Detection device

Abstract

This detection device comprises a substrate and a photodiode disposed on the substrate in which a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode are stacked in this order. In a plan view, the lower electrode is provided extending from a region overlapping an 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. Further, a detection device comprises a plurality of the photodiodes, wherein a plurality of the lower electrodes are arrayed respectively corresponding to the plurality of photodiodes and extend to a region outside the side surface of the organic semiconductor layer in at least a first direction. A plurality of the photodiodes are arrayed in a second direction intersecting the first direction, and the upper electrode is provided extending across the plurality of photodiodes in the second direction.

Description

[Technical Field]

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

[0002] Optical sensors capable of detecting fingerprint patterns and vein patterns are known (see, for example, Patent Document 1). Such optical sensors have multiple photodiodes that use an organic semiconductor material as an active layer. As described in Patent Document 2, the photodiodes are disposed between a lower electrode and an upper electrode, and for example, the lower electrode, electron transport layer, active layer, hole transport layer, and upper electrode are stacked in this order. The electron transport layer or hole transport layer is also called a buffer layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-32005 [Patent Document 2] International Publication No. 2020 / 188959 Summary of the Invention [Problem to be solved by the invention]

[0004] In some cases, an organic semiconductor layer including an electron transport layer, an active layer, and a hole transport layer is provided with an area larger than that of the lower electrode. Photocarriers generated in the organic semiconductor layer in the portion not overlapping with the lower electrode reach the lower electrode later than photocarriers generated in the organic semiconductor layer in the portion overlapping with the lower electrode. As a result, the photocarriers generated in the organic semiconductor layer in the portion not overlapping with the lower electrode may not be read sufficiently, resulting in reduced detection accuracy. Alternatively, the readout period may be extended to read out photocarriers generated in the organic semiconductor layer in the portion not overlapping with the lower electrode, resulting in reduced detection speed.

[0005] An object of the present invention is to provide a detection device that can improve detection accuracy. [Means for solving the problem]

[0006] A detection device according to one embodiment of the present invention includes a substrate and a photodiode having a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode stacked in this order on the substrate, wherein the lower electrode extends from a region overlapping with an 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 planar view. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing a detection device according to a first embodiment. [Figure 2] FIG. 2 is a circuit diagram showing the detection device according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III' in FIG. [Figure 4] FIG. 4 is a plan view schematically showing the connection structure between the upper electrode and the terminal portion. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV' in FIG. [Figure 6] FIG. 6 is a plan view showing a detection device according to the second embodiment. [Figure 7] FIG. 7 is a circuit diagram showing a detection device according to the second embodiment. [Figure 8] FIG. 8 is an enlarged plan view showing four photodiodes arranged at the corners of the detection area. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX' of FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along the line XX' in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present disclosure is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the components described below can be combined as appropriate. Note that the disclosure is merely an example, and any appropriate modifications that a person skilled in the art can easily make while maintaining the gist of the present disclosure are naturally included within the scope of the present disclosure. Furthermore, for clarity of explanation, the drawings may schematically depict the width, thickness, shape, etc. of each part compared to the actual embodiment. However, these are merely examples and are not intended to limit the interpretation of the present disclosure. Furthermore, in this disclosure and each figure, elements similar to those previously described with reference to the preceding figures may be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0009] In this specification and claims, when expressing an aspect of placing another structure on top of a certain structure, the term "on top" is used, unless otherwise specified, to include both a case in which another structure is placed directly on top of a certain structure so as to be in contact with the certain structure, and a case in which another structure is placed above a certain structure via yet another structure.

[0010] (First embodiment) Fig. 1 is a plan view showing a detection device according to the first embodiment. Fig. 2 is a circuit diagram showing the detection device according to the first embodiment. As shown in Figs. 1 and 2, the detection device 1 has a substrate 21, a plurality of photodiodes PD, a plurality of signal lines SL, a power supply line CL1, and a control circuit 122.

[0011] The substrate 21 has a detection area AA and a peripheral area GA. The detection area AA is an area in which a plurality of photodiodes PD are provided. The peripheral area GA is an area between the periphery of the detection area AA and the edge of the substrate 21, and is an area in which the plurality of photodiodes PD are not provided. The plurality of signal lines SL and the control circuit 122 are provided in the peripheral area GA of the substrate 21.

[0012] 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 perpendicular to the first direction Dx. The second direction Dy may intersect the first direction Dx without being perpendicular thereto. The third direction Dz is a direction perpendicular to the first direction Dx and the second direction Dy. The third direction Dz is a normal direction to the substrate 21. Furthermore, "planar view" refers to the positional relationship when viewed from a direction perpendicular to the substrate 21.

[0013] The detection device 1 has a plurality of photodiodes PD as optical sensor elements. Each photodiode PD outputs an electrical signal corresponding to the light irradiated thereon. More specifically, the photodiodes PD are organic photodiodes (OPDs) that use organic semiconductors. The plurality of photodiodes PD are arranged side by side in the second direction Dy in the detection area AA.

