Ray detector

Abstract

The invention discloses a ray detector which comprises a photosensitive structure, and the photosensitive structure comprises a first electrode, a first carrier layer, a photosensitive layer, a second carrier layer and a second electrode which are sequentially stacked. The buffer layer is arranged on at least one side of the first carrier layer and / or the second carrier layer and is used for improving the migration speed of carriers; wherein the energy level of each film layer in the photosensitive structure is gradually increased along the direction far away from the photosensitive layer.

Description

Technical Field

[0001] The present application belongs to the field of detection technology, and in particular, relates to a ray detector. Background Art

[0002] A radiation detector is a device that converts radiation energy into electrical signals that can be recorded. It is widely used in medical imaging, aviation and other fields. When radiation passes through objects of different densities or thicknesses and irradiates the radiation detector, the photosensitive layer in the radiation detector generates corresponding electron-hole pairs based on light of different intensities. These electrons and holes form current under the action of an external bias electric field, and then the current forms stored charges on the TFT (Thin Film Transistor) plate. By reading out the charges stored on the TFT plate, the electrical signal is digitized to form an image.

[0003] However, the carrier recombination rate in current X-ray detectors is relatively high, which affects the performance of X-ray detectors. Summary of the invention

[0004] The purpose of the present application is to provide a radiation detector that can reduce the carrier recombination rate and improve the performance of the detector.

[0005] In a first aspect, the present application provides a radiation detector, comprising a photosensitive structure, the photosensitive structure comprising a first electrode, a first carrier layer, a photosensitive layer, a second carrier layer and a second electrode stacked in sequence; and a buffer layer, the buffer layer being arranged on at least one side of the first carrier layer and / or the second carrier layer, for increasing the migration speed of the carriers; wherein the energy level of each film layer in the photosensitive structure gradually increases in a direction away from the photosensitive layer.

[0006] In some embodiments, the radiation detector further includes an array substrate, the array substrate includes a substrate and a driving circuit disposed on one side of the substrate, the photosensitive structure is disposed on one side of the substrate, and the driving circuit is electrically connected to the first electrode and the second electrode of the photosensitive structure respectively;

[0007] Preferably, the photosensitive structure is located on a side of the driving circuit facing away from the substrate.

[0008] In some embodiments, the driving circuit includes a transistor, and the array substrate also includes an insulating layer located on the side of the transistor away from the substrate, the insulating layer has a via, and the first electrode is located on the side of the insulating layer away from the substrate and connected to the transistor through the via.

[0009] In some embodiments, there are multiple photosensitive structures distributed in a direction parallel to the substrate, and there are multiple driving circuits of the array substrate, which are connected one-to-one to the first electrodes and the second electrodes of the multiple photosensitive structures.

[0010] In some embodiments, the material of the photosensitive layer includes a perovskite material;

[0011] Preferably, the material of the photosensitive layer includes a non-lead-based perovskite material.

[0012] In some embodiments, the material of the photosensitive layer includes a double-layer perovskite material and / or a triple-layer perovskite material;

[0013] Preferably, the material of the photosensitive layer includes A2B1B2X6, A3B2 III X9 and A2B IV At least one of X6.

[0014] In some embodiments, the material of the second carrier layer includes a P-type material, and the material of the first carrier layer includes an N-type material;

[0015] Preferably, the P-type material and / or the N-type material comprises one of an inorganic oxide and a perovskite material;

[0016] Preferably, the perovskite material comprises an inorganic perovskite material and / or an organic-inorganic perovskite material.

[0017] In some embodiments, the buffer layer includes a first sub-buffer layer, the first sub-buffer layer is disposed between the second electrode and the second carrier layer, and the energy level of the first sub-buffer layer is greater than the energy level of the second carrier layer and less than the energy level of the second electrode;

[0018] Preferably, the material of the first sub-buffer layer includes ytterbium and / or aluminum.

