Detection device

Abstract

The detection device includes: a substrate; and a photodiode in which a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode are laminated in this order on the substrate. The lower electrode extends from a region overlapping the organic semiconductor layer including the lower buffer layer, the active layer, and the upper buffer layer to a region outside a side surface of the organic semiconductor layer. Furthermore, the detection device has a plurality of photodiodes, the plurality of lower electrodes are arranged so as to correspond to the plurality of photodiodes, and extend to a region further outward than at least a side surface of the organic semiconductor layer in the first direction, and the plurality of photodiodes are arranged in a second direction intersecting the first direction, and extend to a region further outward than the side surface of the organic semiconductor layer in the second direction. The upper electrode extends in the second direction across the plurality of photodiodes.

Description

Technical Field

[0001] The invention relates to a detection device. Background Art

[0002] There are known optical sensors that can detect fingerprint patterns and vein patterns (e.g., Patent Document 1). Such optical sensors have a plurality of photodiodes using organic semiconductor materials as active layers. As described in Patent Document 2, the photodiodes are arranged between the lower electrode and the upper electrode, for example, in the order of the lower electrode, the electron transport layer, the active layer, the hole transport layer, and the upper electrode. The electron transport layer or the hole transport layer is also called a buffer layer.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-32005

[0006] Patent Document 2: International Publication No. 2020 / 188959 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] Sometimes the organic semiconductor layer including the electron transport layer, the active layer and the hole transport layer is set to have an area larger than the lower electrode. The photocarriers generated in the portion of the organic semiconductor layer that does not overlap with the lower electrode arrive at the lower electrode later than the photocarriers generated in the portion of the organic semiconductor layer that overlaps with the lower electrode. As a result, the photocarriers generated in the portion of the organic semiconductor layer that does not overlap with the lower electrode cannot be fully read out, and the detection accuracy may decrease. Alternatively, in order to also read out the photocarriers generated in the portion of the organic semiconductor layer that does not overlap with the lower electrode, the readout period becomes longer and the detection speed may decrease.

[0009] An object of the present invention is to provide a detection device capable of improving detection accuracy.

[0010] Solutions for solving technical problems

[0011] A detection device according to one aspect of the present invention comprises: a substrate; and a photodiode, wherein the photodiode is stacked on the substrate in the order of a lower electrode, a lower buffer layer, an active layer, an upper buffer layer and an upper electrode, and when observed from above, the lower electrode extends from an area overlapping with an organic semiconductor layer including the lower buffer layer, the active layer and the upper buffer layer to an area further outward than a side surface of the organic semiconductor layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1It is a top view showing the detection device according to the first embodiment.

[0013] Figure 2 1 is a circuit diagram showing a detection device according to the first embodiment.

[0014] Figure 3 for Figure 1 III-III' cross-sectional view.

[0015] Figure 4 It is a top view schematically showing the connection structure between the upper electrode and the terminal portion.

[0016] Figure 5 for Figure 4 V-V' cross-sectional view.

[0017] Figure 6 It is a top view showing a detection device according to the second embodiment.

[0018] Figure 7 1 is a circuit diagram showing a detection device according to a second embodiment.

[0019] Figure 8 The figure is a plan view showing four photodiodes arranged at the corners of the detection area in an enlarged manner.

[0020] Fig. 9 for Figure 8 IX-IX' section view.

[0021] Fig.10 for Figure 6 X-X' cross-sectional view. DETAILED DESCRIPTION

[0022] The mode (implementation method) for implementing the present invention is described in detail with reference to the accompanying drawings. The present disclosure is not limited to the contents described in the following implementation methods. In addition, the constituent elements described below include elements that can be easily thought of by a person skilled in the art, and substantially the same elements. Moreover, the constituent elements described below can be appropriately combined. It should be noted that the disclosure is only an example after all, and suitable changes that can be easily thought of by a person skilled in the art while maintaining the gist of the present disclosure are of course included in the scope of the present disclosure. In addition, in the accompanying drawings, in order to make the description clearer, the width, thickness, shape, etc. of each part are sometimes schematically shown compared to the actual situation, but it is only an example after all, and the interpretation of the present disclosure is not limited. In addition, in the present disclosure and the drawings, for the elements that are the same as the elements described in the figures that have appeared, the same figure mark is sometimes marked, and the detailed description is appropriately omitted.

[0023] In the present specification and claims, when expressing a situation in which other structures are arranged on a certain structure, when it is simply recorded as "on", unless otherwise specified, it includes the following two situations, namely, other structures are arranged directly above the certain structure in a manner of being connected to the certain structure and other structures are arranged above the certain structure with other structures interposed therebetween.

[0024] (First Embodiment)

[0025] Figure 1 It is a top view showing the detection device according to the first embodiment. Figure 2 FIG. 2 is a circuit diagram showing a detection device according to a first embodiment. Figure 1 and Figure 2 As shown, the detection device 1 includes a substrate 21 , a plurality of photodiodes PD, a plurality of signal lines SL, a power supply line CL1 , and a control circuit 122 .

[0026] The substrate 21 has a detection area AA and a peripheral area GA. The detection area AA is an area where a plurality of photodiodes PD are provided. The peripheral area GA is an area between the periphery of the detection area AA and the end of the substrate 21, and is an area where a plurality of photodiodes PD are not provided. A plurality of signal lines SL and a control circuit 122 are provided in the peripheral area GA of the substrate 21.

[0027] It should be noted that, in the following description, the first direction Dx is a direction in a plane parallel to the substrate 21. The second direction Dy is a direction in a plane parallel to the substrate 21, and is a direction orthogonal to the first direction Dx. It should be noted that the second direction Dy may not intersect the first direction Dx orthogonally. The third direction Dz is a direction orthogonal to the first direction Dx and the second direction Dy. The third direction Dz is the normal direction of the substrate 21. In addition, "top view" refers to the positional relationship when observed from a direction perpendicular to the substrate 21.