[0014] 2, the cathodes (lower electrodes 23) of the multiple photodiodes PD are connected to a detection circuit 48 via signal lines SL, and the anodes (upper electrodes 24) of the multiple photodiodes PD are connected to a power supply circuit 123 via a common power supply wiring CL1.

[0015] More specifically, as shown in FIG. 1, the multiple photodiodes PD include an organic semiconductor layer 30 (a lower buffer layer 32, an active layer 31, and an upper buffer layer 33 (see FIG. 3)), a lower electrode 23 disposed below the organic semiconductor layer 30, and an upper electrode 24 disposed above the organic semiconductor layer 30. The multiple lower electrodes 23 are provided corresponding to the multiple photodiodes PD, respectively, and are arranged side by side in the second direction Dy in the detection area AA. The multiple lower electrodes 23 are also arranged spaced apart in the second direction Dy.

[0016] The organic semiconductor layer 30 and the upper electrode 24 are provided extending in the second direction Dy across the multiple photodiodes PD and are provided continuously in the detection area AA. The organic semiconductor layer 30 has four side surfaces 30e1, 30e2, 30e3, and 30e4 and is formed in a substantially rectangular shape in a plan view. The organic semiconductor layer 30 has one side surface 30e1 in the first direction Dx, the other side surface 30e2 in the first direction Dx, one side surface 30e3 in the second direction Dy, and the other side surface 30e4 in the second direction Dy. In the first direction Dx, the side surface 30e2 is located on the opposite side to the side surface 30e1. In addition, in the second direction Dy, the side surface 30e4 is located on the opposite side to the side surface 30e3. The stacked configuration of the organic semiconductor layer 30, the lower electrode 23, and the upper electrode 24 of the photodiode PD will be described later with reference to FIG. 3.

[0017] The signal lines SL are electrically connected to the lower electrodes 23 of the photodiodes PD, respectively. Specifically, in the example shown in Fig. 1, the signal lines SL are connected to the lower electrodes 23, respectively, via contact holes CH1 formed in the insulating film 27 (see Fig. 3).

[0018] Each of the multiple signal lines SL extends in a first direction Dx from a connection point (contact hole CH1) with the lower electrode 23, bends in a second direction Dy, and extends in the second direction Dy along the arrangement direction of the multiple photodiodes PD. The portions of the multiple signal lines SL extending in the second direction Dy are arranged in the first direction Dx. The multiple signal lines SL are connected to a 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 multiple photodiodes PD via the multiple signal lines SL.

[0019] The upper electrode 24 is provided extending in the second direction Dy across the detection region AA and the peripheral region GA. Connection portions 24a and 30a are provided at the outer edge portions of the upper electrode 24 and the organic semiconductor layer 30 on the other side in the second direction Dy (the lower side in FIG. 1), respectively. The connection portions 24a and 30a are provided extending from the detection region AA toward the peripheral region GA, and are electrically connected to the terminal portion 25 via the conductive layer 26. The terminal portion 25 is electrically connected to the power supply wiring CL1 via a contact hole CH2.

[0020] With this configuration, the upper electrodes 24 of the multiple photodiodes PD are connected to the power supply circuit 123 included in the control circuit 122 via the conductive layer 26, the terminal portion 25, and the power supply wiring CL1. The power supply circuit 123 supplies a sensor reference voltage COM to the upper electrodes 24 of the photodiodes PD.

[0021] The control circuit 122 (detection circuit 48 and power supply circuit 123) is disposed adjacent to the photodiodes 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 multiple photodiodes PD to control their detection operations. The multiple photodiodes PD output electrical signals corresponding to the light irradiated thereon as detection signals Vdet to the detection circuit 48. In this embodiment, the detection signals Vdet of the multiple photodiodes PD are output to the detection circuit 48 sequentially in a time-division manner. In other words, the multiple signal lines SL are electrically connected to the detection circuit 48 sequentially in a time-division manner. As a result, the detection device 1 detects information about the object to be detected based on the detection signals Vdet from the multiple photodiodes PD.

[0022] The control circuit 122 (detection circuit 48 and power supply circuit 123) is provided on the same substrate 21 as the multiple photodiodes PD, but is not limited to this. The control circuit 122 (detection circuit 48 and power supply circuit 123) may be provided on a separate control substrate connected to the substrate 21 via, for example, a flexible printed circuit board. The detection circuit 48 and the power supply circuit 123 may also be formed as separate circuits.

[0023] Although not shown in Fig. 1, the detection device 1 may have one or more light sources. The light source may be, for example, an inorganic light emitting diode (LED) or an organic light emitting diode (OLED).