[0019] In some embodiments, the radiation detector further includes a packaging structure, the packaging structure includes a first packaging layer, and the first packaging layer covers the photosensitive structure;

[0020] Preferably, the material of the first encapsulation layer includes an inorganic material.

[0021] In some embodiments, the encapsulation structure further includes a second encapsulation layer, and the second encapsulation layer is disposed on a side of the first encapsulation layer away from the photosensitive structure;

[0022] Preferably, the material of the second encapsulation layer comprises an organic material;

[0023] Preferably, the encapsulation structure further comprises a third encapsulation layer, and the third encapsulation layer is arranged on a side of the second encapsulation layer away from the photosensitive structure;

[0024] Preferably, the material of the third encapsulation layer includes an inorganic material.

[0025] An embodiment of the present application provides a radiation detector, including a photosensitive structure, wherein the photosensitive structure includes a first electrode, a first carrier layer, a photosensitive layer, a second carrier layer, and a second electrode, which are stacked together, so that a light signal can be converted into an electrical signal through the cooperation of the above-mentioned film layers. In addition, the photosensitive structure also includes a buffer layer, which is arranged on at least one side of the first carrier layer and / or the second carrier layer. In the direction away from the photosensitive layer, the energy level of each film layer in the photosensitive structure gradually increases, so that the energy level of the buffer layer is between the energy levels of its two adjacent film layers, so that the buffer layer can accelerate the carrier migration speed between its two adjacent film layers, reduce the carrier recombination rate, and improve the performance of the radiation detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A cross-sectional schematic diagram of a radiation detector provided in some embodiments of the present application;

[0028] Figure 2 Another cross-sectional schematic diagram of a radiation detector provided in some embodiments of the present application;

[0029] Figure 3 A cross-sectional schematic diagram of a radiation detector provided in some embodiments of the present application;

[0030] Figure 4 A top view of a radiation detector provided in some embodiments of the present application;

[0031] Figure 5 A structural diagram of a single-layer perovskite material provided for some embodiments of the present application;

[0032] Figure 6 A cross-sectional schematic diagram of a ray detector provided for related technology;

[0033] Figure 7 A structural diagram of a double-layer perovskite provided for some embodiments of the present application;

[0034] Figure 8 A cross-sectional schematic diagram of a radiation detector provided in some other embodiments of the present application;

[0035] Fig. 9 Schematic cross-sectional views of radiation detectors provided in some other embodiments of the present application.

[0036] The figures are as follows:

[0037] Photosensitive structure 10; first electrode 11; photosensitive layer 12; second electrode 13; first carrier layer 14; second carrier layer 15; buffer layer 16; first sub-buffer layer 161; second sub-buffer layer 162; third sub-buffer layer 163; fourth sub-buffer layer 164; array substrate 20; substrate 21; transistor 22; packaging structure 30; first packaging layer 31; second packaging layer 32; third packaging layer 33. DETAILED DESCRIPTION

[0038] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0039] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0040] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0041] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0042] See also Figure 1In a first aspect, the present application provides a radiation detector, including a photosensitive structure 10, wherein the photosensitive structure 10 includes a first electrode 11, a photosensitive layer 12, and a second electrode 13 stacked in sequence. The photosensitive structure 10 can detect external light, for example, X-rays. When the photosensitive layer 12 is irradiated by radiation, it can separate electron-hole pairs, and under the action of an external electric field, the electrons and holes can move toward the first electrode 11 and the second electrode 13 respectively to form a current, so that a corresponding radiation image can be formed by digitizing the electrical signal corresponding to the current.

