Perovskite material layer and preparation method thereof, photoconductive structure, diode and detector

Abstract

The invention discloses a perovskite material layer and a preparation method thereof, a photoconductive structure, a diode and a detector. The preparation method comprises the following steps: coating a perovskite precursor solution on a substrate to form a perovskite wet film; performing primary annealing treatment on the perovskite wet film to obtain a wet film to be treated; and carrying out imprint patterning treatment on the wet film to be treated, and carrying out any one of non-annealing vacuum auxiliary treatment and two-stage annealing treatment to obtain a perovskite material layer with a patterned surface. According to the method, the consistency of the size, the shape and the arrangement height of each pixel can be ensured, the product quality stability is ensured to a great extent, the problem that the surface of the perovskite thick film is difficult to pattern is solved, and the surface-patterned perovskite thick film X-ray detector prepared by the wet film imprinting technology has the advantages of high resolution, high resolution and the like. Leakage of light or electric signals among pixels is effectively limited, charge crosstalk is reduced, and the imaging capacity of the device is enhanced.

Description

Technical Field

[0001] This application relates to the field of perovskite material technology, and in particular to a perovskite material layer and its preparation method, a photoconductive structure, a diode, and a detector. Background Technology

[0002] In recent years, perovskite materials have shown great application potential in X-ray detection due to their advantages such as high X-ray absorption coefficient, high carrier mobility, high sensitivity, and low detection limit. Currently, photolithography is commonly used to pattern perovskite material surfaces. However, further patterning using photolithography still presents the following problems:

[0003] (1) Perovskite materials are very sensitive to moisture and oxygen and are prone to degradation. Moreover, some perovskite materials will degrade or undergo phase transformation under ultraviolet light. Environmental factors such as chemicals commonly used in photolithography (such as developer and etchant) and ultraviolet light may damage the perovskite structure.

[0004] (2) Perovskite materials are sensitive to temperature. High temperatures may cause structural changes or decomposition. High-temperature steps involved in photolithography may cause irreversible damage to perovskite.

[0005] (3) The surface of the perovskite material layer may not be smooth enough, which will affect the adhesion of the photoresist on its surface and the quality of patterning. Surface defects or inhomogeneities may affect the accuracy of the final pattern.

[0006] (4) Traditional photoresists and other photolithography auxiliary materials may be incompatible with perovskite materials, leading to patterning failure or reduced device performance. Summary of the Invention

[0007] In view of this, this application provides a perovskite material layer and its preparation method, a photoconductive structure, a diode and a detector, which overcomes the problem of the difficulty in patterning the surface of the perovskite material layer, effectively limits the leakage of light or electrical signals between pixels and reduces charge crosstalk.

[0008] According to the first aspect of this application, a method for preparing a patterned perovskite material layer is provided, comprising:

[0009] The perovskite precursor solution is coated onto the substrate to form a perovskite wet film.

[0010] The perovskite wet film is subjected to a first-stage annealing treatment to obtain the wet film to be treated;

[0011] The wet film to be processed is subjected to an imprint patterning process, and either a vacuum-assisted process without annealing or a two-stage annealing process to obtain a perovskite material layer with a surface pattern.

[0012] Optionally, the imprinting patterning process on the wet film to be processed, and any one of the non-annealing vacuum-assisted processing and two-stage annealing processing, includes:

[0013] The wet film to be processed is subjected to embossing patterning while simultaneously undergoing vacuum-assisted processing without annealing; or,

[0014] The wet film to be processed is subjected to embossing patterning while undergoing two-stage annealing; or,

[0015] After the imprinting patterning process of the wet film to be processed is completed, the wet film to be processed is subjected to a two-stage annealing process.

[0016] Optionally, the annealing temperature of the first-stage annealing process is 50℃~130℃, and the annealing time is 10min~4h.

[0017] Optionally, the non-annealing vacuum-assisted treatment time is 10 min to 4 h.

[0018] Optionally, the annealing temperature of the two-stage annealing process is 80℃~120℃, and the annealing time is 5h~10h.

[0019] Optionally, the imprinting patterning process on the wet film to be processed includes:

[0020] The wet film to be treated is pressed with pressure using a preset pattern template, wherein the pressing pressure is 100 kPa to 1 MPa and the pressing time is 10 min to 4 h.

[0021] Optionally, the method for preparing the perovskite material layer further includes:

[0022] According to a second aspect of this application, a perovskite material layer is provided, which is prepared by the above-described method for preparing a patterned perovskite material layer.

[0023] According to a third aspect of this application, a photoconductive structure is provided, comprising a conductive substrate stacked sequentially from bottom to top, a perovskite thick film prepared by the above-described method for preparing patterned perovskite material layers, and an electrode.