[0024] Light emitted from the light source is reflected by the surface of the object to be detected, such as a finger, and enters multiple photodiodes PD. This allows the detection device 1 to detect a fingerprint by detecting the uneven shape of the surface of the finger or the like. Alternatively, the light emitted from the light source may be reflected inside the finger or the like or pass through the finger or the like and enter multiple photodiodes PD. This allows the detection device 1 to detect information about a living body inside the finger or the like. The information about a living body includes, for example, the pulse wave, pulse rate, and blood vessel image of the finger or palm. In other words, the detection device 1 may be configured as a fingerprint detection device that detects fingerprints, or a vein detection device that detects blood vessel patterns such as veins.

[0025] Next, a description will be given of the laminated structure of the organic semiconductor layer 30, the lower electrode 23, and the upper electrode 24 of the photodiode PD. Fig. 3 is a cross-sectional view taken along line III-III' in Fig. 1.

[0026] 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 will be referred to as the "upper side" or simply "upper." The direction from the sealing film 28 toward the substrate 21 will be referred to as the "lower side" or simply "lower."

[0027] 3, the substrate 21 is an insulating substrate, and is made of, for example, glass or a resin material. The substrate 21 is not limited to a flat plate shape, and may have a curved surface. In this case, the substrate 21 may be a film-like resin.

[0028] The signal line SL is provided on the substrate 21. The signal line SL is formed, for example, of a metal wiring, and is formed of a material having better conductivity than the lower electrode 23 of the photodiode PD. A portion of the signal line SL (the right end side of the signal line SL in FIG. 3) is provided in a layer between the substrate 21 and the lower electrode 23 of the photodiode PD in the third direction Dz. The insulating film 27 is provided on the substrate 21 to cover the signal line SL. The insulating film 27 may be an inorganic insulating film or an organic insulating film. The insulating film 27 may be a single layer or a laminated film.

[0029] The photodiode PD is provided on the insulating film 27. More specifically, 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. In the photodiode PD, 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 are stacked in this order in a direction perpendicular to the substrate 21.

[0030] The lower electrode 23 is provided on the insulating film 27 and is electrically connected to the signal line SL via a contact hole CH1 provided in the insulating film 27. The lower electrode 23 is the cathode electrode of the photodiode PD and is made 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 optical sensor in which light from the object to be detected passes through the substrate 21 and enters the photodiode PD.

[0031] The characteristics (for example, voltage-current characteristics and resistance value) of the active layer 31 change depending on the light irradiated thereon. An organic material is used as the material of the active layer 31. Specifically, the active layer 31 has a bulk heterostructure in which a p-type organic semiconductor and an n-type organic semiconductor, an n-type fullerene derivative (PCBM), are mixed. For example, low-molecular-weight organic materials such as C60 (fullerene), PCBM (phenyl C61-butyric acid methyl ester), CuPc (copper phthalocyanine), F16CuPc (fluorinated copper phthalocyanine), rubrene (5,6,11,12-tetraphenyltetracene), and PDI (perylene derivative) can be used as the active layer 31.

[0032] The active layer 31 can be formed by a vapor deposition method (dry process) using these low-molecular-weight organic materials. In this case, the active layer 31 may be, for example, a laminated film of CuPc and F16CuPc, or a laminated film of rubrene and C60. The active layer 31 can also be formed by a coating method (wet process). In this case, the active layer 31 is made of a material that combines the above-mentioned low-molecular-weight organic material with a high-molecular-weight organic material. Examples of high-molecular-weight organic materials that can be used include P3HT (poly(3-hexylthiophene)) and F8BT (F8-alt-benzothiadiazole). The active layer 31 can be a film in which P3HT and PCBM are mixed, or a film in which F8BT and PDI are mixed.

[0033] 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 make it easier for 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 in direct contact with the upper surface of the lower electrode 23. The active layer 31 is in direct contact with the upper surface of the lower buffer layer 32. Ethoxylated polyethyleneimine (PEIE) is used as the material for the electron transport layer.

[0034] The upper buffer layer 33 (hole transport layer) is in direct contact with the active layer 31, and the upper electrode 24 is in direct contact with the upper buffer layer 33. The material of the hole transport layer is a metal oxide layer. Examples of the metal oxide layer include tungsten oxide (WO3) and molybdenum oxide.

[0035] The materials and manufacturing methods of the lower buffer layer 32, the active layer 31, and the upper buffer layer 33 are merely examples, and other materials and manufacturing methods may be used. For example, the lower buffer layer 32 and the upper buffer layer 33 are not limited to single-layer films, and may be formed as multilayer films including an electron blocking layer and a hole blocking layer.

[0036] The upper electrode 24 is provided on the upper buffer layer 33. The upper electrode 24 is an anode electrode of the photodiode PD, and is formed continuously over the entire detection area AA. In other words, the upper electrode 24 is provided continuously over the multiple photodiodes PD. The upper electrode 24 faces the multiple lower electrodes 23, with the lower buffer layer 32, active layer 31, and upper buffer layer 33 interposed therebetween. The upper electrode 24 is formed of a light-transmitting conductive material such as ITO or IZO.

