the photodetector section 13 shown in Figure 2(b), Figure 3(b), or Figure 3(c). When the second photodetector 12 is configured as shown in Figures 7(a) to 7(c), compared to when the second photodetector 12 is configured as shown in Figure 4, an inversion circuit is not required, which reduces power consumption and allows for miniaturization.

[0054] In the modified example shown in Figure 8, each detection region 10 has two first photodetectors 11 and one second photodetector 12. In this example, the gain of the second photodetector 12 changes in response to the first output signals output from the two first photodetectors 11. More specifically, as in the example of Figure 7(b) described above, the first output signal from one of the first photodetectors 11 is input to one of the pair of portions 22aB, 22aB of the gate electrode 22B of the second photodetector 12, and the first output signal from the other first photodetector 11 is input to the other of the pair of portions 22aB, 22aB. The two first photodetectors 11 may have different gains (sensitivity). For example, the gains of the two first photodetectors 11 can be adjusted to be different from each other by adjusting the voltage applied to the gate electrode 22A of the two first photodetectors 11. As another example, in the example of Figure 4 described above, a plurality of first light-receiving elements 11 may be formed in one detection region 10, and the first output signals from the plurality of first light-receiving elements 11 may be combined and input to the second light-receiving element 12. In this case, the second light-receiving element 12 may have an inversion element 33.

[0055] Even with these modifications, operation adapted to ambient light is possible, as in the above embodiment, while reducing power consumption and suppressing noise. Furthermore, each detection region 10 includes two first photodetectors 11 having different gains (sensitivity). This makes it possible to widen the dynamic range compared to, for example, the case where only one first photodetector 11 is provided. In addition, when the second photodetector 12 has a split-gate gate electrode 22B, it is possible to input different voltage values ​​to a pair of portions 22aB, 22aB of the gate electrode 22B.

[0056] In the modified example shown in Figure 9, each detection region 10 has two first photodetectors 11 and two second photodetectors 12. In this example, the gain of one second photodetector 12 changes in response to a first output signal output from one first photodetector 11, and the gain of the other second photodetector 12 changes in response to a first output signal output from the other first photodetector 11. In each detection region 10, the signals from the two second photodetectors 12 are combined and output as an output signal. In this example, the outputs of the two second photodetectors 12 are connected by wiring, and the output signals from one second photodetector 12 are added together while the output signal from the other second photodetector 12 is subtracted, resulting in the sum of the signals from the two second photodetectors 12. The two second photodetectors 12 have different time response characteristics. In this example, the two second photodetectors 12 have different time response characteristics because voltages of different magnitudes are applied to the gate electrodes 22. In the photodetector section having a phototransistor structure 50, the time response characteristics can be changed by changing the magnitude of the voltage applied to the gate electrode 22.

[0057] Hereinafter, one of the two second photodetectors 12 will be referred to as second photodetector 12A, and the other as second photodetector 12B. Figure 10(a) is a graph showing an example of the time response characteristics of second photodetector 12A, and Figure 10(b) is a graph showing an example of the time response characteristics of second photodetector 12B. In each graph, the output from second photodetectors 12A and 12B is shown as black dots, the intensity of light incident on second photodetectors 12A and 12B is shown as white dots, and the time period during which light is incident is shown as hatching. These points are the same in Figures 11 to 13. In the example shown in Figure 10, the time response characteristics of second photodetectors 12A and 12B are different because their gate voltages are different. In the example shown in Figure 10, the response of second photodetector 12A is faster than the response of second photodetector 12B. When light is incident, the output of the second photodetector 12A increases sharply, while the output of the second photodetector 12B increases more gradually than that of the second photodetector 12A. Furthermore, when light stops being incident, the output of the second photodetector 12A decreases sharply, while the output of the second photodetector 12B decreases more gradually than that of the second photodetector 12A.

[0058] Figure 11(a) shows the output signal from the detection region 10 obtained by combining the signals from the second photodetector 12A and the second photodetector 12B shown in Figures 10(a) and 10(b) (by subtracting the output of the second photodetector 12B from the output of the second photodetector 12A). Figure 11(b) shows the frequency response characteristics of the detection region 10 in this case. As shown in Figure 11(b), in this example, the detection region 10 can be configured to have high response characteristics in a specific frequency band, thereby realizing the function of a frequency bandpass filter. That is, it can realize the function of a time filter that extracts specific temporal changes. In this example, the bandpass filter function of the detection region 10 is realized by combining the second photodetectors 12A and 12B, which function as lowpass filters individually, and subtracting the output of the second photodetector 12B from the output of the second photodetector 12A. More specifically, a bandpass filter function is achieved by using a second photodetector 12A having high response characteristics in a higher frequency band and a second photodetector 12B having high response characteristics in a lower frequency band, and by combining low-pass filters with different characteristics.