[0024] According to a fourth aspect of this application, a photodiode is provided, comprising: an NIP type photodiode or a PIN type photodiode;

[0025] The NIP type photodiode includes a conductive substrate, an electron transport layer, a perovskite thick film prepared by the above-described method for preparing patterned perovskite material layers, a hole transport layer, and an electrode, which are stacked sequentially from bottom to top.

[0026] The PIN photodiode includes a conductive substrate, a hole transport layer, a perovskite thick film prepared by the above-described method for preparing patterned perovskite material layers, an electron transport layer, and an electrode, which are stacked sequentially from bottom to top.

[0027] The thickness of the perovskite thick film is 50 μm to 800 μm, the thickness of the hole transport layer is 15 nm to 50 nm, and the thickness of the electrode is 80 nm to 600 nm.

[0028] According to a fifth aspect of this application, a photodiode is provided, comprising: an NIP type photodiode or a PIN type photodiode;

[0029] The NIP type photodiode includes, from bottom to top, a conductive substrate, an electron transport layer, an interface modification layer, a perovskite thick film prepared by the above-mentioned method for preparing patterned perovskite material layers, a hole transport layer, and an electrode, which are stacked and connected sequentially.

[0030] The PIN photodiode includes, from bottom to top, a conductive substrate, a hole transport layer, a perovskite thick film prepared by the above-described method for preparing patterned perovskite material layers, an electron transport layer, an interface modification layer, and an electrode, which are stacked and connected sequentially.

[0031] The thickness of the perovskite thick film is 50 μm to 800 μm, the thickness of the hole transport layer is 15 nm to 50 nm, the thickness of the electrode is 80 nm to 600 nm, and the thickness of the interface modification layer is 1 nm to 10 nm.

[0032] According to a sixth aspect of this application, a radiation detector is provided, including the aforementioned photoconductive structure and the aforementioned photodiode.

[0033] Optionally, the hole transport layer in the photodiode is made of at least one material selected from 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobisfluorene, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, nickel oxide, copper thiocyanate, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and polyvinylcarbazole;

[0034] The electron transport layer in the photodiode is made of at least one material selected from fullerene, fullerene derivatives, tin oxide, titanium dioxide, and zinc oxide.

[0035] The interface modification layer in the photodiode is made of at least one material selected from lithium fluoride, lithium oxide, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and molybdenum trioxide.

[0036] The electrodes in the photoconductive structure or the photodiode are made of at least one material selected from gold, silver, copper, and carbon.

[0037] Using the above technical solution, a perovskite wet film coated on a substrate is first subjected to an annealing process. This causes partial evaporation of the solvent in the perovskite wet film, reducing its fluidity and initially forming the perovskite film structure (the wet film to be treated). This ensures the wet film reaches the wet film imprinting state, preventing deformation during subsequent pattern printing. The desired pattern is then imprinted onto the wet film using an imprinting process, creating a surface-patterned wet film. Compared to traditional complex processes such as photolithography, the imprinting process does not require complex photochemical processes or multi-step etching operations, avoiding the adverse effects of the photolithography environment on the perovskite structure. This reduces manufacturing costs while further improving pattern accuracy. Finally, a two-stage annealing process or a vacuum-assisted process without annealing completes solvent evaporation and perovskite grain growth, resulting in a surface-patterned perovskite material layer. This ensures that the size, shape, and arrangement of each pixel in the perovskite material layer are highly consistent, greatly guaranteeing the quality stability of the perovskite material layer. In turn, it reduces charge crosstalk between multiple pixels caused by photolithography, improves the imaging capability of the device, and greatly promotes the application of perovskite materials in the field of X-ray imaging.

[0038] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0039] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0040] Figure 1 A schematic flowchart of the method for preparing a patterned perovskite material layer according to an embodiment of this application is shown;

[0041] Figure 2 A schematic diagram of the photoconductive structure according to an embodiment of this application is shown;

[0042] Figure 3 A schematic diagram of the structure of a NIP-type photodiode according to an embodiment of this application is shown;

[0043] Figure 4 A schematic diagram of the structure of a PIN photodiode according to an embodiment of this application is shown;

[0044] Figure 5An optical microscope image of the surface of the patterned perovskite material layer according to an embodiment of this application is shown;

[0045] Figure 6 A comparative schematic diagram of the device under different irradiation conditions according to embodiments of this application is shown;

[0046] Figure 7 The current-voltage curve of the X-ray detector according to an embodiment of this application is shown;

[0047] Figure 8 A schematic diagram of the sensitivity of an X-ray detector according to an embodiment of this application is shown;

[0048] Figure 9 An X-ray diffraction pattern of an X-ray detector according to an embodiment of this application is shown.