[0037] The sealing film 28 is provided on the upper electrode 24. The sealing film 28 is made of an inorganic film such as a silicon nitride film or an aluminum oxide film, or a resin film such as acrylic. The sealing film 28 is not limited to a single layer, but may be a laminated film of two or more layers combining the inorganic film and the resin film. The sealing film 28 effectively seals the photodiode PD and can prevent moisture from entering from the upper surface side.

[0038] In this embodiment, the lower electrode 23 extends from a 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 a region outside the side surfaces 30e1 and 30e2 of the organic semiconductor layer 30. More specifically, the lower electrode 23 extends to a region outside one side surface 30e1 of the organic semiconductor layer 30 in the first direction Dx, and also extends to a 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 larger 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. The organic semiconductor layer 30 is disposed so as to overlap the lower electrode 23 from one side surface 30e1 in the first direction Dx to the other side surface 30e2 in the first direction Dx.

[0039] With this configuration, the organic semiconductor layer 30 does not have any portion that does not overlap with the lower electrode 23 at least in the first direction Dx. Therefore, compared to a configuration in which the organic semiconductor layer 30 covers the lower electrode 23 and is provided beyond the outer edge of the lower electrode 23, photocarriers generated in the organic semiconductor layer 30 reach the lower electrode 23 more quickly. Therefore, the detection device 1 can suppress delays in photoresponse and improve detection accuracy.

[0040] Furthermore, 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 of the lower electrode 23 extending outward from the side surface 30e2 of the organic semiconductor layer 30 on the opposite side of the first direction Dx. However, without being limited thereto, 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, to be larger than the amount of misalignment that occurs during the coating and patterning steps when forming the organic semiconductor layer 30.

[0041] 3 shows a configuration in which the lower electrode 23 extends to a region outside the side surfaces 30e1 and 30e2 of the organic semiconductor layer 30 in the first direction Dx, but is not limited thereto. As shown in Fig. 1, the outermost lower electrode 23 (the lower electrode 23 farthest from the terminal portion 25) on one side in the second direction Dy (the upper side in Fig. 1) is provided to extend to a region outside the side surfaces 30e1 and 30e2 of the organic semiconductor layer 30 in the first direction Dx, and also to a region outside one side surface 30e3 in the second direction Dy.

[0042] Furthermore, on the other side of the second direction Dy (the lower side in Figure 1), the outermost arranged lower electrode 23 (the lower electrode 23 closest to the terminal portion 25) is provided so as to extend to an area outside the side surfaces 30e1 and 30e2 of the organic semiconductor layer 30 in the first direction Dx, and is also provided so as to extend to an area outside the other side surface 30e4 in the second direction Dy.

[0043] With this configuration, one side surface 30e3 of the organic semiconductor layer 30 in the second direction Dy and the other side surface 30e4 in the second direction Dy are each positioned inside the outermost periphery of the plurality of lower electrodes 23. As a result, in the photodiodes PD respectively positioned outermost on one side and the other side in the second direction Dy, photocarriers generated in the organic semiconductor layer 30 can quickly reach the lower electrodes 23, thereby suppressing photoresponse delay.

[0044] Next, the connection configuration between the upper electrodes 24 of the multiple photodiodes PD, the terminal portions 25, and the power supply wiring CL1 will be described in detail. Fig. 4 is a plan view schematically showing the connection configuration between the upper electrodes and the terminal portions. Fig. 5 is a cross-sectional view taken along the line VV' in Fig. 4.

[0045] 4 and 5, the lower electrode 23 of the photodiode PD corresponding to the location where the upper electrode 24 and the power supply wiring CL1 are electrically connected has a notch 23a. Here, the photodiode PD corresponding to the location where the upper electrode 24 and the power supply wiring CL1 are electrically connected is the photodiode PD arranged outermost on the other side of the second direction Dy (the photodiode PD closest to the terminal portion 25) among the multiple photodiodes PD.

[0046] The cutout portion 23a of the lower electrode 23 is formed as a trapezoidal recess extending 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 disposed so as to overlap the cutout portion 23a of the lower electrode 23 and protrudes in the second direction Dy from the side surface 30e4 of the organic semiconductor layer 30. A widening portion is provided at the connection point between the side surface 30e4 of the organic semiconductor layer 30 and the connection portion 30a, where the width of the connection portion 30a in the first direction Dx gradually increases. Furthermore, the connection portion 24a connected to the upper electrode 24 is provided so as to overlap the connection portion 30a of the organic semiconductor layer 30.

[0047] 5, the conductive layer 26 is provided to cover the upper surface of the connection portion 24a of the upper electrode 24, as well as 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 in the second direction Dy and is provided to overlap with the terminal portion 25. The connection portion 30a of the organic semiconductor layer 30 and the connection portion 24a of the upper electrode 24 are formed integrally and continuously with the organic semiconductor layer 30 and the upper electrode 24, and have the same layered structure as the organic semiconductor layer 30 and the upper electrode 24.

[0048] 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 this configuration, the upper electrode 24 of the photodiode PD is electrically connected to the power supply line CL1 through the conductive layer 26 and the terminal portion 25.