[0043] See also Figure 2 , the photosensitive structure 10 may further include a first carrier layer 14 and a second carrier layer 15, wherein the first carrier layer 14 is disposed between the first electrode 11 and the photosensitive layer 12, and the second carrier layer 15 is disposed between the second electrode 13 and the photosensitive layer 12, that is, in the photosensitive structure 10, the first electrode 11, the first carrier layer 14, the photosensitive layer 12, the second carrier layer 15, and the second electrode 13 are sequentially stacked. It should be noted that the first electrode 11, the first carrier layer 14, the photosensitive layer 12, the second carrier layer 15, and the second electrode 13 may be sequentially stacked from top to bottom, or may be sequentially stacked from bottom to top. The embodiment of the present application is described by taking the first electrode 11, the first carrier layer 14, the photosensitive layer 12, the second carrier layer 15, and the second electrode 13 as an example of sequentially stacking from bottom to top. When the photosensitive layer 12 is irradiated by radiation and separates electron-hole pairs, and the electrons and holes move toward the first electrode 11 and the second electrode 13 respectively under the action of the external electric field, the first carrier layer 14 can transfer carriers between the first electrode 11 and the photosensitive layer 12, and the second carrier layer 15 can transfer carriers between the second electrode 13 and the photosensitive layer 12, thereby improving the migration speed of the carriers to a certain extent. Optionally, the first carrier layer 14 can be used to transmit any one of the electrons and holes, and the second carrier layer 15 is used to transmit the other. In the embodiment of the present application, the first carrier layer 14 transmits holes and the second carrier layer 15 transmits electrons as an example. It can be understood that in the process of the first carrier layer 14 transmitting holes and / or the second carrier layer 15 transmitting electrons, subject to the migration speed of the carriers, the first carrier layer 14 and / or the second carrier layer 15 usually produce recombination of electrons and holes, thereby affecting the performance of the radiation detector.

[0044] Therefore, in this embodiment, by setting a buffer layer 16 on at least one side of the first carrier layer 14 and / or the second carrier layer 15, and along the direction away from the photosensitive layer 12, the energy level of each film layer in the photosensitive structure 10 gradually increases, so that the energy level of the buffer layer 16 is between the energy levels of its two adjacent film layers, so that the buffer layer 16 can increase the carrier migration speed between the first carrier layer 14 and / or the second carrier layer 15 and the adjacent film layer, so as to reduce the carrier recombination rate of the first carrier layer 14 and / or the second carrier layer 15, thereby improving the performance of the radiation detector.

[0045] It should be noted that the energy level of each film layer in the photosensitive structure 10 gradually increases in the direction away from the photosensitive layer 12, which means that among the three film layers, the energy level of the middle film layer is greater than the valence band energy level of the film layer close to the photosensitive layer 12, and is less than the conduction band energy level of the film layer away from the photosensitive layer 12. Exemplarily, when the buffer layer 16 is disposed between the second carrier layer 15 and the second electrode 13, the energy level of the buffer layer 16 is greater than the valence band energy level of the second carrier layer 15, and is less than the energy level of the second electrode 13, so that the buffer layer 16 can accelerate the migration speed of carriers.

[0046] In some optional embodiments, the radiation detector may include a power supply and a first signal line and a second signal line connected to the power supply, the first signal line is electrically connected to the first electrode 11, and the second signal line is electrically connected to the second electrode 13, so as to apply current to the first electrode 11 and the second electrode 13 to form an external electric field.

[0047] See also Figure 3 In some embodiments, the radiation detector further includes an array substrate 20, the array substrate 20 includes a substrate 21 and a driving circuit disposed on one side of the substrate 21, the photosensitive structure 10 is disposed on one side of the substrate 21, and the driving circuit is electrically connected to the first electrode 11 and the second electrode 13 of the photosensitive structure 10 respectively.

[0048] In these embodiments, the driving circuit may include a transistor 22 and a storage capacitor, and the storage capacitor includes a first electrode and a second electrode. The driving circuit is electrically connected to the first electrode 11 and the second electrode 13 of the photosensitive structure 10, respectively. Therefore, when the photosensitive layer 12 is irradiated by radiation and the electron-hole pairs are separated, a current is applied to the first electrode 11 and the second electrode 13 through the driving circuit to form an external electric field, so that the electrons and holes can move toward the first electrode 11 and the second electrode 13 under the action of the external electric field. In addition, the photosensitive structure 10 and the driving circuit are both arranged on one side of the substrate 21, so that the path between the driving circuit and the first electrode 11 and the path between the driving circuit and the second electrode 13 can be shortened, thereby improving the response speed of the radiation detector.