[0049] The above figures include the following reference numerals:

[0050] 11 Metal electrode, 12 Perovskite thick film, 13 Conductive substrate, 14 Hole transport layer, 15 Interface modification layer, 16 Electron transport layer. Detailed Implementation

[0051] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0052] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0053] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “attached” to another element, it can be directly connected or attached to the other element, or there may be intermediate elements. Furthermore, “connected” or “attached” as used herein can include wireless connections or wireless interconnections. The term “and / or” as used herein includes all or any unit and all combinations of one or more associated listed items.

[0054] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art.

[0055] This embodiment provides a method for preparing a perovskite material layer, such as... Figure 1 As shown, the method includes:

[0056] Step 101: Coat the perovskite precursor solution onto the substrate to form a perovskite wet film.

[0057] The general structural formula of perovskite materials is ABX3, where A includes substituted or unsubstituted ammonium ions, substituted or unsubstituted ether ions, and Cs. + 、Rb + Li + and Na + The group consists of monovalent cations; B includes Ca 2+ 、Sr 2+ Cd 2+ Cu 2 + Ni 2+ Mn 2+ Fe 2+ Co 2+ Pd 2+ 、Ge 2+ Sn 2+ Pb 2+ Yb 2+ and / or Eu 2+ The group consists of divalent cations; X includes F - Cl - ,Br - I - SCN - and / or OCN - The monovalent anions formed by these.

[0058] Specifically, the perovskite precursor solution can be a slurry with low fluidity formed by mixing perovskite powder with organic solvent and polymer monomer, or it can be a colloidal solution with high fluidity formed by dissolving perovskite powder in organic solvent.

[0059] It is understood that the perovskite precursor solution can be coated onto the substrate in the following manner:

[0060] Method 1: Scraping method.

[0061] Specifically, a perovskite precursor solution is placed on a substrate, and a doctor blade is brought into contact with the substrate at a specific angle. The doctor blade is moved across the substrate in a specific direction (such as transverse or longitudinal) to spread the perovskite precursor solution. During the coating process, multiple repetitions may be required to achieve the desired thickness, and the pressure, angle, and movement speed of the doctor blade must be controlled to ensure coating uniformity. This method is simple to operate and inexpensive.

[0062] Method 2: Spin coating.

[0063] Specifically, the substrate is first fixed on the rotating stage of a spin coater, and a small amount of perovskite precursor solution is precisely dropped onto the center of the substrate. Then, the rotation speed and time parameters of the spin coater are set, for example, 1000 r / min to 5000 r / min, with a rotation time of 10 s to 60 s. After starting the spin coater, as the substrate rotates, the perovskite precursor solution rapidly diffuses towards the edge of the substrate under centrifugal force until a uniform perovskite wet film is formed. This ensures the uniform distribution of the perovskite precursor solution on the substrate, guaranteeing the uniformity of the perovskite wet film thickness and enabling the fabrication of thinner film structures.

[0064] It should be noted that, in order to prepare thicker perovskite films, a perovskite precursor solution with higher viscosity can be used as a raw material, or spin coating can be performed at a lower rotation speed.

[0065] Method 3: Vibration casting method.

[0066] Specifically, the perovskite slurry is poured onto a substrate, which is then transferred to a vibration table. The vibration frequency and duration of the table are set, for example, a frequency of 50Hz to 150Hz and a duration of 1min to 10min. Vibration is then initiated. During continuous vibration, the perovskite precursor solution can level out, eliminating air bubbles and thus reducing voids in the final perovskite wet film, thereby improving tap density and uniformity.

[0067] Method 4: Spraying.

[0068] Specifically, the perovskite precursor solution is sprayed from the initial position of the substrate through a nozzle, and the spraying is repeated multiple times to prepare a perovskite wet film. This allows for better control over the density and thickness of the perovskite wet film.

[0069] Step 102: Perform a first-stage annealing treatment on the perovskite wet film to obtain the wet film to be treated.

[0070] In this embodiment, the perovskite wet film is first annealed at a lower temperature or for a shorter time. This causes partial evaporation of the solvent in the perovskite wet film, reducing its fluidity and initially forming the perovskite film structure (the wet film to be treated). This ensures that the wet film reaches the wet film imprinting state, avoiding the phenomenon of flow and diffusion at the edges of the pattern caused by the highly fluid precursor liquid failing to stabilize quickly after imprinting. This helps reduce pattern bending or distortion and improves pattern clarity and quality.

[0071] One stage of the annealing process involves annealing at temperatures ranging from 50℃ to 130℃, for example, 65℃, 85℃,

[0072] Annealing temperatures are 100℃ and 125℃; annealing time ranges from 10 minutes to 4 hours, for example, 30 minutes, 60 minutes, or 150 minutes.

[0073] 200min.

[0074] Step 103: Perform an imprint patterning process on the wet film to be processed, and perform either a vacuum-assisted process without annealing or a two-stage annealing process to obtain a perovskite material layer with a patterned surface.