[0049] In this embodiment, the cutout portion 23a is provided in the lower electrode 23, and therefore, even when the conductive layer 26 is disposed close to the outer edge portion 23e of the lower electrode 23, it is possible to ensure the distance M1 between the cutout portion 23a of the lower electrode 23 and the conductive layer 26 in the second direction Dy. This allows the detection device 1 to ensure insulation between the lower electrode 23 and the conductive layer 26 and to achieve a narrow frame.

[0050] 4 and 5 are merely examples of the connection configuration between the upper electrode 24, the terminal portion 25, and the power supply wiring CL1, and can be modified as appropriate. For example, the notch 23a of the lower electrode 23 can be omitted depending on the characteristics.

[0051] Alternatively, among the multiple photodiodes PD, the photodiode PD corresponding to the location where the upper electrode 24 and the power supply wiring CL1 are electrically connected (the photodiode PD arranged outermost on the other side in the second direction Dy in FIG. 1) may be a dummy photodiode. Here, the dummy photodiode has the same layered structure as the photodiode PD, but is configured so as not to substantially function as a photodiode. For example, the signal line SL may not be connected to the lower electrode 23 of the dummy photodiode, and the detection signal from the dummy photodiode may not be output to the detection circuit 48. Alternatively, the detection circuit 48 may be configured not to use the detection signal received from the dummy photodiode for detecting information related to a living organism.

[0052] In the first embodiment described above, the detection device 1 has been described as having four photodiodes PD. However, the detection device 1 is not limited to this, and may have five or more photodiodes PD. Alternatively, the detection device 1 is not limited to a configuration having a plurality of photodiodes PD, and may have at least one photodiode PD.

[0053] In the first embodiment described above, the photodiodes PD are arranged in the second direction Dy in the detection area AA. However, the present invention is not limited to this, and the photodiodes PD may be arranged in the first direction Dx in the detection area AA, or may be arranged in a matrix in the first direction Dx and the second direction Dy in the detection area AA.

[0054] (Second embodiment) 6 is a plan view showing a detection device according to the second embodiment. In the following description, the same components as those described in the above embodiments are denoted by the same reference numerals, and redundant description will be omitted.

[0055] 6, 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 drive 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. The first light source substrate 51 is provided with a plurality of light sources 53. The second light source substrate 52 is provided with a plurality of light sources 54.

[0056] A control board 121 is electrically connected to the substrate 21 via a wiring board 71. The wiring board 71 is, for example, a flexible printed circuit board or a rigid board. The detection circuit 48 is provided on the wiring board 71. The control board 121 is provided with a control circuit 122 and a power supply circuit 123. The control circuit 122 supplies control signals to the gate line driving circuit 15 and the signal line selection circuit 16 to control the detection operation of the sensor unit 10. The control circuit 122 also supplies control signals to the light sources 53 and 54 to control the lighting or non-lighting of the light sources 53 and 54. The power supply circuit 123 supplies voltage signals such as a sensor power supply signal VDDSNS (see FIG. 7) to the sensor unit 10, the gate line driving circuit 15, and the signal line selection circuit 16. The power supply circuit 123 also supplies a power supply voltage to the light sources 53 and 54.

[0057] The plurality of light sources 53 are provided on the first light source substrate 51 and arranged along the second direction Dy. The plurality of light sources 54 are provided 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 via terminal portions 124 and 125 provided on the control board 121, respectively.

[0058] The plurality of light sources 53 and the plurality of light sources 54 may be, for example, inorganic light emitting diodes (LEDs) or organic light emitting diodes (OLEDs). The plurality of light sources 53 and the plurality of light sources 54 each emit light of a different wavelength. The detection device 1 is provided with a plurality of types of light sources 53 and 54 as light sources. However, this is not limited thereto, and the light source may be of one type. For example, the first light source substrate 51 and the second light source substrate 52 may each be provided with a plurality of light sources 53 and a plurality of light sources 54. Furthermore, the number of light source substrates on which the light sources 53 and the light sources 54 are provided may be one or three or more. Alternatively, it is sufficient that at least one or more light sources are provided.

[0059] 6, in the detection device 1A according to the second embodiment, a plurality of photodiodes PD are arranged in a matrix in a detection area AA of a substrate 21. A plurality of lower electrodes 23 are provided corresponding to the plurality of photodiodes PD, respectively, and are arranged in a matrix in the detection area AA. In other words, the plurality of photodiodes PD (the plurality of lower electrodes 23) are arranged side by side in the first direction Dx and the second direction Dy.

[0060] The organic semiconductor layer 30 and the upper electrode 24 are provided across the multiple photodiodes PD and are provided continuously in the detection area AA. Although the upper electrode 24 is not shown in FIG. 6, the upper electrode 24 is formed in substantially the same shape as the organic semiconductor layer 30. In the detection device 1A of this embodiment, the lower electrodes 23 of the photodiodes PD arranged on the outermost periphery are provided to extend to areas outside the side surfaces 30e1, 30e2, 30e3, and 30e4 of the organic semiconductor layer 30 in a plan view. The configuration of the outermost lower electrodes 23 will be described in detail with reference to FIG. 8.