[0028] The detection device 1 has a plurality of photodiodes PD as light sensor elements. The photodiodes PD output electrical signals corresponding to the irradiated light. More specifically, the photodiodes PD are OPDs (Organic Photodiodes) using organic semiconductors. The plurality of photodiodes PD are arranged side by side in the second direction Dy in the detection area AA.

[0029] like Figure 2 As shown, cathodes (lower electrodes 23) of the plurality of photodiodes PD are connected to the detection circuit 48 via signal lines SL, respectively. Anodes (upper electrodes 24) of the plurality of photodiodes PD are connected to the power supply circuit 123 via a common power supply wiring CL1.

[0030] More specifically, if Figure 1 As shown, the plurality of photodiodes PD include an organic semiconductor layer 30 (a lower buffer layer 32, an active layer 31, an upper buffer layer 33 (see Figure 3 )), a lower electrode 23 disposed at the lower part of the organic semiconductor layer 30, and an upper electrode 24 disposed at the upper part of the organic semiconductor layer 30. The plurality of lower electrodes 23 are respectively provided corresponding to the plurality of photodiodes PD, and are arranged side by side in the second direction Dy in the detection area AA. In addition, the plurality of lower electrodes 23 are separated and arranged in the second direction Dy.

[0031] The organic semiconductor layer 30 and the upper electrode 24 are extended in the second direction Dy across multiple photodiodes PD and are continuously arranged in the detection area AA. The organic semiconductor layer 30 has four side surfaces 30e1, 30e2, 30e3, and 30e4, and is formed into a roughly rectangular shape when viewed from above. The organic semiconductor layer 30 has a side surface 30e1 on one side of the first direction Dx, a side surface 30e2 on the other side of the first direction Dx, a side surface 30e3 on one side of the second direction Dy, and a side surface 30e4 on the other side of the second direction Dy. In the first direction Dx, the side surface 30e2 is located on the side opposite to the side surface 30e1. In addition, in the second direction Dy, the side surface 30e4 is located on the side opposite to the side surface 30e3. It should be noted that the stacked structure of the organic semiconductor layer 30, the lower electrode 23, and the upper electrode 24 in the photodiode PD will be described later. Figure 3 Described in.

[0032] The plurality of signal lines SL are electrically connected to the lower electrodes 23 of the plurality of photodiodes PD, respectively. Figure 1 In the example shown in the figure, a plurality of signal lines SL are formed through an insulating film 27 (see Figure 3 ) are connected to the plurality of lower electrodes 23 respectively.

[0033] The plurality of signal lines SL extend from the connection portion (contact hole CH1) with the lower electrode 23 in the first direction Dx, and then bend in the second direction Dy to extend in the second direction Dy along the arrangement direction of the plurality of photodiodes PD. The portions of the plurality of signal lines SL extending in the second direction Dy are arranged in the first direction Dx. The plurality of signal lines SL are connected to the detection circuit 48 included in the control circuit 122. In other words, the detection circuit 48 is electrically connected to the lower electrodes 23 of the plurality of photodiodes PD via the plurality of signal lines SL.

[0034] In addition, the upper electrode 24 is extended in the second direction Dy over the detection area AA and the peripheral area GA. Figure 1The connection parts 24a and 30a are respectively provided at the outer edge of the detection area AA (lower side in FIG). The connection parts 24a and 30a are extended from the detection area AA to the peripheral area GA side and are electrically connected to the terminal part 25 via the conductive layer 26. The terminal part 25 is electrically connected to the power supply wiring CL1 through the contact hole CH2.

[0035] With such a configuration, upper electrodes 24 of the plurality of photodiodes PD are connected to a power supply circuit 123 of the control circuit 122 via a conductive layer 26, a terminal portion 25, and a power supply line CL1. The power supply circuit 123 supplies a sensor reference voltage COM to upper electrodes 24 of the photodiodes PD.

[0036] The control circuit 122 (detection circuit 48 and power supply circuit 123) is configured to be adjacent to the photodiode PD in the second direction Dy in the peripheral area GA of the substrate 21. The control circuit 122 is a circuit that supplies control signals to the plurality of photodiodes PD and controls the detection operation. The plurality of photodiodes PD output electrical signals corresponding to the light irradiated respectively as detection signals Vdet to the detection circuit 48. In the present embodiment, the detection signals Vdet of the plurality of photodiodes PD are sequentially output to the detection circuit 48 in a time-division manner. In other words, the plurality of signal lines SL are sequentially electrically connected to the detection circuit 48 in a time-division manner. Thus, the detection device 1 detects information related to the object to be detected based on the detection signals Vdet from the plurality of photodiodes PD.

[0037] It should be noted that the control circuit 122 (detection circuit 48 and power circuit 123) is provided on the substrate 21 like the plurality of photodiodes PD, but the present invention is not limited thereto. The control circuit 122 (detection circuit 48 and power circuit 123) may also be provided on another control substrate connected to the substrate 21 via a flexible printed substrate or the like, for example. In addition, the detection circuit 48 and the power circuit 123 may also be formed as separate circuits.

[0038] In addition, although Figure 1 Although not shown in the figure, the detection device 1 may also include one or more light sources. As the light source, for example, an inorganic LED (Light Emitting Diode), an organic EL (OLED: Organic Light Emitting Diode), or the like is used.