[0075] The processing time for vacuum-assisted treatment without annealing is 10 min to 4 h, for example, 60 min, 150 min, or 200 min. The annealing temperature for two-stage annealing is 80℃ to 120℃, for example, 90℃, 105℃, or 110℃; the annealing time is 5 h to 10 h, for example, 6 h, 7.5 h, or 9 h.

[0076] In this embodiment, after a first-stage annealing process, the desired pattern is imprinted onto the wet film to be treated using an imprinting method, thus preparing a surface-patterned wet film. Compared with traditional complex processes such as photolithography, the imprinting process does not require complex photochemical processes or multi-step etching operations, avoiding the adverse effects of the photolithography environment on the perovskite structure. This reduces fabrication costs while further improving pattern accuracy. Finally, a second-stage annealing process or a vacuum-assisted process without annealing is used to complete solvent evaporation and perovskite grain growth, resulting in a surface-patterned perovskite material layer. This ensures that the size, shape, and arrangement height of each pixel in the perovskite material layer are consistent, greatly guaranteeing the quality stability of the perovskite material layer. This reduces charge crosstalk between multiple pixels caused by photolithography, improves device imaging capabilities, and greatly promotes the application of perovskite materials in the field of X-ray imaging.

[0077] It is worth mentioning that the thickness of the perovskite material layer prepared by the method of this application can be adjusted according to requirements, and the embodiments of this application do not impose specific limitations. For example, when applied to X-ray detectors, thick films of 30 μm to 800 μm can be prepared, and when applied to solar cells, thin films of 100 nm to 1000 nm can be prepared.

[0078] In practical applications, the wet film to be processed is patterned by imprinting, including: applying pressure to the wet film to be processed with a preset pattern template for imprinting.

[0079] In this embodiment, the pattern is printed using an imprinting method, which can accurately replicate the micro-nano scale pattern on the template onto the target substrate, achieving high-precision pattern transfer. Furthermore, the equipment and steps required for printing are simpler and the cost is lower, making it suitable for mass production and significantly improving production efficiency. In addition, by changing the imprinting template, it is possible to quickly adapt to different design requirements, achieving diverse pixel structures and functions to meet the market demand for customized products.

[0080] It is worth mentioning that the imprinting pressure should be controlled within the range of 100 kPa to 1 MPa, for example, 300 kPa, 500 kPa, and 800 kPa; the imprinting time should be controlled within the range of 10 min to 2 h, for example, 30 min, 60 min, and 100 min. Generally, the higher the pressure, the shorter the imprinting time. If the imprinting pressure is too high or the imprinting time is too long, the wet film to be processed may overfill the uneven structure of the template, leading to difficulties in demolding, and may even damage the template or film; if the imprinting force is too low or the imprinting time is too short, it may not be able to completely fill the pattern of the template, resulting in an incomplete pattern.

[0081] In one embodiment, the wet film to be treated can be simultaneously subjected to imprinting patterning and anneal-free vacuum-assisted processing. This combines a vacuum environment with pattern imprinting, accelerating solvent evaporation from the wet film under vacuum conditions, reducing the solvent molecule content in the film, while simultaneously imprinting the pattern. This allows for better control of crystal growth direction and morphology, significantly improving crystallization quality. Furthermore, while ensuring complete solvent evaporation and promoting rapid perovskite crystal formation for more ordered crystallization, it avoids problems such as material decomposition, phase transformation, or adverse reactions with the substrate material that may occur with high-temperature annealing, thus contributing to improved perovskite material layer quality. Moreover, the anneal-free process eliminates the annealing step, resulting in lower equipment requirements, reduced energy consumption, and easier integration with other process steps.

[0082] In one embodiment, the wet film to be processed can be simultaneously subjected to imprinting patterning and two-stage annealing. On the one hand, by combining wet film imprinting with annealing, the material distribution in the wet film is simultaneously driven by the heat brought by annealing under the external force of imprinting. This allows the solvent in the perovskite wet film to evaporate uniformly during the wet film imprinting process, completing further grain growth, improving the overall quality and performance of the film, reducing local non-uniformity, and the crystal growth may have a real-time impact on the pattern being imprinted. The pattern may be fine-tuned or deformed under the heat of annealing, which is conducive to patterned structures with special optical or electrical properties. On the other hand, the preparation time of the patterned perovskite material layer can be further shortened, especially in large-scale industrial production, which can improve production efficiency and reduce production cycle.

[0083] In one embodiment, the wet film to be processed can be patterned first, and then subjected to a two-stage annealing process after patterning is completed. This alternating patterning and two-stage annealing ensures the pattern is essentially finalized before annealing. On one hand, this makes the crystal growth direction more constrained by the boundaries of the imprinted pattern structure, guaranteeing the clarity, uniformity, and film quality of the pattern. On the other hand, annealing parameters (such as temperature and time) can be adjusted for the imprinted pattern to make crystal growth in the pattern more consistent with expectations, improving pattern quality, optimizing crystal growth direction, enhancing photoelectric performance, and thus ensuring the consistency and stability of the perovskite material layer.