[0059] Figures 12 and 13 are diagrams or graphs illustrating another example. In this example as well, the time response characteristics of the second photodetectors 12A and 12B differ because their gate voltages are different. As shown in Figure 12, the response of the second photodetector 12A is faster than the response of the second photodetector 12B. As shown in Figure 13(b), in this example, the response peak is located in a higher frequency band than in Figures 10 and 11. In this way, the characteristics of the time filter can be changed by adjusting the gate voltage to adjust the time response characteristics of the second photodetectors 12A and 12B.

[0060] In the above modified example, the two second photodetectors 12 have the same configuration, and the time response characteristics of the two second photodetectors 12 differ because voltages of different magnitudes are applied to the gate electrodes 22 of the two second photodetectors 12. However, the time response characteristics of the two second photodetectors 12 may differ because the structures of the photoelectric conversion sections 26 of the two second photodetectors 12 are different. In this case, the gate voltages applied to the gate electrodes 22 of the two second photodetectors 12 may be the same or different.

[0061] For example, the number of layers of the two-dimensional layered material 27 in the photoelectric conversion section 26 of the two second light-receiving elements 12 may be different from each other. For instance, the photoelectric conversion section 26 of one second light-receiving element 12 may have one layer of the two-dimensional layered material 27, while the photoelectric conversion section 26 of the other second light-receiving element 12 may have three layers of the two-dimensional layered material 27. By making the number of layers of the two-dimensional layered material 27 in the photoelectric conversion section 26 of the two second light-receiving elements 12 different in this way, the time response characteristics of the two second light-receiving elements 12 can be made different.

[0062] Alternatively, or in addition to the above, the materials of the two-dimensional layered material 27 of the photoelectric conversion section 26 in the two second photodetectors 12 may be different from each other. By using different materials for the two-dimensional layered material 27 of the photoelectric conversion section 26 in the two second photodetectors 12, the time response characteristics of the two second photodetectors 12 can also be made different.

[0063] The structures of the photoelectric conversion sections 26 of the two second photodetectors 12 may be made different from each other by means other than varying the number of layers or the material of the two-dimensional layered material 27. For example, the time response characteristics of the two second photodetectors 12 can be made different by varying the material of the insulating layer 23 that contacts the two-dimensional layered material 27. Thus, varying the structure of the photoelectric conversion section 26 includes varying the material of the layers that the two-dimensional layered material 27 contacts.

[0064] When the gain of the second photodetector 12 is adjusted according to the amount of light received by the first photodetector 11, it is preferable to make the time response characteristics of the two second photodetectors 12 different by making the structures of the photoelectric conversion unit 26 different from each other. When the time response characteristics of the second photodetector 12 are adjusted by the gate voltage, for example, another wire may be connected between the first photodetector 11 and the second photodetector 12 and a voltage for adjusting the time response characteristics may be applied. When the time response characteristics of the two second photodetectors 12 are made different by making the structures of the photoelectric conversion unit 26 different from each other, each detection region 10 may have only one first photodetector 11. In the configuration of Figure 9, it is also possible to realize the function of a spatial filter, such as a Gaussian filter, by connecting the two second photodetectors 12 together, in addition to a time filter.

[0065] The first photodetector 11 and the second photodetector 12 may be arranged as shown in Figures 14(a) to 14(c) or Figures 15(a) to 15(d). In the example of Figure 4 described above, one first photodetector 11 and one second photodetector 12 were arranged in each detection region 10. In this case, the responsiveness can be adjusted for each detection region 10. In the example of Figure 14(a), two first photodetectors 11 and one second photodetector 12 are arranged in each detection region 10, similar to the cases of Figures 7(b) and 8. In this case, the dynamic range of the first photodetector 11 can be artificially widened, making it possible to respond appropriately to ambient light. In the example of Figure 14(b), one first photodetector 11 and four second photodetectors 12 are arranged in each detection region 10. In this case, by adjusting the gain of multiple second photodetectors 12 together, it is possible to suppress an excessive decrease in contrast. Furthermore, by connecting the second photodetectors 12 together, a time filter function can be realized.