[0061] The gate line driving circuit 15 and the signal line selection circuit 16 are provided in the peripheral area GA. A plurality of gate lines GL extend in a first direction Dx and are connected to the gate line driving circuit 15. A plurality of signal lines SL extend in a second direction Dy and are connected to the signal line selection circuit 16. The plurality of photodiodes PD perform detection in accordance with gate driving signals supplied from the gate line driving circuit 15. Furthermore, the plurality of photodiodes PD output electrical signals corresponding to the light irradiated thereon as detection signals Vdet to the signal line selection circuit 16. As a result, the detection device 1A detects information about the object to be detected based on the detection signals Vdet from the plurality of photodiodes PD.

[0062] More specifically, the gate line drive circuit 15 drives a plurality of gate lines GL for each row. That is, the gate line drive circuit 15 sequentially or simultaneously selects the plurality of gate lines GL and supplies a gate drive signal to the selected gate lines GL. As a result, the drive transistors Tr (see FIG. 14) connected to the gate lines GL are turned on (conductive), and the lower electrodes 23 of the plurality of photodiodes PD connected to the gate lines GL are electrically connected to the signal lines SL via the drive transistors Tr.

[0063] The signal line selection circuit 16 is a switch circuit that sequentially or simultaneously selects multiple signal lines SL. The signal line selection circuit 16 is, for example, a multiplexer. The signal line selection circuit 16 sequentially reads out the multiple signal lines SL. That is, the signal line selection circuit 16 connects the selected signal line SL to the detection circuit 48 based on a selection signal supplied from the control circuit 122 (see FIG. 1).

[0064] Fig. 7 is a circuit diagram showing a detection device according to the second embodiment. Fig. 7 also shows the circuit configuration of a detection circuit 48. As shown in Fig. 7, the partial detection area PAA includes a photodiode PD, a capacitive element Ca, and a drive transistor Tr. The capacitive element Ca is a capacitance (sensor capacitance) formed in the photodiode PD, and is equivalently connected in parallel with the photodiode PD.

[0065] 7 shows two gate lines GL(m) and GL(m+1) aligned in the second direction Dy among the multiple gate lines GL. Also shown are two signal lines SL(n) and SL(n+1) aligned in the first direction Dx among the multiple signal lines SL. The partial detection area PAA is an area surrounded by the gate lines GL and the signal lines SL.

[0066] The drive transistors Tr are provided corresponding to the respective photodiodes PD. The drive transistors Tr are configured by thin film transistors, and in this example, are configured by n-channel MOS (Metal Oxide Semiconductor) TFTs (Thin Film Transistors).

[0067] Each of the gate lines GL is connected to the gates of a plurality of drive transistors Tr arranged in a first direction Dx. Each of the signal lines SL is connected to one of the source and drain of a plurality of drive transistors Tr arranged in a second direction Dy. The other of the source and drain of each of the drive transistors Tr is connected to the cathode of the photodiode PD and the capacitance element Ca.

[0068] A sensor power supply signal VDDSNS is supplied to the anode of the photodiode PD from the power supply circuit 123 (see FIG. 1). In addition, a sensor reference voltage COM, which serves as the initial potential of the signal line SL and the capacitance element Ca, is supplied to the signal line SL and the capacitance element Ca from the power supply circuit 123 via the reset transistor TrR.

[0069] When light is irradiated onto the partial detection area PAA during the exposure period, a current corresponding to the amount of light flows through the photodiode PD, causing charge to accumulate in the capacitance element Ca. When the drive transistor Tr is turned on during the readout period, a current corresponding to the charge accumulated in the capacitance element Ca flows through the signal line SL. The signal line SL is connected to the detection circuit 48 via the output transistor TrS of the signal line selection circuit 16. This allows the detection device 1A to detect a signal corresponding to the amount of light irradiated onto the photodiode PD for each partial detection area PAA.

[0070] During the readout period, the switch SSW of the detection circuit 48 is turned on, and the detection circuit 48 is connected to the signal line SL. The detection signal amplifier circuit 42 of the detection circuit 48 converts fluctuations in current supplied from the signal line SL into fluctuations in voltage and amplifies the voltage. A reference potential (Vref) having a fixed potential is input to the non-inverting input terminal (+) of the detection signal amplifier circuit 42, and the signal line SL is connected to the inverting input terminal (-). In this embodiment, a signal equal to the sensor reference voltage COM is input as the reference potential (Vref) voltage. The control circuit 122 (see FIG. 1) calculates the difference between the detection signal Vdet when light is irradiated and the detection signal Vdet when light is not irradiated as the sensor output voltage Vo. The detection signal amplifier circuit 42 also has a capacitance element Cb and a reset switch RSW. During the reset period, the reset switch RSW is turned on, and the charge of the capacitance element Cb is reset.