[0049] It should be noted that when the photosensitive structure 10 is set on one side of the substrate 21, the first electrode 11, the first carrier layer 14, the photosensitive layer 12, the second carrier layer 15 and the second electrode 13 can be stacked in sequence in a direction away from the substrate 21, and the driving circuit can be located between the photosensitive structure 10 and the substrate 21.

[0050] Preferably, the photosensitive structure 10 is located on the side of the driving circuit away from the substrate 21, thereby reducing the shielding of light by the driving circuit, so that the photosensitive layer 12 of the photosensitive structure 10 can better receive external light and separate electron-hole pairs.

[0051] In some embodiments, the driving circuit includes a transistor 22, and the array substrate 20 also includes an insulating layer located on the side of the transistor 22 away from the substrate, the insulating layer has a via, and the first electrode 11 is located on the side of the insulating layer away from the substrate 21 and is connected to the transistor 22 through the via.

[0052] In these embodiments, a via hole is formed in the insulating layer so that the first electrode 11 passes through the via hole and is connected to the transistor 22, thereby realizing electrical connection between the driving circuit and the first electrode 11. Specifically, the transistor 22 may include an active layer, a source electrode, a drain electrode, and a gate electrode, and the first electrode 11 may be connected to the source electrode or the drain electrode through the via hole 24, so that current is applied to the first electrode 11 through the source electrode or the drain electrode.

[0053] See also Figure 4 In some embodiments, there are multiple photosensitive structures 10, and the multiple photosensitive structures 10 are distributed in a direction parallel to the substrate 21. There are multiple driving circuits of the array substrate 20, and the multiple driving circuits are connected one-to-one to the first electrodes 11 and the second electrodes 13 of the multiple photosensitive structures 10.

[0054] In these embodiments, by providing multiple photosensitive structures 10 to sense radiation, the radiation sensing effect can be improved, thereby improving the clarity and pixels of the formed radiation image. Multiple driving circuits are connected one-to-one to the first electrodes 11 and the second electrodes 13 of the multiple photosensitive structures 10, that is, multiple driving circuits drive the multiple photosensitive structures 10 one-to-one, which can further improve the response speed of the radiation detector compared to driving multiple photosensitive structures 10 simultaneously through one driving circuit.

[0055] In some optional embodiments, two adjacent photosensitive structures 10 may be spaced apart to reduce mutual interference.

[0056] In some embodiments, the material of the photosensitive layer 12 includes a perovskite material, thereby improving the photoelectric conversion efficiency of the photosensitive layer 12 and reducing the cost.

[0057] Optionally, the photosensitive layer 12 may include a single perovskite material, that is, ABX3. The A position is usually composed of Cs + , Rb + Monovalent metal ions or CH3NH3 + , HC(NH2)2 and other organic molecular chains; the B position is usually Pb 2+ Sn 2+ ,Ge 2+ The X position is usually composed of Cl - Br - ,I - For example, Figure 5 As shown, the photosensitive layer 12 may be APbX3, wherein an organic molecular chain is used as an A-site ion and Pb 2+ As the B-site ion, Pb 2+ The performance of the photosensitive layer 12 can be improved, for example, the stability, reliability and photoelectric properties of the photosensitive layer 12 can be improved.

[0058] Preferably, the material of the photosensitive layer 12 includes a non-lead-based perovskite material, so that the toxicity in the photosensitive layer 12 can be reduced, making the radiation detector environmentally friendly. + 、Ag + 、Na + , K + 、In + Monovalent metal particles and In 3+ 、Bi 3+ , Sb 3+ Replace the Pb at the B position with a trivalent metal ion 2+ , forming a double perovskite material.

[0059] In some embodiments, the material of the photosensitive layer 12 includes a double-layer perovskite material and / or a triple-layer perovskite material.