[0039] The light emitted from the light source is reflected by the surface of the detected object such as a finger and is incident on a plurality of photodiodes PD. Thus, the detection device 1 can detect fingerprints by detecting the concave and convex shapes of the surface of the finger, etc. Alternatively, the light emitted from the light source can also be reflected from the inside of the finger, etc. or pass through the finger, etc. and be incident on a plurality of photodiodes PD. Thus, the detection device 1 can detect information related to the inside of the finger, etc. and related to the biological body. Examples of information related to the biological body include pulse waves, pulses, and blood vessel images of fingers and palms. That is, the detection device 1 can also be configured as a fingerprint detection device for detecting fingerprints, or a vein detection device for detecting blood vessel patterns of veins, etc.

[0040] Next, the stacked structure of the organic semiconductor layer 30 , the lower electrode 23 , and the upper electrode 24 in the photodiode PD will be described. Figure 3 for Figure 1 III-III' cross-sectional view.

[0041] In the following description, the direction from the substrate 21 toward the sealing film 28 in the direction perpendicular to the surface of the substrate 21 is referred to as “upper side” or simply “upper”. In addition, the direction from the sealing film 28 toward the substrate 21 is referred to as “lower side” or simply “lower”.

[0042] like Figure 3 As shown, the substrate 21 is an insulating substrate, for example, glass or resin material is used. The substrate 21 is not limited to a flat plate, and may have a curved surface. In this case, the substrate 21 may also be a thin film of resin.

[0043] The signal line SL is provided on the substrate 21. The signal line SL is formed of, for example, a metal wiring and is formed of a material having a higher conductivity than the lower electrode 23 of the photodiode PD. A portion of the signal line SL ( Figure 3 The insulating film 27 is a layer provided between the substrate 21 and the lower electrode 23 of the photodiode PD in the third direction Dz (the right end side of the middle signal line SL). The insulating film 27 is provided on the substrate 21 in a manner covering the signal line SL. The insulating film 27 may be an inorganic insulating film or an organic insulating film. In addition, the insulating film 27 may be a single layer or a laminated film.

[0044] The photodiode PD is provided on the insulating film 27. In more detail, the photodiode PD has a lower electrode 23, a lower buffer layer 32, an active layer 31, an upper buffer layer 33, and an upper electrode 24. The photodiode PD is stacked in the order of the lower electrode 23, the lower buffer layer 32 (electron transport layer), the active layer 31, the upper buffer layer 33 (hole transport layer), and the upper electrode 24 in a direction perpendicular to the substrate 21.

[0045] The lower electrode 23 is provided on the insulating film 27 and is electrically connected to the signal line SL through the contact hole CH1 provided in the insulating film 27. The lower electrode 23 is a cathode electrode of the photodiode PD, and is formed of a light-transmitting conductive material such as ITO (Indium Tin Oxide). The detection device 1 of this embodiment is formed as a bottom light receiving type optical sensor, in which light from the object to be detected passes through the substrate 21 and enters the photodiode PD.

[0046] The characteristics of the active layer 31 (e.g., voltage-current characteristics, resistance value) vary according to the irradiated light. An organic material is used as the material of the active layer 31. Specifically, the active layer 31 is a bulk heterostructure in which a p-type organic semiconductor and an n-type fullerene derivative (PCBM) as an n-type organic semiconductor are mixed. For example, C60 (fullerene), PCBM (phenyl C61-butyric acid methyl ster), CuPc (copper phthalocyanine), F16CuPc (perfluorocopper phthalocyanine), rubrene (rubrene: 5,6,11,12-tetraphenyltetracene: 5,6,11,12-tetraphenyltetracene), PDI (derivative of Perylene), etc., which are low molecular weight organic materials, can be used as the active layer 31.

[0047] The active layer 31 can be formed by evaporation (Dry Process) using these low-molecular organic materials. In this case, the active layer 31 can also be, for example, a stacked film of CuPc and F16CuPc or a stacked film of rubrene and C60. The active layer 31 can also be formed by coating (Wet Process). In this case, the active layer 31 uses a material formed by combining the above-mentioned low-molecular organic materials and high-molecular organic materials. For example, P3HT (poly(3-hexylthiophene): poly(3-hexylthiophene)), F8BT (F8-alt-benzothiadiazole: F8-alt-benzothiadiazole), etc. can be used as high-molecular organic materials. The active layer 31 can be set as a film in a state where P3HT and PCBM are mixed or a film in a state where F8BT and PDI are mixed.

[0048] The lower buffer layer 32 is an electron transport layer, and the upper buffer layer 33 is a hole transport layer. The lower buffer layer 32 and the upper buffer layer 33 are provided to facilitate the holes and electrons generated in the active layer 31 to reach the lower electrode 23 or the upper electrode 24. The lower buffer layer 32 (electron transport layer) is directly connected to the lower electrode 23. The active layer 31 is directly connected to the lower buffer layer 32. The material of the electron transport layer uses ethoxylated polyethyleneimine (PEIE).

[0049] The upper buffer layer 33 (hole transport layer) is directly connected to the active layer 31, and the upper electrode 24 is directly connected to the upper buffer layer 33. The hole transport layer is made of an oxidized metal layer. Tungsten trioxide (WO 3 ), molybdenum oxide, etc. as the metal oxide layer.

[0050] It should be noted that the materials and manufacturing methods of the lower buffer layer 32, the active layer 31 and the upper buffer layer 33 are only examples, and other materials and manufacturing methods may also be used. For example, the lower buffer layer 32 and the upper buffer layer 33 are not limited to single-layer films, and may also be formed as a stacked film in a manner including an electron blocking layer and a hole blocking layer.

[0051] The upper electrode 24 is disposed on the upper buffer layer 33. The upper electrode 24 is the anode electrode of the photodiode PD and is continuously formed throughout the entire detection area AA. In other words, the upper electrode 24 is continuously disposed on a plurality of photodiodes PD. The upper electrode 24 is opposed to the plurality of lower electrodes 23 with the lower buffer layer 32, the active layer 31, and the upper buffer layer 33 sandwiched therebetween. The upper electrode 24 is formed of a light-transmitting conductive material such as ITO or IZO.