[0071] Fig. 8 is an enlarged plan view showing four photodiodes arranged at the corners of the detection area AA. Fig. 8 shows an enlarged view of four photodiodes PD11, PD12, PD13, and PD14 arranged at the corners of the detection area AA among the multiple photodiodes PD.

[0072] The photodiode PD11 is disposed toward the center of the detection area AA, i.e., farther from the sides of the detection area AA than the photodiodes PD12, PD13, and PD14. The lower electrode 23-11 of the photodiode PD11 is provided in an area surrounded by two gate lines GL and two signal lines SL. The photodiodes PD12, PD13, and PD14 are disposed on the outermost periphery of the detection area AA. The areas of the lower electrodes 23-12, 23-13, and 23-14 of the outermost photodiodes PD12, PD13, and PD14 are larger than the area of ​​the lower electrode 23-11 of the photodiode PD11 disposed on the inner side.

[0073] More specifically, the photodiode PD12 is adjacent to the photodiode PD11 in the second direction Dy and is provided along a 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 in the second direction Dy to an area outside the side surface 30e4 of the organic semiconductor layer 30 in a planar view. The width Wx12 in the first direction Dx of the lower electrode 23-12 of the photodiode PD12 is equal to the width Wx11 in the first direction Dx of the lower electrode 23-11 of the photodiode PD11. The width Wy12 in the second direction Dy of the lower electrode 23-12 of the photodiode PD12 is larger than the width Wy11 in the second direction Dy of the lower electrode 23-11 of the photodiode PD11.

[0074] The photodiode PD13 is adjacent to the photodiode PD11 in the first direction Dx and is provided along a 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 in the first direction Dx to an area outside the side surface 30e2 of the organic semiconductor layer 30 in a planar view. The width Wx13 in the first direction Dx of the lower electrode 23-13 of the photodiode PD13 is larger than the width Wx11 in the first direction Dx of the lower electrode 23-11 of the photodiode PD11. The width Wy13 in the second direction Dy of the lower electrode 23-13 of the photodiode PD13 is equal to the width Wy11 in the second direction Dy of the lower electrode 23-11 of the photodiode PD11.

[0075] The photodiode PD14 is diagonally adjacent to the photodiode PD11 and is provided at a corner of the detection area AA. The lower electrode 23-14 of the photodiode PD14, which is arranged at the corner on the outermost periphery of the detection area AA, extends in the first direction Dx and the second direction Dy to an area outside the side surfaces 30e2 and 30e4 of the organic semiconductor layer 30 in a planar view. The width Wx14 of the lower electrode 23-14 of the photodiode PD14 in the first direction Dx is larger 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 larger than the width Wy11 of the lower electrode 23-11 of the photodiode PD11 in the second direction Dy.

[0076] Although Figure 8 illustrates four photodiodes PD11, PD12, PD13, and PD14, the explanation in Figure 8 can also be applied to other photodiodes PD arranged in the center of the detection area AA and other photodiodes PD arranged on the outermost periphery of the detection area AA.

[0077] Fig. 9 is a cross-sectional view taken along line IX-IX' in Fig. 8. As shown in Fig. 9, the organic semiconductor layer 30 is provided across a plurality of photodiodes PD (photodiodes PD12 and PD14 are shown in 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 from each other via a space provided at a position overlapping the signal line SL.

[0078] The lower electrode 23-14 of the photodiode PD14 is provided to extend from a region overlapping with the organic semiconductor layer 30 to a 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 is provided to overlap with the outermost signal line SL.

[0079] 10 is a cross-sectional view taken along the line X-X' in FIG. 6. FIG. 10 is a cross-sectional view showing the connection configuration between the upper electrode 24 of the detection device 1A, the terminal portion 25, and the power supply wiring CL2. As shown in FIG. 10, 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 from the side surface 30e4 of the organic semiconductor layer 30 in the second direction Dy. 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.

[0080] The conductive layer 26 is provided to cover the upper surface of the connection portion 24a of the upper electrode 24, as well as 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 in the second direction Dy and is provided to overlap the terminal portion 25. The terminal portion 25 is electrically connected to the power supply line CL2 via a contact hole CH11 provided in the insulating film 27.

[0081] With this configuration, the upper electrodes 24 of the multiple photodiodes PD are electrically connected to the power supply wiring CL2 via the conductive layer 26 and the terminal portion 25. A sensor power supply signal VDDSNS (see FIG. 7) is supplied to the upper electrodes 24, which are the anodes of the multiple photodiodes PD, via the power supply wiring CL2.

[0082] Also in the second embodiment, the lower electrode 23-14 of the photodiode PD14 on which the connection portion 30a of the organic semiconductor layer 30 is provided may be provided with a notch portion 23a (see FIG. 4).

[0083] With the above-described configuration, in the second embodiment, the organic semiconductor layer 30 of the photodiode PD arranged on 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 beyond the outermost periphery of the lower electrode 23. This allows photocarriers generated at the outer edge of the organic semiconductor layer 30 to quickly reach the lower electrode 23. Therefore, the detection device 1A can suppress delays in photoresponse and improve detection accuracy.