[0084] It should be noted that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0085] This embodiment provides a photoconductive structure, such as Figure 2 As shown, the photoconductive structure includes a conductive substrate 13, a perovskite thick film 12, and a metal electrode 11 stacked sequentially from bottom to top.

[0086] In this embodiment, a perovskite thick film is used as the photosensitive layer of the photoconductive structure to absorb photons and generate a photoconductive effect. When a photon strikes the perovskite thick film, electrons in the film absorb the photon's energy and transition from the valence band to the conduction band, thereby generating free electrons and holes, realizing the conversion of invisible radiation energy into an electrical signal. Electrodes collect free electrons and holes to form a photocurrent, which is then transmitted to an external circuit. Because the perovskite thick film prepared by the method of this application has a good crystal structure and high-quality pattern, it can provide a smooth transport channel for charge carriers, thereby improving the carrier mobility and further enhancing the photoelectric conversion efficiency and charge transport speed of the photoconductive structure, as well as the response speed and stability of the photoconductive structure.

[0087] This embodiment provides a photodiode, including: an NIP type photodiode or a PIN type photodiode.

[0088] Specifically, such as Figure 3 As shown, the NIP type photodiode includes: a conductive substrate 13, an electron transport layer 16, a perovskite thick film 12, a hole transport layer 14, and an electrode 11 stacked sequentially from bottom to top.

[0089] like Figure 4 As shown, the PIN photodiode includes a conductive substrate 13, a hole transport layer 14, a perovskite thick film 12, an electron transport layer 16, and an electrode 11, which are stacked and connected sequentially from bottom to top.

[0090] Furthermore, the thickness of the perovskite thick film is 50 μm to 800 μm, the thickness of the hole transport layer is 15 nm to 50 nm, and the thickness of the electrode is 80 nm to 600 nm.

[0091] In this embodiment, a highly dense perovskite thick film at the hundred-micrometer scale is used as the active layer. When photons strike the perovskite thick film, electrons in the film absorb the energy of the photons and transition from the valence band to the conduction band, thereby generating free electrons and holes, realizing the conversion of invisible radiation energy into electrical signals. Free electrons and holes are transported through hole transport layers and electron transport layers, respectively, improving the extraction efficiency of electrons and holes. Finally, electrons and holes are collected by electrodes to form a photocurrent, which is then transmitted to an external circuit. Because the perovskite thick film prepared by the method of this application has a good crystal structure and high-quality pattern, it can achieve sufficient absorption of radiation energy, thereby achieving good X-ray response and sensitivity, which helps to reduce charge crosstalk between multiple pixels and improve the imaging capability of the device.

[0092] In one embodiment, such as Figure 3 As shown, for NIP type photodiodes, there is also an interface modification layer 15 between the electron transport layer 16 and the perovskite thick film 12. Figure 4 As shown, for PIN photodiodes, there is also an interface modification layer 15 between the electron transport layer 16 and the electrode 11.

[0093] The thickness of the interface modification layer is 1nm to 10nm.

[0094] In this embodiment, the band alignment between adjacent layers is adjusted through an interface modification layer. This ensures that the band bending direction and degree are appropriate, promoting the separation of photogenerated carriers, reducing carrier recombination at the interface, and making the separation of electrons and holes in the junction region more efficient, thereby improving the photoelectric conversion efficiency of the photodiode. Furthermore, the interface modification layer acts as a physical and chemical barrier, preventing harmful external substances from eroding the internal functional layers and improving the stability of the photodiode under different environmental conditions.

[0095] This embodiment provides a radiation detector, which can be composed of a photoconductive structure or a photodiode.

[0096] Among them, the radiation detector is an X-ray detector, a gamma-ray detector, or an X-ray and gamma-ray detector.

[0097] In this embodiment, the perovskite thick-film radiation detector exhibits excellent charge transport performance, extremely fast response speed, and high X-ray sensitivity (greater than 5000 μC Gy). air -1 cm -2 The dark current density is between 0.1 nA / cm². 2 It exhibits good stability within the range of ~5nA / cm2 (E=0.1V / μm).

[0098] Understandably, in radiation detectors, the conductive substrate in the photoconductive structure or photodiode is conductive glass deposited with indium tin oxide and / or fluorine-doped tin dioxide; the hole transport layer in the photodiode is made of at least one material selected from 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobisfluorene, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, nickel oxide, copper thiocyanate, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and polyvinylcarbazole; the electron transport layer in the photodiode is made of at least one material selected from fullerene, fullerene derivatives, tin oxide, titanium dioxide, and zinc oxide; the interface modification layer in the photodiode is made of at least one material selected from lithium fluoride, lithium oxide, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and molybdenum trioxide; and the electrodes in the photoconductive structure or photodiode are made of at least one material selected from gold, silver, copper, and carbon.