[0052] The sealing film 28 is provided on the upper electrode 24. The sealing film 28 uses an inorganic film such as a silicon nitride film or an aluminum oxide film or a resin film such as an acrylic film. The sealing film 28 is not limited to a single layer, and may be a laminated film of two or more layers formed by combining the above-mentioned inorganic film and resin film. The sealing film 28 can well seal the photodiode PD and suppress the intrusion of moisture from the upper surface side.

[0053] In the present embodiment, the lower electrode 23 is extended from the region overlapping with the organic semiconductor layer 30 including the lower buffer layer 32, the active layer 31, and the upper buffer layer 33 to the region outside the side surfaces 30e1 and 30e2 of the organic semiconductor layer 30. In more detail, the lower electrode 23 is extended to the region outside the one side surface 30e1 of the organic semiconductor layer 30 in the first direction Dx, and is extended to the region outside the other side surface 30e2 of the organic semiconductor layer 30 in the first direction Dx. That is, the width W2 of the lower electrode 23 in the first direction Dx is greater than the width W1 of the organic semiconductor layer 30 in the first direction Dx. In other words, the lower electrode 23 includes a portion overlapping with the organic semiconductor layer 30 and a portion not overlapping with the organic semiconductor layer 30 in the first direction Dx. In addition, the organic semiconductor layer 30 extends from the one side surface 30e1 in the first direction Dx to the other side surface 30e2 in the first direction Dx, and is overlapped on the lower electrode 23.

[0054] With such a configuration, the organic semiconductor layer 30 does not have a portion that does not overlap with the lower electrode 23 at least in the first direction Dx. Therefore, compared with a configuration in which the organic semiconductor layer 30 is provided to the outside of the outer edge of the lower electrode 23 so as to cover the lower electrode 23, photocarriers generated in the organic semiconductor layer 30 quickly reach the lower electrode 23. Therefore, the detection device 1 can suppress the delay of the light response and improve the detection accuracy.

[0055] In addition, the width W2-L of the portion of the lower electrode 23 extending outward from the side surface 30e1 of the organic semiconductor layer 30 is equal to the width W2-R of the portion extending outward from the side surface 30e2 of the organic semiconductor layer 30 on the side opposite to the first direction Dx. However, this is not limited to this, and the width W2-L may be different from the width W2-R. The lengths of the widths W2-L and W2-R are determined, for example, by a width greater than the positional deviation amount in the coating and patterning process when the organic semiconductor layer 30 is formed.

[0056] exist Figure 3 , the lower electrode 23 is shown to extend to the area outside the side surfaces 30e1 and 30e2 of the organic semiconductor layer 30 in the first direction Dx, but the present invention is not limited to this. Figure 1 As shown, on one side of the second direction Dy ( Figure 1 The upper side of the lower electrode 23 (the lower electrode 23 farthest from the terminal portion 25) arranged on the outermost side extends to an area further outward than the side surfaces 30e1 and 30e2 of the organic semiconductor layer 30 in the first direction Dx, and extends to an area further outward than the side surface 30e3 on one side in the second direction Dy.

[0057] In addition, on the other side of the second direction Dy ( Figure 1 The lower electrode 23 disposed on the outermost side (the lower electrode 23 closest to the terminal portion 25) extends to an area further outward than the side surfaces 30e1 and 30e2 of the organic semiconductor layer 30 in the first direction Dx, and extends to an area further outward than the side surface 30e4 on the other side in the second direction Dy.

[0058] With such a configuration, the side surface 30e3 on one side of the organic semiconductor layer 30 in the second direction Dy and the side surface 30e4 on the other side in the second direction Dy are respectively arranged on the inner side than the outermost periphery of the plurality of lower electrodes 23. Thus, in the photodiodes PD respectively arranged on the outermost sides on one side and the other side in the second direction Dy, the photocarriers generated in the organic semiconductor layer 30 can quickly reach the lower electrode 23, and the light response delay can be suppressed.

[0059] Next, the connection structure between the upper electrodes 24 of the plurality of photodiodes PD, the terminal portion 25 , and the power supply wiring CL1 will be described in detail. Figure 4 It is a top view schematically showing the connection structure between the upper electrode and the terminal portion. Figure 5 for Figure 4 V-V' cross-sectional view.

[0060] like Figure 4 and Figure 5 As shown, the lower electrode 23 of the photodiode PD corresponding to the portion electrically connected to the upper electrode 24 and the power supply wiring CL1 among the plurality of photodiodes PD has a cutout portion 23a. Here, the photodiode PD corresponding to the portion electrically connected to the upper electrode 24 and the power supply wiring CL1 is the photodiode PD arranged on the outermost side on the other side of the second direction Dy among the plurality of photodiodes PD (the photodiode PD closest to the terminal portion 25).

[0061] The cutout portion 23a of the lower electrode 23 is formed to be recessed in a trapezoidal shape from the center of the outer edge portion 23e of the lower electrode 23 toward one side in the second direction Dy. The connection portion 30a of the organic semiconductor layer 30 is arranged to overlap with the cutout portion 23a of the lower electrode 23 and protrude from the side surface 30e4 of the organic semiconductor layer 30 in the second direction Dy. A widening portion of the connection portion 30a in which the width in the first direction Dx gradually increases is provided at the connection position between the side surface 30e4 of the organic semiconductor layer 30 and the connection portion 30a. In addition, the connection portion 24a connected to the upper electrode 24 is provided to overlap with the connection portion 30a of the organic semiconductor layer 30.