[0084] In the first and second embodiments described above, 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, without being limited to this, 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, the photodiode PD is configured such that the lower buffer layer 32 includes a hole transport layer, and the upper buffer layer 33 includes an electron transport layer.

[0085] In the first and second embodiments described above, the outer shape of the lower electrode 23 is rectangular, but this is not limiting. The lower electrode 23 may have other shapes, such as a polygonal shape or a circular shape.

[0086] Although preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments. The contents disclosed in the embodiments are merely examples, and various modifications are possible without departing from the spirit of the present invention. Appropriate modifications made without departing from the spirit of the present invention naturally fall within the technical scope of the present invention. At least one of various omissions, substitutions, and modifications of components can be made without departing from the spirit of each of the above-described embodiments and modifications. [Explanation of symbols]

[0087] 1. 1A detection device 15 Gate line driving circuit 16 Signal line selection circuit 21 PCB 23, 23-11, 23-12, 23-13, 23-14 Lower electrode 23a Notch 24 Upper electrode 24a Connection 27 Insulating film 28 Sealing film 30 Organic semiconductor layer 30a connection 30e1, 30e2, 30e3, 30e4 side 31 Active layer 32 Lower buffer layer 33 Upper buffer layer 48 Detection circuit PD, PD11, PD12, PD13, PD14 photodiodes AA detection area CL1, CL2 power supply wiring GA peripheral area GL gate line SL signal line

Claims

1. A substrate; a photodiode having a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode stacked in this order on the substrate; the lower electrode is provided so as to extend from a region overlapping with an 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 first direction, in a plan view; The organic semiconductor layer is provided so as to extend to an area outside a side surface of the lower electrode in a second direction intersecting with the first direction. Detection device.

2. a plurality of the photodiodes; the plurality of lower electrodes are arranged corresponding to the plurality of photodiodes, respectively, and are provided so as to extend to an area outside at least a side surface of the organic semiconductor layer in the first direction; The plurality of photodiodes are arranged in the second direction, The upper electrode is provided to extend in the second direction across the plurality of photodiodes. The detection device according to claim 1 .

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

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

5. A photodiode array having a plurality of photodiodes arranged in a matrix in the first direction and the second direction, the plurality of lower electrodes are arranged corresponding to the plurality of photodiodes, respectively; the upper electrode is provided across the plurality of photodiodes, The lower electrodes of the photodiodes arranged on the outermost periphery are provided so as to extend to regions outside the side surfaces of the organic semiconductor layer in a plan view. The detection device according to claim 1 .

6. A substrate, a photodiode having a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode stacked in this order on the substrate; the lower electrode is provided so as to extend from a region overlapping with an 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; a plurality of the photodiodes arranged in a matrix in 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 provided across the plurality of photodiodes, the lower electrodes of the photodiodes arranged at the outermost periphery are provided so as to extend to regions outside the side surfaces of the organic semiconductor layer in a plan view, The area of ​​the bottom electrode of the photodiode arranged at the outermost periphery is larger than the area of ​​the bottom electrode of the photodiode arranged inside. Detection device.

7. a plurality of gate lines connected to a gate line driving circuit; a plurality of signal lines connected to a signal line selection circuit; a transistor provided for each of the photodiodes, Each of the plurality of gate lines is connected to a plurality of the transistors arranged in the first direction, each of the plurality of signal lines is connected to a plurality of the transistors arranged in the second direction; the gate line driving circuit drives a plurality of the gate lines for each row; The signal line selection circuit sequentially reads out the plurality of signal lines. The detection device according to claim 5 or 6.

8. A substrate; a photodiode having a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode stacked in this order on the substrate; the lower electrode is provided so as to extend from a region overlapping with an 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; a plurality of the photodiodes; the plurality of lower electrodes are arranged corresponding to the plurality of photodiodes, respectively, and are provided so as to extend to an area outside at least a side surface of the organic semiconductor layer in a first direction; the plurality of photodiodes are arranged in a second direction intersecting the first direction, the upper electrode is provided extending in the second direction across the plurality of photodiodes, Among the plurality of photodiodes, the photodiode corresponding to the location where the upper electrode and the power supply wiring are electrically connected is a dummy photodiode. Detection device.

9. A substrate; a photodiode having a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode stacked in this order on the substrate; the lower electrode is provided so as to extend from a region overlapping with an 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; a plurality of the photodiodes; the plurality of lower electrodes are arranged corresponding to the plurality of photodiodes, respectively, and are provided so as to extend to an area outside at least a side surface of the organic semiconductor layer in a first direction; the plurality of photodiodes are arranged in a second direction intersecting the first direction, the upper electrode is provided extending in the second direction across the plurality of photodiodes, Among the plurality of photodiodes, the lower electrode of the photodiode corresponding to the location where the upper electrode and the power supply wiring are electrically connected has a notch. Detection device.

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

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