[0099] It should be noted that, in order to achieve high-quality detection performance, radiation detectors may also include external mechanical structures such as housings and supports, and internal mechanical structures such as signal processing circuits, image processing circuits, and control circuits. Specific Implementation Example 1:

[0101] This embodiment provides an X-ray detector with a photoconductive device structure, such as... Figure 2 As shown, the photoconductive structure includes a conductive substrate 13, a perovskite thick film 12, and a metal electrode 11 stacked sequentially from bottom to top.

[0102] The photoconductive structure is prepared as follows:

[0103] S1. The transparent conductive substrate with indium tin oxide deposited is ultrasonically cleaned with deionized water, acetone and ethanol for 15 min respectively, the transparent conductive substrate is dried with nitrogen gas flow and then treated with ultraviolet ozone for 15 min.

[0104] S2. Weigh the reagents according to the molar ratio to prepare perovskite precursor slurry. Stir the slurry at 60℃ for 10h until the slurry is fully dissolved. Place the slurry in an ultrasonic bath to obtain a precursor slurry with a concentration of 6mol / L.

[0105] S3. Using a doctor blade, coat the mixed precursor slurry from step S2 onto the transparent conductive substrate from step S1 to obtain a perovskite wet film with a thickness of 800 μm. Transfer the perovskite wet film to a heating stage for pre-annealing to evaporate some of the solvent. The pre-annealing temperature is 90°C, and the pre-annealing time is 40 min, resulting in a wet film containing a small amount of solvent. Transfer the wet film containing a small amount of solvent to a pressure press, add a pattern template between the wet film and the perovskite thick film, and perform wet film imprinting. Apply an external force of 800 kPa, and imprint for 10 min to complete the pattern transfer on the surface of the wet film. Perform post-annealing simultaneously with wet film imprinting. The post-annealing temperature is 120°C, and the post-annealing time is 10 h, thereby obtaining a patterned perovskite thick film.

[0106] S4. An electrode is prepared on the perovskite thick film surface patterned in step S3 by dispensing.

[0107] like Figure 8 As shown, the highest sensitivity of the photoconductive X-ray detector prepared above is 8367.25 μCy. air -1 cm -2 As can be seen, the X-ray detector prepared in this embodiment can significantly reduce the amount of leakage current. Compared with pixels in the prior art, the amount of leakage current in each pixel of X-ray detection is significantly reduced. Specific Implementation Example 2:

[0109] This embodiment provides an X-ray detector with a photoconductive device structure, such as... Figure 2 As shown, the photoconductive structure includes a conductive substrate 13, a perovskite thick film 12, and a metal electrode 11 stacked sequentially from bottom to top.

[0110] The photoconductive structure is prepared as follows:

[0111] S1. The transparent conductive substrate with indium tin oxide deposited is ultrasonically cleaned with deionized water, acetone and ethanol for 15 min respectively, the transparent conductive substrate is dried with nitrogen gas flow and then treated with ultraviolet ozone for 15 min.

[0112] S2. Weigh the reagents according to the molar ratio to prepare perovskite precursor slurry. Stir the slurry at 60℃ for 10h until the slurry is fully dissolved. Place the slurry in an ultrasonic bath to obtain a precursor slurry with a concentration of 6mol / L.

[0113] S3. Using a doctor blade, coat the mixed precursor slurry from step S2 onto the transparent conductive substrate obtained in step S1 to obtain a perovskite wet film with a thickness of 800 μm. Transfer the perovskite wet film to a heating stage for pre-annealing to evaporate some of the solvent. The pre-annealing temperature is 90°C, and the pre-annealing time is 40 min, resulting in a wet film containing a small amount of solvent. Transfer the wet film containing a small amount of solvent to a pressure press, add a pattern template between the wet film and the perovskite thick film, and perform wet film imprinting. Apply an external force of 800 kPa for 2 h, while simultaneously placing the pressure press into a vacuum chamber for non-annealing vacuum-assisted treatment for 2 h. After completing the pattern transfer on the surface of the wet film, a patterned perovskite thick film is obtained.

[0114] S4. An electrode is prepared on the perovskite thick film surface patterned in step S3 by dispensing.

[0115] The highest sensitivity of the photoconductive X-ray detector prepared above is 7516.27 μCy. air -1 cm -2 As can be seen, the X-ray detector prepared in this embodiment can significantly reduce the amount of leakage current. Compared with pixels in the prior art, the amount of leakage current in each pixel of X-ray detection is significantly reduced. Specific Implementation Example 3:

[0117] This embodiment provides an X-ray detector with a NIP photodiode structure, such as... Figure 3 As shown, the NIP photodiode includes a conductive substrate 13, an electron transport layer 16, an interface modification layer 15, a perovskite thick film 12, a hole transport layer 14, and an electrode 11, which are stacked and connected sequentially from bottom to top.