[0060] It is understandable that if Figure 6 As shown, in the related art, a radiation detector can usually generate a photosensitive layer 12 made of a single crystal perovskite material on a substrate 21. In order to increase the ion activation energy, improve the ion movement phenomenon, and reduce the dark current of the device, the surface of the single crystal perovskite material is usually passivated and modified. However, the effect of the single crystal perovskite material after the passivation modification on improving the dark current is limited. Moreover, in the related art, in order to increase the absorption of radiation, it is usually necessary to prepare the photosensitive layer 12 over a large area, which leads to an increase in the voids and grain boundary defects in the photosensitive layer 12 and a more obvious ion movement phenomenon.

[0061] Therefore, in this embodiment, by setting the material of the photosensitive layer 12 to include a double-layer perovskite material and / or a triple-layer perovskite material, compared to setting the material of the photosensitive layer 12 to include a single crystal perovskite material, the crystal density can be increased, the ion channel can be reduced, the crystallinity and stability of the photosensitive layer 12 can be improved, and the impact resistance and radiation resistance of the device can be improved without passivation modification treatment on the surface of the photosensitive layer 12, and the area of ​​the photosensitive layer 12 can be reduced accordingly.

[0062] Preferably, the material of the photosensitive layer 12 includes A2B1B2X6, A3B2 III X9 and A2B IV At least one of X6 is to reasonably set the material of the photosensitive layer 12 to improve the performance of the radiation detector while reducing the cost.

[0063] It should be noted that in A2B1B2X6, B1 and B2 are two different monovalent ions located at the B position; A3B2 III X9, B2 III It can be two trivalent ions located at the B position; A2B IV X6, B IV It can be a tetravalent ion located at the B position. Figure 7 As shown, monovalent ions (M + ), trivalent ions (M 3+ ), tetravalent ions (M 4+ ) replaces the original divalent ions at the B site to form a double perovskite structure or a triple perovskite structure.

[0064] In some embodiments, the material of the second carrier layer 15 includes a P-type material, and the material of the first carrier layer 14 includes an N-type material, so that the holes generated by the photosensitive layer 12 are transmitted through the second carrier layer 15, and the electrons generated by the photosensitive layer 12 are transmitted through the first carrier layer 14, which can accelerate the transmission of carriers and reduce leakage current.

[0065] It should be noted that when the material of the second carrier layer 15 includes a P-type material and the material of the first carrier layer 14 includes an N-type material, a PIN structure may be formed in the photosensitive structure 10 .

[0066] Preferably, the P-type material and / or the N-type material includes one of an inorganic oxide and a perovskite material, so that the performance of the radiation detector can be improved by reasonably selecting the P-type material and / or the N-type material.

[0067] It should be noted that the P-type material and / or the N-type material is preferably a perovskite material, so that it is easy to adjust the band gap matching, improve the carrier transmission efficiency, and optimize the carrier migration performance.

[0068] Preferably, the perovskite material comprises an inorganic perovskite material and / or an organic-inorganic perovskite material.

[0069] In these embodiments, the inorganic perovskite material has a stable crystal structure and a high carrier mobility, which contributes to the efficient migration of carriers. The organic-inorganic perovskite material has the advantages of both organic and inorganic materials, which can further improve the mobility of carriers. Therefore, by setting the perovskite material to include an inorganic perovskite material and / or an organic-inorganic perovskite material, the materials of the first carrier layer 14 and the second carrier layer 15 can be reasonably set to improve the performance of the first carrier layer 14 and the second carrier layer 15.

[0070] Please continue reading Figure 2 In some embodiments, the buffer layer 16 includes a first sub-buffer layer 161, which is disposed between the second electrode 13 and the second carrier layer 15, and an energy level of the first sub-buffer layer 161 is greater than an energy level of the second carrier layer 15 and less than an energy level of the second electrode 13.