[0066] In the example shown in Figure 14(c), two first photodetectors 11 and four second photodetectors 12 are arranged in each detection region 10. In this case, the dynamic range of the first photodetectors 11 can be artificially widened, making it possible to respond appropriately to ambient light. Furthermore, by adjusting the gain of multiple second photodetectors 12 together, it is possible to suppress excessive reduction in contrast, and by connecting the second photodetectors 12 to each other, a time filter function can be realized.

[0067] In the example shown in Figure 15(a), one first photodetector 11 and one second photodetector 12 are arranged in each detection region 10. In this case, the responsiveness can be adjusted for each detection region 10. In the example shown in Figure 15(b), two first photodetectors 11 and one second photodetector 12 are arranged in each detection region 10. In this case, the dynamic range of the first photodetector 11 can be artificially widened, making it possible to respond appropriately to ambient light. In the example shown in Figure 15(c), one first photodetector 11 and four second photodetectors 12 are arranged in each detection region 10. In this case, by adjusting the gain of multiple second photodetectors 12 together, it is possible to suppress an excessive decrease in contrast. Furthermore, by connecting the second photodetectors 12 together, a time filter function can be realized.

[0068] In the example shown in Figure 15(d), two first photodetectors 11 and four second photodetectors 12 are arranged in each detection region 10. In this case, the dynamic range of the first photodetectors 11 can be artificially widened, making it possible to respond appropriately to ambient light. Furthermore, by adjusting the gain of multiple second photodetectors 12 together, it is possible to suppress an excessive decrease in contrast, and by connecting the second photodetectors 12 to each other, a time filter function can be realized.

[0069] In the examples shown in Figures 14(a) to 14(c), in each detection region 10, the area of ​​the light-receiving surface of each first light-receiving element 11 is smaller than the area of ​​the light-receiving surface of each second light-receiving element 12. In each detection region 10, the total area of ​​the light-receiving surface of the second light-receiving element 12 is larger than the total area of ​​the light-receiving surface of the first light-receiving element 11. "Total area of ​​the light-receiving surface of the first light-receiving element 11" refers to the area of ​​the light-receiving surface of one first light-receiving element 11 if one first light-receiving element 11 is provided, and the sum of the areas of the light-receiving surfaces of those two or more first light-receiving elements 11 if two or more first light-receiving elements 11 are provided. The same applies to the total area of ​​the light-receiving surface of the second light-receiving element 12. In this way, when the total area of ​​the light-receiving surface of the second light-receiving element 12 is larger than the total area of ​​the light-receiving surface of the first light-receiving element 11 in each detection region 10, the second output signal from the second light-receiving element 12, corresponding to the intensity of ambient light, can be increased.

[0070] In the examples shown in Figures 15(a) to 15(d), in each detection region 10, the area of ​​the light-receiving surface of each first light-receiving element 11 is larger than the area of ​​the light-receiving surface of each second light-receiving element 12. In each detection region 10, the total area of ​​the light-receiving surface of the first light-receiving element 11 is larger than the total area of ​​the light-receiving surface of the second light-receiving element 12. When the area of ​​the light-receiving surface of each first light-receiving element 11 is larger than the area of ​​the light-receiving surface of each second light-receiving element 12 in each detection region 10, the area of ​​the light-receiving surface of the first light-receiving element 11 can be secured, and the sensitivity to changes in ambient light can be improved.

[0071] Each detection region 10 may contain a plurality of first light-receiving elements 11 and / or a plurality of second light-receiving elements 12 of different sizes. In this case, in each detection region 10, the area of ​​the light-receiving surface of any of the first light-receiving elements 11 may be larger than the area of ​​the light-receiving surface of any of the second light-receiving elements 12. In other words, the area of ​​the light-receiving surface of the first light-receiving element 11 with the largest light-receiving surface may be larger than the area of ​​the light-receiving surface of the second light-receiving element 12 with the smallest light-receiving surface. Even in this case, the area of ​​the light-receiving surface of the first light-receiving element 11 can be secured, and the sensitivity to changes in ambient light can be improved. The arrangement, number, and shape of the first light-receiving elements 11 and second light-receiving elements 12 in each detection region 10 are not limited to the above example, and may be arranged, numbered, and shaped in any way. For example, the light-receiving surfaces of the first light-receiving elements 11 and second light-receiving elements 12 may have the same shape.