[0118] The fabrication method of NIP photodiode is as follows:

[0119] S1. The transparent conductive substrate with indium tin oxide deposited is ultrasonically cleaned with deionized water, acetone and ethanol for 15 min respectively, the transparent conductive substrate is dried with nitrogen gas flow and then treated with ultraviolet ozone for 15 min.

[0120] S2. Weigh the pharmaceutical ingredients according to the molar ratio to prepare a perovskite precursor slurry. Stir the slurry at 60°C for 10 hours until it is fully dissolved. Then, treat the slurry with ultrasound to obtain a fine and dispersed precursor slurry with a concentration of 6 mol / L.

[0121] S3. Deposit tin oxide (SnO2) on a transparent conductive substrate to form an electron transport layer, followed by depositing an interface modification layer.

[0122] S4. Using a scraper, apply the mixed precursor slurry from step S2 onto the interface modification layer of step S1 to obtain a perovskite wet film with a thickness of 200 μm. Transfer the perovskite wet film to a heating stage for pre-annealing to evaporate some of the solvent. The pre-annealing temperature is 90°C and the pre-annealing time is 40 min, resulting in a wet film to be processed containing a small amount of solvent. Transfer the wet film to be processed containing a small amount of solvent to a pressure press, add a pattern template between the wet film and the perovskite thick film, and perform wet film imprinting. Apply an external force of 800 kPa and imprint for 10 min.

[0123] S5. After the wet film imprinting is completed, post-annealing is performed at a temperature of 120°C for 10 hours to obtain a perovskite thick film with a patterned surface.

[0124] S6. A hole transport layer is prepared by spin-coating 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobisfluorene (spiro-OMeTAD) onto a patterned perovskite thick film surface.

[0125] S7, such as Figure 5 As shown, an electrode is prepared on the surface of the hole transport layer in step S6 by dispensing.

[0126] like Figure 6 As shown, the surface-patterned NIP photodiode prepared above was applied to an X-ray detector (Example 1), and compared with an unpatterned X-ray detector as a control group (Example 2). The dark current of device II under laser irradiation was tested in devices I and III. Figure 7 As shown, when devices I and III are irradiated with laser, the dark current of device II with a patterned surface shows only a slight change compared to the dark current in the dark state, while the dark current of device II without a patterned surface shows a significant change compared to the dark current in the dark state. Therefore, it can be seen that the X-ray detector fabricated using the wet film imprinting technique greatly reduces the influence of charge crosstalk. It is evident that the surface-patterned perovskite thick-film X-ray detector fabricated in this embodiment reduces charge crosstalk between multiple pixels, improves the device's imaging capability, and greatly promotes the application of perovskite materials in the field of X-ray imaging. Specific Implementation Example 4:

[0128] This embodiment provides an X-ray detector with a NIP photodiode structure, such as... Figure 3 As shown, the NIP photodiode includes a conductive substrate 13, an electron transport layer 16, an interface modification layer 15, a perovskite thick film 12, a hole transport layer 14, and an electrode 11, which are stacked and connected sequentially from bottom to top.

[0129] The fabrication method of NIP photodiode is as follows:

[0130] S1. The transparent conductive substrate with indium tin oxide deposited is ultrasonically cleaned with deionized water, acetone and ethanol for 15 min respectively, the transparent conductive substrate is dried with nitrogen gas flow and then treated with ultraviolet ozone for 15 min.

[0131] S2. Weigh the pharmaceutical ingredients according to the molar ratio to prepare a perovskite precursor slurry. Stir the slurry at 60°C for 10 hours until it is fully dissolved. Then, treat the slurry with ultrasound to obtain a fine and dispersed precursor slurry with a concentration of 6 mol / L.

[0132] S3. Deposit tin oxide (SnO2) on a transparent conductive substrate to form an electron transport layer, followed by depositing an interface modification layer.

[0133] S4. Using a scraper, apply the mixed precursor slurry from step S2 onto the interface modification layer of step S1 to obtain a perovskite wet film with a thickness of 200 μm. Transfer the perovskite wet film to a heating stage for pre-annealing to evaporate some of the solvent. The pre-annealing temperature is 70°C and the pre-annealing time is 60 min, resulting in a wet film to be processed containing a small amount of solvent. Transfer the wet film to be processed containing a small amount of solvent to a pressure press, add a pattern template between the wet film and the perovskite thick film, and perform wet film imprinting. Apply an external force of 700 kPa and imprint for 20 min.

[0134] S5. During wet film imprinting, post-annealing is performed at a temperature of 100℃ for 10 hours to obtain a perovskite thick film with a patterned surface.