[0071] In these embodiments, a first sub-buffer layer 161 is provided between the second electrode 13 and the second carrier layer 15 so that the energy level of the first sub-buffer layer 161 is greater than the energy level of the second carrier layer 15 and less than the energy level of the second electrode 13, thereby increasing the carrier migration speed between the second carrier layer 15 and the second electrode 13, reducing the probability of carrier recombination between the second carrier layer 15 and the second electrode 13, and improving the performance of the radiation detector.

[0072] Preferably, the material of the first sub-buffer layer 161 includes ytterbium and / or aluminum, so that the energy level of the first sub-buffer layer 161 is between the energy level of the first carrier layer 14 and the energy level of the first electrode 11 .

[0073] See also Figure 8 In some optional embodiments, the buffer layer 16 may further include a second sub-buffer layer 162, which is disposed between the photosensitive layer 12 and the second carrier layer 15. The energy level of the second sub-buffer layer 162 is greater than the energy level of the photosensitive layer 12 and less than the energy level of the second carrier layer 15, thereby improving the carrier migration speed between the photosensitive layer 12 and the second carrier layer 15.

[0074] Please continue reading Figure 8 In some optional embodiments, the buffer layer 16 may further include a third sub-buffer layer 163, which is disposed between the photosensitive layer 12 and the first carrier layer 14. The energy level of the third sub-buffer layer 163 is greater than the energy level of the photosensitive layer 12 and less than the energy level of the first carrier layer 14, thereby improving the carrier migration speed between the photosensitive layer 12 and the first carrier layer 14.

[0075] Please continue reading Figure 8 In some optional embodiments, the buffer layer 16 may further include a fourth sub-buffer layer 164, which is disposed between the first carrier layer 14 and the first electrode 11. The energy level of the third sub-buffer layer 163 is greater than the energy level of the first carrier layer 14 and less than the energy level of the first electrode 11, thereby increasing the carrier migration speed between the first carrier layer 14 and the first electrode 11.

[0076] See also Fig. 9 In some embodiments, the radiation detector further includes a packaging structure 30 , the packaging structure 30 includes a first packaging layer 31 , and the first packaging layer 31 is disposed to cover the photosensitive structure 10 .

[0077] The first encapsulation layer 31 covers the photosensitive structure 10, which can protect the photosensitive structure 10 from the influence of the external environment, prevent air and moisture from penetrating into the radiation detector, and extend the service life and stability of the radiation detector. The first encapsulation layer 31 can also prevent impurities and harmful substances from entering the radiation detector, thereby ensuring the performance and quality of the detector.

[0078] Preferably, the material of the first encapsulation layer 31 includes an inorganic material. For example, the first encapsulation layer 31 may be made of silicon oxide, silicon nitride or silicon oxynitride, etc., which can provide good mechanical support and encapsulation protection.

[0079] Please continue reading Fig. 9 In some embodiments, the packaging structure 30 further includes a second packaging layer 32, which is disposed on a side of the first packaging layer 31 away from the photosensitive structure 10, thereby further isolating external moisture, oxygen, etc. from entering the interior of the radiation detector.

[0080] Preferably, the material of the second encapsulation layer 32 includes an organic material. The second encapsulation layer 32 can be made of an organic material such as a polymer, which has stronger flexibility, so that it can better adapt to the bending of the radiation detector and can also play a role in buffering external forces.

[0081] Furthermore, the thickness of the second encapsulation layer 32 may be greater than the thickness of the first encapsulation layer 31 to further improve the encapsulation effect.

[0082] Please continue reading Fig. 9 Preferably, the encapsulation structure 30 further includes a third encapsulation layer 33 , and the third encapsulation layer 33 is disposed on a side of the second encapsulation layer 32 away from the photosensitive structure 10 .

[0083] The third encapsulation layer 33 is arranged on the side of the second encapsulation layer 32 away from the photosensitive structure 10, which can further improve the encapsulation effect of the radiation detector. In addition, the first encapsulation layer 31 and the third encapsulation layer 33 can surround the second encapsulation layer 32 to prevent overflow of the second encapsulation layer 32 to ensure the reliability of the encapsulation.