[0062] like Figure 5As shown in FIG. 1 , the conductive layer 26 is provided to cover the upper surface of the connection portion 24a of the upper electrode 24 and the side surface of the connection portion 24a of the upper electrode 24 and the side surface of the connection portion 30a of the organic semiconductor layer 30. The conductive layer 26 extends from the side surface of the connection portion 30a along the second direction Dy and is provided to overlap with the terminal portion 25. It should be noted that the connection portion 30a of the organic semiconductor layer 30 and the connection portion 24a of the upper electrode 24 are formed continuously as a whole with the organic semiconductor layer 30 and the upper electrode 24, and have a stacked structure equivalent to the organic semiconductor layer 30 and the upper electrode 24.

[0063] As described above, the terminal portion 25 is electrically connected to the power supply line CL1 through the contact hole CH2 provided in the insulating film 27. With such a configuration, the upper electrode 24 of the photodiode PD is electrically connected to the power supply line CL1 via the conductive layer 26 and the terminal portion 25.

[0064] In this embodiment, the cutout portion 23a is provided in the lower electrode 23, so even when the conductive layer 26 and the outer edge portion 23e of the lower electrode 23 are arranged close to each other, the distance M1 in the second direction Dy between the cutout portion 23a of the lower electrode 23 and the conductive layer 26 can be ensured. Thus, the detection device 1 can achieve a narrow frame while ensuring insulation between the lower electrode 23 and the conductive layer 26.

[0065] It should be noted that Figure 4 and Figure 5 The connection structure of the upper electrode 24, the terminal portion 25, and the power supply line CL1 shown is merely an example and can be modified as appropriate. For example, the cutout portion 23a of the lower electrode 23 may be omitted depending on the characteristics.

[0066] Alternatively, the photodiode PD ( Figure 1 The photodiode PD arranged at the outermost side on the other side of the second direction Dy in the dummy photodiode PD may also be a dummy photodiode. Here, although the dummy photodiode has a stacked structure equivalent to the photodiode PD, it is configured not to function as a photodiode in substance. For example, it can be configured as follows, that is, the signal line SL is not connected to the lower electrode 23 of the dummy photodiode, and the detection signal from the dummy photodiode is not output to the detection circuit 48. Alternatively, it can be configured as follows, that is, the detection circuit 48 does not use the detection signal received from the dummy photodiode to detect information related to the organism.

[0067] It should be noted that, in the first embodiment described above, the detection device 1 is described as having four photodiodes PD. The detection device 1 is not limited thereto, and may also have five or more photodiodes PD. Alternatively, the detection device 1 is not limited to having a plurality of photodiodes PD, and may also have at least one photodiode PD.

[0068] In addition, in the first embodiment described above, an example is shown in which a plurality of photodiodes PD are arranged side by side in the second direction Dy in the detection area AA. However, this is not limited thereto, and a plurality of photodiodes PD may be arranged side by side in the first direction Dx in the detection area AA, or may be arranged side by side in the first direction Dx and the second direction Dy in the detection area AA in a matrix.

[0069] (Second Embodiment)

[0070] Figure 6 It is a top view showing a detection device according to the second embodiment. It should be noted that in the following description, the same reference numerals are given to the same components as those described in the above embodiment to omit repeated descriptions.

[0071] like Figure 6 As shown, the detection device 1A according to the second embodiment further includes a sensor unit 10 including a plurality of photodiodes PD, a plurality of gate lines GL, a plurality of signal lines SL, a gate line driving circuit 15, a signal line selection circuit 16, a first light source substrate 51, a second light source substrate 52, and light sources 53 and 54. A plurality of light sources 53 are provided on the first light source substrate 51. A plurality of light sources 54 are provided on the second light source substrate 52.

[0072] The control substrate 121 is electrically connected to the substrate 21 through the wiring substrate 71. The wiring substrate 71 is, for example, a flexible printed substrate or a rigid substrate. A detection circuit 48 is provided on the wiring substrate 71. A control circuit 122 and a power supply circuit 123 are provided on the control substrate 121. The control circuit 122 supplies a control signal to the gate line drive circuit 15 and the signal line selection circuit 16 to control the detection operation of the sensor unit 10. In addition, the control circuit 122 supplies a control signal to the light sources 53 and 54 to control whether the light sources 53 and 54 are turned on or off. The power supply circuit 123 generates a sensor power supply signal VDDSNS (refer to Figure 7 ) are supplied to the sensor unit 10, the gate line driving circuit 15 and the signal line selecting circuit 16. In addition, the power supply circuit 123 supplies the power supply voltage to the light sources 53 and 54.

[0073] A plurality of light sources 53 are disposed on the first light source substrate 51 and arranged along the second direction Dy. A plurality of light sources 54 are disposed on the second light source substrate 52 and arranged along the second direction Dy. The first light source substrate 51 and the second light source substrate 52 are electrically connected to the control circuit 122 and the power supply circuit 123 through the terminal portions 124 and 125 disposed on the control substrate 121, respectively.

[0074] The multiple light sources 53 and the multiple light sources 54 use, for example, inorganic LEDs (Light Emitting Diodes), organic ELs (OLEDs: Organic Light Emitting Diodes), etc. The multiple light sources 53 and the multiple light sources 54 emit light of different wavelengths, respectively. The detection device 1 is provided with multiple light sources 53 and 54 as light sources. However, it is not limited to this, and the light source may also be one type. For example, multiple light sources 53 and multiple light sources 54 may be respectively arranged on the first light source substrate 51 and the second light source substrate 52. In addition, the light source substrates provided with the light sources 53 and the light sources 54 may also be one or more than three. Alternatively, it is sufficient to configure at least one light source.

[0075] like Figure 6 As shown, in the detection device 1A involved in the second embodiment, a plurality of photodiodes PD are arranged in a matrix in the detection area AA of the substrate 21. A plurality of lower electrodes 23 are respectively provided corresponding to the plurality of photodiodes PD, and are arranged in a matrix in the detection area AA. In other words, the plurality of photodiodes PD (a plurality of lower electrodes 23) are arranged side by side in the first direction Dx and the second direction Dy.