[0072] In the above embodiment, the signals output from each detection region 10 were based only on the second output signal from the second photodetector 12 and not on the first output signal from the first photodetector 11. However, the signals output from each detection region 10 may be based on both the first output signal from the first photodetector 11 and the second output signal from the second photodetector 12. For example, the signal output from each detection region 10 may be calculated by adding the first output signal to the second output signal. In this case, the first output signal from the first photodetector 11 can be reflected in the output in addition to the second output signal from the second photodetector 12, which corresponds to the intensity of ambient light. This makes effective use of the first output signal from the first photodetector 11. However, in this case, in order to reliably perform correction according to the intensity of ambient light, it is preferable to make the total area of ​​the light-receiving surface of the second photodetector 12 larger than the total area of ​​the light-receiving surface of the first photodetector 11 in each detection region 10. This is because, in the signal obtained by summing the first output signal and the second output signal, it is possible to ensure that the proportion of the second output signal, which has been corrected according to the intensity of ambient light, is maintained. In the above embodiment, in addition to the second output signal from the second photodetector 12, a first output signal from the first photodetector 11 may also be output (separately from the second output signal). In this case, for example, it becomes possible to monitor the voltage V3 applied to the gate electrode 22B of the second photodetector 12 based on the first output signal.

[0073] In the modified example shown in Figure 16, each detection region 10 has one first light-receiving element 11 and two second light-receiving elements 12, and a second output signal is output from each of the two second light-receiving elements 12 in each detection region 10. In this case, each of the two second light-receiving elements 12 arranged in each detection region 10 corresponds to a pixel of an image formed based on the output signal from the image sensor. That is, in this case, multiple (two in this example) pixels are formed based on the detection result in one detection region 10. Thus, the detection region 10 and pixels do not necessarily have to correspond one-to-one, and one detection region 10 may correspond to multiple pixels.

[0074] In the modified example shown in Figure 17, the plurality of detection regions 10 include a rectangular detection region 10A and a rectangular annular detection region 10B surrounding the detection region 10A. Two first photodetectors 11 and four second photodetectors 12 are arranged in the detection region 10A. Four first photodetectors 11 and twelve second photodetectors 12 are arranged in the detection region 10B. Although only one pair of detection regions 10A, 10B is shown in Figure 17, in reality, for example, pairs of detection regions 10A, 10B may be arranged in a grid. Thus, the plurality of detection regions 10 may include an innerly arranged detection region 10A and an outerly arranged detection region 10B. In this case, the gain of the second photodetectors 12 can be adjusted in each of the inner detection region 10A and the outer detection region 10B.

[0075] As shown in the modified examples in Figures 18(a) and 18(b), the multiple detection regions 10 may have overlapping portions. In the example in Figure 18(a), the multiple detection regions 10 include two detection regions 10C and 10D. Each of the detection regions 10C and 10D has one first photodetector 11 and two second photodetectors 12. Detection region 10C extends along direction D3, and detection region 10D extends along direction D4 perpendicular to direction D3. Detection regions 10C and 10D overlap in their central portions. Although only one pair of detection regions 10C and 10D is shown in Figure 18(a), in reality, for example, pairs of detection regions 10C and 10D may be arranged in a grid pattern. Thus, the multiple detection regions 10 may include detection regions 10C and 10D that have overlapping portions. In this case, the degree of freedom in arranging the detection regions 10 can be improved.

[0076] In the example shown in Figure 18(b), multiple detection regions 10 are arranged along direction D5, and adjacent detection regions 10 in direction D5 have overlapping portions. Each detection region 10 is equipped with one first photodetector 11 and one second photodetector 12. One portion of direction D5 in one detection region 10 overlaps with the other portion of direction D5 in an adjacent detection region 10 on that same side. The other portion of direction D5 in one detection region 10 overlaps with the one portion of direction D5 in an adjacent detection region 10 on that other side. In this case as well, the degree of freedom in arranging the detection regions 10 can be improved. Although only one row of detection regions 10 arranged along direction D5 is shown in Figure 18(b), in reality, for example, rows of detection regions 10 may also be arranged in a direction perpendicular to direction D5.

[0077] Thus, the multiple detection regions 10 may have overlapping portions. The detection region 10 is a region in which at least one first photodetector 11 and at least one second photodetector 12 whose gain changes in accordance with a first output signal output from the at least one first photodetector 11 are arranged.