[0084] Preferably, the material of the third encapsulation layer 33 includes an inorganic material. For example, the third encapsulation layer 33 may be made of silicon oxide, silicon nitride or silicon oxynitride, etc., which can provide good mechanical support and encapsulation protection.

[0085] Although the embodiments disclosed in this application are as above, the contents described are only embodiments adopted for facilitating the understanding of this application and are not intended to limit the present invention. Any technician in the technical field to which this application belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in this application, but the scope of protection of this application shall still be subject to the scope defined in the attached claims.

[0086] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the replacement of other connection methods described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A radiation detector, characterized in that: The invention comprises a photosensitive structure, wherein the photosensitive structure comprises: A first electrode, a first carrier layer, a photosensitive layer, a second carrier layer and a second electrode are sequentially stacked; and A buffer layer, disposed on at least one side of the first carrier layer and / or the second carrier layer, for increasing the migration speed of carriers; Wherein, along the direction away from the photosensitive layer, the energy level of each film layer in the photosensitive structure gradually increases.

2. The radiation detector according to claim 1, characterized in that: The radiation detector further includes an array substrate, the array substrate includes a substrate and a driving circuit arranged on one side of the substrate, the photosensitive structure is arranged on one side of the substrate, and the driving circuit is electrically connected to the first electrode and the second electrode of the photosensitive structure respectively; Preferably, the photosensitive structure is located on a side of the driving circuit facing away from the substrate.

3. The radiation detector according to claim 2, characterized in that: The driving circuit includes a transistor, and the array substrate also includes an insulating layer located on a side of the transistor away from the substrate, the insulating layer is provided with a via, and the first electrode is located on a side of the insulating layer away from the substrate and is connected to the transistor through the via.

4. The radiation detector according to claim 2, characterized in that: There are multiple photosensitive structures, and the multiple photosensitive structures are distributed in a direction parallel to the substrate. There are multiple driving circuits on the array substrate, and the multiple driving circuits are connected one-to-one to the first electrodes and the second electrodes of the multiple photosensitive structures.

5. The radiation detector according to claim 1, characterized in that: The material of the photosensitive layer includes a perovskite material; Preferably, the material of the photosensitive layer includes a non-lead-based perovskite material.

6. The radiation detector according to claim 5, characterized in that: The material of the photosensitive layer includes a double-layer perovskite material and / or a triple-layer perovskite material; Preferably, the material of the photosensitive layer includes A2B1B2X6, A3B2 III X9 and A2B IV At least one of X6.

7. The radiation detector according to claim 1, characterized in that: The material of the second carrier layer includes a P-type material, and the material of the first carrier layer includes an N-type material; Preferably, the P-type material and / or the N-type material comprises one of an inorganic oxide and a perovskite material; Preferably, the perovskite material comprises an inorganic perovskite material and / or an organic-inorganic perovskite material.

8. The radiation detector according to claim 7, characterized in that: The buffer layer comprises a first sub-buffer layer, the first sub-buffer layer is arranged between the second electrode and the second carrier layer, and the energy level of the first sub-buffer layer is greater than the energy level of the second carrier layer and less than the energy level of the second electrode; Preferably, the material of the first sub-buffer layer includes ytterbium and / or aluminum.

9. The radiation detector according to claim 1, characterized in that: The radiation detector further comprises a packaging structure, wherein the packaging structure comprises a first packaging layer, and the first packaging layer covers the photosensitive structure; Preferably, the material of the first encapsulation layer includes an inorganic material.

10. The radiation detector according to claim 9, characterized in that: The packaging structure further includes a second packaging layer, which is arranged on a side of the first packaging layer away from the photosensitive structure; Preferably, the material of the second encapsulation layer includes an organic material; Preferably, the encapsulation structure further comprises a third encapsulation layer, and the third encapsulation layer is arranged on a side of the second encapsulation layer away from the photosensitive structure; Preferably, the material of the third encapsulation layer includes inorganic material.

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