[0076] The organic semiconductor layer 30 and the upper electrode 24 are arranged across a plurality of photodiodes PD and are continuously arranged in the detection area AA. Figure 6 Although the upper electrode 24 is omitted from the figure, the upper electrode 24 is formed in a shape substantially equal to the organic semiconductor layer 30. In the detection device 1A of this embodiment, the lower electrode 23 of the photodiode PD arranged at the outermost periphery is extended to the area outside the side surfaces 30e1, 30e2, 30e3, and 30e4 of the organic semiconductor layer 30 in a plan view. Figure 8 The structure of the outermost lower electrode 23 is described in detail in FIG.

[0077] The gate line driving circuit 15 and the signal line selection circuit 16 are provided in the peripheral area GA. The plurality of gate lines GL extend in the first direction Dx and are connected to the gate line driving circuit 15. The plurality of signal lines SL extend in the second direction Dy and are connected to the signal line selection circuit 16. The plurality of photodiodes PD perform detection according to the gate driving signal supplied from the gate line driving circuit 15. In addition, the plurality of photodiodes PD output electrical signals corresponding to the light irradiated respectively as detection signals Vdet to the signal line selection circuit 16. Thus, the detection device 1A detects information related to the object to be detected based on the detection signals Vdet from the plurality of photodiodes PD.

[0078] In more detail, the gate line driving circuit 15 drives the plurality of gate lines GL row by row. That is, the gate line driving circuit 15 selects the plurality of gate lines GL sequentially or simultaneously, and supplies a gate driving signal to the selected gate line GL. As a result, the driving transistor Tr (refer to FIG. 14 ) connected to the gate line GL becomes turned on (conducting state), and the lower electrodes 23 of the plurality of photodiodes PD connected to the gate line GL are electrically connected to the signal line SL through the driving transistor Tr.

[0079] The signal line selection circuit 16 is a switch circuit that selects a plurality of signal lines SL sequentially or simultaneously. The signal line selection circuit 16 is, for example, a multiplexer. The signal line selection circuit 16 sequentially reads out a plurality of signal lines SL. That is, the signal line selection circuit 16 selects a plurality of signal lines SL based on the control circuit 122 (see Figure 1 ) supplies a selection signal to connect the selected signal line SL and the detection circuit 48.

[0080] Figure 7 FIG. 2 is a circuit diagram showing a detection device according to a second embodiment. Figure 7 In FIG. 4 , the circuit structure of the detection circuit 48 is also shown. Figure 7 As shown, the local detection area PAA includes a photodiode PD, a capacitive element Ca, and a drive transistor Tr. The capacitive element Ca is a capacitor (sensor capacitor) formed in the photodiode PD, and is equivalently connected in parallel with the photodiode PD.

[0081] exist Figure 7 In the figure, two gate lines GL(m) and GL(m+1) are shown in parallel in the second direction Dy among the plurality of gate lines GL. In addition, two signal lines SL(n) and SL(n+1) are shown in parallel in the first direction Dx among the plurality of signal lines SL. The local detection area PAA is an area surrounded by the gate lines GL and the signal lines SL.

[0082] The driving transistor Tr is provided corresponding to each of the plurality of photodiodes PD. The driving transistor Tr is a transistor composed of a thin film transistor, and in this example, is composed of an n-channel MOS (Metal Oxide Semiconductor) type TFT (Thin Film Transistor).

[0083] The plurality of gate lines GL are respectively connected to the gates of the plurality of drive transistors Tr arranged along the first direction Dx. The plurality of signal lines SL are respectively connected to one of the source and drain of the plurality of drive transistors Tr arranged along the second direction Dy. The other of the source and drain of the plurality of drive transistors Tr is connected to the cathode of the photodiode PD and the capacitor element Ca.

[0084] From the power supply circuit 123 (refer to Figure 1 ) supplies a sensor power supply signal VDDSNS to the anode of the photodiode PD. In addition, a sensor reference voltage COM serving as an initial potential of the signal line SL and the capacitor element Ca is supplied from the power supply circuit 123 to the signal line SL and the capacitor element Ca via the reset transistor TrR.

[0085] When light is irradiated to the local detection area PAA during the exposure period, a current corresponding to the amount of light flows to the photodiode PD, thereby accumulating charge in the capacitor element Ca. When the drive transistor Tr is turned on during the readout period, a current flows to the signal line SL according to the charge accumulated in the capacitor element Ca. The signal line SL is connected to the detection circuit 48 via the output transistor TrS of the signal line selection circuit 16. Thus, the detection device 1A can detect a signal corresponding to the amount of light irradiated to the photodiode PD according to the local detection area PAA.

[0086] The detection circuit 48 is connected to the signal line SL by turning on the switch SSW during the readout period. The detection signal amplifier circuit 42 of the detection circuit 48 converts the change of the current supplied from the signal line SL into a change of voltage and amplifies it. A reference potential (Vref) having a fixed potential is input to the non-inverting input part (+) of the detection signal amplifier circuit 42, and the signal line SL is connected to the inverting input part (-). In the embodiment, a signal identical to the sensor reference voltage COM is input as the reference potential (Vref) voltage. The control circuit 122 (refer to Figure 1 ) calculates the difference between the detection signal Vdet when irradiated with light and the detection signal Vdet when not irradiated with light as the sensor output voltage Vo. In addition, the detection signal amplifier circuit 42 has a capacitor element Cb and a reset switch RSW. During the reset period, the reset switch RSW is turned on, and the charge of the capacitor element Cb is reset.