[0078] This disclosure is not limited to the embodiments and modifications described above. For example, the materials and shapes of each component are not limited to those described above, but can be made from a variety of materials and shapes. In the embodiments described above, the array sensor 1 had a plurality of detection regions 10 arranged in two dimensions, but the array sensor 1 may have only a plurality of detection regions 10 arranged in one dimension (in a single row).

[0079] When the first light-receiving element 11 has a phototransistor structure 50, the photoelectric conversion portion 26 of the phototransistor structure 50 does not necessarily have to include a two-dimensional layered material 27. Similarly, the photoelectric conversion portion 26 of the phototransistor structure 50 in the second light-receiving element 12 does not necessarily have to include a two-dimensional layered material 27. For example, instead of the two-dimensional layered material 27, a phototransistor in which the photoelectric conversion portion is formed by electrostatic doping of silicon may be used.

[0080] 1...array sensor, 10...detection region, 11...first photodetector, 12, 12A, 12B...second photodetector, 22, 22A, 22B...gate electrode, 22a, 22aA, 22aB...part, 24, 24A, 24B...source electrode, 25, 25A, 25B...drain electrode, 26, 26A, 26B...photoelectric conversion section, 27...two-dimensional layered material, 32...output section, 50...phototransistor structure.

Claims

1. The device comprises a plurality of first light-receiving elements and a plurality of second light-receiving elements, wherein at least one first light-receiving element from the plurality of first light-receiving elements and at least one second light-receiving element from the plurality of second light-receiving elements are arranged in each of a plurality of detection regions arranged in one or two dimensions, each of the plurality of first light-receiving elements outputs a first output signal from an output unit corresponding to the intensity of incident light, and each of the plurality of second light-receiving elements has a phototransistor structure including a gate electrode, a source electrode, a drain electrode, and a photoelectric conversion unit, and in each of the plurality of second light-receiving elements, a current flows between the source electrode and the drain electrode in accordance with the intensity of light incident on the photoelectric conversion unit, with a gain corresponding to the voltage applied to the gate electrode. An array sensor wherein, in each of the plurality of detection regions, the output section of the at least one first photodetector is electrically connected to the gate electrode of the at least one second photodetector, the gain of the at least one second photodetector changes in response to the first output signal output from the output section of the at least one first photodetector, and a signal is output from each of the plurality of detection regions, at least based on the second output signal from the at least one second photodetector.

2. The array sensor according to claim 1, wherein the at least one first light-receiving element consists of one first light-receiving element, and the at least one second light-receiving element consists of one second light-receiving element.

3. The array sensor according to claim 1, wherein the at least one first light-receiving element includes two or more first light-receiving elements having different sensitivities from each other.

4. The array sensor according to any one of claims 1 to 3, wherein the at least one second photodetector includes two or more second photodetectors having different time response characteristics.

5. The array sensor according to any one of claims 1 to 4, wherein the photoelectric conversion unit of each of the plurality of second photodetectors includes a two-dimensional layered material electrically connected to the source electrode and the drain electrode.

6. The array sensor according to any one of claims 1 to 5, wherein each of the plurality of first light-receiving elements has a phototransistor structure including a gate electrode, a source electrode, a drain electrode, and a photoelectric conversion unit.

7. The array sensor according to claim 6, wherein each of the plurality of first light-receiving elements includes a two-dimensional layered material electrically connected to the source electrode and the drain electrode.

8. The array sensor according to any one of claims 1 to 7, wherein the signal output from each of the plurality of detection regions is based on the second output signal from the at least one second photodetector and not on the first output signal from the at least one first photodetector.

9. The array sensor according to any one of claims 1 to 7, wherein the signal output from each of the plurality of detection regions is based on the first output signal from the at least one first photodetector and the second output signal from the at least one second photodetector.

10. The array sensor according to any one of claims 1 to 9, wherein in each of the plurality of detection regions, the total area of ​​the light-receiving surfaces of at least one second light-receiving element is greater than the total area of ​​the light-receiving surfaces of at least one first light-receiving element.

11. The array sensor according to any one of claims 1 to 10, wherein in each of the plurality of detection regions, the area of ​​the light-receiving surface of any one of the at least one first light-receiving element is larger than the area of ​​the light-receiving surface of any one of the at least one second light-receiving element.

12. The array sensor according to any one of claims 1 to 11, wherein the gate electrode of each of the plurality of second photodetectors has a pair of portions spaced apart from each other.

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