[0087] Figure 8The figure is a plan view showing four photodiodes arranged at the corners of the detection area in an enlarged manner. Figure 8 Four photodiodes PD11 , PD12 , PD13 , and PD14 arranged at corners among the plurality of photodiodes PD in the detection area AA are shown in an enlarged manner.

[0088] The photodiode PD11 is arranged on the central side of the detection area AA, that is, farther from the edge of the detection area AA than the photodiodes PD12, PD13, and PD14. The lower electrode 23-11 of the photodiode PD11 is set in the area surrounded by two gate lines GL and two signal lines SL. The photodiodes PD12, PD13, and PD14 are arranged at the outermost periphery of the detection area AA. The area of ​​the lower electrodes 23-12, 23-13, and 23-14 of the photodiodes PD12, PD13, and PD14 arranged at the outermost periphery is larger than the area of ​​the lower electrode 23-11 of the photodiode PD11 arranged on the inner side.

[0089] In more detail, the photodiode PD12 is adjacent to the photodiode PD11 in the second direction Dy and is arranged along the side of the detection area AA extending in the first direction Dx. The lower electrode 23-12 of the photodiode PD12 arranged at the outermost periphery in the second direction Dy extends to a region further outward than the side surface 30e4 of the organic semiconductor layer 30 in the second direction Dy when viewed from above. The width Wx12 of the lower electrode 23-12 of the photodiode PD12 in the first direction Dx is equal to the width Wx11 of the lower electrode 23-11 of the photodiode PD11 in the first direction Dx. The width Wy12 of the lower electrode 23-12 of the photodiode PD12 in the second direction Dy is greater than the width Wy11 of the lower electrode 23-11 of the photodiode PD11 in the second direction Dy.

[0090] The photodiode PD13 is adjacent to the photodiode PD11 in the first direction Dx and is arranged along the side of the detection area AA extending in the second direction Dy. The lower electrode 23-13 of the photodiode PD13 arranged at the outermost periphery in the first direction Dx extends to an area further outward than the side surface 30e2 of the organic semiconductor layer 30 in the first direction Dx when viewed from above. The width Wx13 of the lower electrode 23-13 of the photodiode PD13 in the first direction Dx is greater than the width Wx11 of the lower electrode 23-11 of the photodiode PD11 in the first direction Dx. The width Wy13 of the lower electrode 23-13 of the photodiode PD13 in the second direction Dy is equivalent to the width Wy11 of the lower electrode 23-11 of the photodiode PD11 in the second direction Dy.

[0091] The photodiode PD14 is adjacent to the photodiode PD11 in the oblique direction and is disposed at the corner of the detection area AA. The lower electrode 23-14 of the photodiode PD14 disposed at the corner at the outermost periphery of the detection area AA extends along the first direction Dx and the second direction Dy to an area further outward than the side surface 30e2 and the side surface 30e4 of the organic semiconductor layer 30 when viewed from above. The width Wx14 of the lower electrode 23-14 of the photodiode PD14 in the first direction Dx is greater than the width Wx11 of the lower electrode 23-11 of the photodiode PD11 in the first direction Dx. The width Wy14 of the lower electrode 23-14 of the photodiode PD14 in the second direction Dy is greater than the width Wy11 of the lower electrode 23-11 of the photodiode PD11 in the second direction Dy.

[0092] It should be noted that in Figure 8 In the example, four photodiodes PD11, PD12, PD13, PD14 are shown, but in Figure 8 The description in FIG. 1 can also be applied to other photodiodes PD arranged in the central portion of the detection area AA and other photodiodes PD arranged in the outermost periphery of the detection area AA.

[0093] Fig. 9 for Figure 8 IX-IX' section view. Fig. 9 As shown, the organic semiconductor layer 30 spans across a plurality of photodiodes PD ( Fig. 9 The lower electrode 23 - 12 of the photodiode PD12 and the lower electrode 23 - 14 of the photodiode PD14 are arranged to be separated by a space provided at a position overlapping with the signal line SL.

[0094] The lower electrode 23-14 of the photodiode PD14 extends from the region overlapping the organic semiconductor layer 30 to the region outside the side surface 30e2 of the organic semiconductor layer 30. The portion of the lower electrode 23-14 extending outside the side surface 30e2 overlaps the outermost signal line SL.

[0095] Fig.10 for Figure 6 X-X' section view. Fig.10 2 is a cross-sectional view showing the connection structure between the upper electrode 24, the terminal portion 25, and the power supply wiring CL2 of the detection device 1A. Fig.10As shown, the connection portion 24a of the upper electrode 24 and the connection portion 30a of the organic semiconductor layer 30 are provided at a position corresponding to the photodiode PD14 and extend along the second direction Dy from the side surface 30e4 of the organic semiconductor layer 30. The connection portion 30a of the organic semiconductor layer 30 is provided across the upper side of the signal line selection circuit 16 and extends to a position closer to the terminal portion 25 than the signal line selection circuit 16.

[0096] The conductive layer 26 is provided to cover the upper surface of the connection portion 24a of the upper electrode 24 and the side surfaces of the connection portion 24a of the upper electrode 24 and the side surfaces of the connection portion 30a of the organic semiconductor layer 30. The conductive layer 26 extends from the side surfaces of the connection portion 30a in the second direction Dy and is provided to overlap with the terminal portion 25. The terminal portion 25 is electrically connected to the power supply wiring CL2 through the contact hole CH11 provided in the insulating film 27.

[0097] With such a configuration, the upper electrodes 24 of the plurality of photodiodes PD are electrically connected to the power supply line CL2 via the conductive layer 26 and the terminal portion 25. The sensor power supply signal VDDSNS (see FIG. 1 ) is supplied to the upper electrodes 24, which are anodes of the plurality of photodiodes PD, via the power supply line CL2. Figure 7 ).

[0098] It should be noted that, even in the second embodiment, the cutout portion 23a (see Figure 4 ) may also be provided on the lower electrode 23 - 14 of the photodiode PD14 provided with the connection portion 30 a of the organic semiconductor layer 30 .

[0099] According to the above configuration, in the second embodiment, the organic semiconductor layer 30 of the photodiode PD disposed at the outermost periphery can reduce the area of ​​the portion that does not overlap with the lower electrode 23, compared to a configuration in which the organic semiconductor layer 30 covers the lower electrode 23 and is provided outside the outermost periphery of the lower electrode 23. As a result, the photocarriers generated in the outer edge of the organic semiconductor layer 30 quickly reach the lower electrode 23. Therefore, the detection device 1A can suppress the delay of the light response and improve the detection accuracy.

[0100] It should be noted that in the first embodiment and the second embodiment, the lower electrode 23 is the cathode electrode of the photodiode PD, and the upper electrode 24 is the anode electrode of the photodiode PD. However, this is not limited to this, and the lower electrode 23 may be the anode electrode of the photodiode PD, and the upper electrode 24 may be the cathode electrode of the photodiode PD. In this case, in the photodiode PD, the lower buffer layer 32 is configured to include a hole transport layer, and the upper buffer layer 33 is configured to include an electron transport layer.

[0101] In addition, in the first embodiment and the second embodiment described above, the outer shape of the lower electrode 23 is a quadrilateral, but the present invention is not limited thereto and the lower electrode 23 may be in other shapes such as a polygonal shape or a circular shape.

[0102] The preferred embodiments of the present invention are described above, but the present invention is not limited to such embodiments. The contents disclosed in the embodiments are only examples, and various changes can be made without departing from the gist of the present invention. Suitable changes made without departing from the gist of the present invention also belong to the technical scope of the present invention. Without departing from the gist of the above-mentioned embodiments and variations, at least one of the various omissions, substitutions and changes of the constituent elements can be made.

[0103] Description of Reference Numerals

[0104] 1, 1A: detection device, 15: gate line driving circuit, 16: signal line selection circuit, 21: substrate, 23, 23-11, 23-12, 23-13, 23-14: lower electrode, 23a: cutout portion, 24: upper electrode, 24a: connection portion, 27: insulating film, 28: sealing film, 30: organic semiconductor layer, 30a: connection portion, 30e1, 30e2, 30e3, 30e4: side, 31: active layer, 32: lower buffer layer, 33: upper buffer layer, 48: detection circuit, PD, PD11, PD12, PD13, PD14: photodiode, AA: detection area, CL1, CL2: power supply wiring, GA: peripheral area, GL: gate line, SL: signal line.

Claims

1. A detection device, comprising: substrate; and a photodiode, wherein the photodiode is stacked on the substrate in the order of a lower electrode, a lower buffer layer, an active layer, an upper buffer layer and an upper electrode, The lower electrode is extended from a region overlapping with the organic semiconductor layer including the lower buffer layer, the active layer, and the upper buffer layer to a region outside a side surface of the organic semiconductor layer in a plan view.

2. The detection device according to claim 1, wherein: The detection device has a plurality of photodiodes. The plurality of lower electrodes are arranged corresponding to the plurality of photodiodes, respectively, and are extended to a region outside the side surface of the organic semiconductor layer in at least the first direction. The plurality of photodiodes are arranged along a second direction intersecting the first direction, The upper electrode is extended in the second direction across the plurality of photodiodes.

3. The detection device according to claim 2, wherein: The plurality of lower electrodes are arranged along the second direction, The lower electrode disposed outermost in the second direction extends to a region outside the side surface of the organic semiconductor layer in the first direction and extends to a region outside the side surface in the second direction.

4. The detection device according to claim 1, wherein: The detection device comprises: a signal line electrically connected to the lower electrode of the photodiode; a detection circuit, electrically connected to the photodiode via the signal line; as well as A power supply wiring is electrically connected to the upper electrode via the conductive layer, A predetermined potential is supplied to the upper electrode via the conductive layer and the power supply wiring.

5. The detection device according to claim 1, wherein: The detection device comprises a plurality of the photodiodes arranged in a matrix along a first direction and a second direction intersecting the first direction. The plurality of lower electrodes are arranged corresponding to the plurality of photodiodes, respectively. The upper electrode is arranged across a plurality of the photodiodes, The lower electrode of the photodiode disposed at the outermost periphery is extended to a region outside the side surface of the organic semiconductor layer in a plan view.

6. The detection device according to claim 5, wherein: The area of ​​the lower electrode of the photodiode arranged at the outermost periphery is larger than the area of ​​the lower electrode of the photodiode arranged at the inner side.

7. The detection device according to claim 5 or 6, wherein: The detection device also has: A plurality of gate lines connected to a gate line driving circuit; a plurality of signal lines connected to the signal line selection circuit; and A transistor is provided on each of the photodiodes, The plurality of gate lines are respectively connected to the plurality of transistors arranged along the first direction, The plurality of signal lines are respectively connected to the plurality of transistors arranged along the second direction, The gate line driving circuit drives the plurality of gate lines row by row, The signal line selection circuit sequentially reads out the plurality of signal lines.

8. The detection device according to claim 2, wherein: The photodiodes corresponding to the locations electrically connected to the upper electrode and the power supply wiring among the plurality of photodiodes are dummy photodiodes.

9. The detection device according to claim 2, wherein: The lower electrodes of the photodiodes corresponding to the locations of the plurality of photodiodes electrically connected to the upper electrodes and the power supply wiring have cutout portions.

10. The detection device according to claim 1, wherein: The lower buffer layer includes any one of a hole transport layer and an electron transport layer, The upper buffer layer includes any other of the hole transport layer or the electron transport layer.

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