[0135] S6. A hole transport layer is prepared by spin-coating 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobisfluorene (spiro-OMeTAD) onto the surface of a perovskite thick film.

[0136] S7. An electrode is prepared on the surface of the hole transport layer in step S6 by dispensing.

[0137] The surface-patterned NIP photodiode prepared above was applied to an X-ray detector, and its imaging capability was tested under X-rays. The scanning object was a copper coin, and the specific imaging results were as follows: Figure 9As shown, the outline of the copper coin is clearly scanned, with obvious contrast between light and dark areas. It is evident that the surface-patterned perovskite thick-film X-ray detector fabricated in this embodiment reduces charge crosstalk between multiple pixels, improves the device's imaging capability, and greatly promotes the application of perovskite materials in the field of X-ray imaging. Specific Implementation Example 5:

[0139] This embodiment provides an X-ray detector with a PIN photodiode structure, such as... Figure 4 As shown, the PIN photodiode includes a conductive substrate 13, a hole transport layer 14, a perovskite thick film 12, an electron transport layer 16, an interface modification layer 15, and an electrode 11, which are stacked and connected sequentially from bottom to top.

[0140] The fabrication method of NIP photodiode is as follows:

[0141] S1. The transparent conductive substrate with indium tin oxide deposited is ultrasonically cleaned with deionized water, acetone and ethanol for 15 min respectively, the transparent conductive substrate is dried with nitrogen gas flow and then treated with ultraviolet ozone for 15 min.

[0142] S2. Weigh the reagents according to the molar ratio to prepare perovskite precursor slurry. Stir the slurry at 60℃ for 10h until the slurry is fully dissolved. Place the slurry in an ultrasonic bath to obtain a fine and dispersed precursor slurry with a concentration of 6mol / L.

[0143] S3. Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) is deposited on a transparent conductive substrate 15 to form a hole transport layer.

[0144] S4. Using a scraper, coat the mixed precursor slurry from step S2 onto the hole transport layer of step S1 to obtain a perovskite wet film with a thickness of 320 μm. Transfer the perovskite wet film to a heating stage for pre-annealing to evaporate some of the solvent. The pre-annealing temperature is 115°C and the pre-annealing time is 40 min, resulting in a wet film to be processed carrying a small amount of solvent. Transfer the wet film to be processed carrying a small amount of solvent to a press, add a pattern template between the wet film and the perovskite thick film, and perform wet film imprinting. Apply an external force of 800 kPa and imprint for 25 min to obtain a perovskite thick film with a patterned surface.

[0145] S5. After the wet film imprinting is completed, post-annealing is performed at a temperature of 120°C for 10 hours to obtain a perovskite thick film with a patterned surface.

[0146] S6. Fullerene (C) is deposited on the surface of a perovskite thick film. 60 Prepare an electron transport layer.

[0147] S7. Prepare an interface modification layer by vapor deposition of 2,9-dimethyl-4,7-diphenyl-o-phenanthroline (BCP, commonly known as copper bath agent) on the surface of the hole transport layer.

[0148] S8. An electrode layer is prepared on the interface modification layer in step S7 by dispensing.

[0149] The surface-patterned NIP photodiode prepared above was applied to an X-ray detector. The device's imaging capability was tested under X-rays with a copper coin as the scanning object. The coin's outline was clearly scanned, and the contrast between light and dark areas was significant. It is evident that the surface-patterned perovskite thick-film X-ray detector prepared in this embodiment reduces charge crosstalk between multiple pixels, improves the device's imaging capability, and greatly promotes the application of perovskite materials in the field of X-ray imaging. Specific Implementation Example 6:

[0151] This embodiment provides an X-ray detector with a PIN photodiode structure, such as... Figure 4 As shown, the PIN photodiode includes a conductive substrate 13, a hole transport layer 14, a perovskite thick film 12, an electron transport layer 16, an interface modification layer 15, and an electrode 11, which are stacked and connected sequentially from bottom to top.

[0152] The fabrication method of NIP photodiode is as follows:

[0153] S1. The transparent conductive substrate with indium tin oxide deposited is ultrasonically cleaned with deionized water, acetone and ethanol for 15 min respectively, the transparent conductive substrate is dried with nitrogen gas flow and then treated with ultraviolet ozone for 15 min.

[0154] S2. Weigh the reagents according to the molar ratio to prepare perovskite precursor slurry. Stir the slurry at 60℃ for 10h until the slurry is fully dissolved. Place the slurry in an ultrasonic bath to obtain a fine and dispersed precursor slurry with a concentration of 6mol / L.

[0155] S3. Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) is deposited on a transparent conductive substrate 15 to form a hole transport layer.

[0156] S4. Using a scraper, coat the mixed precursor slurry from step S2 onto the hole transport layer of step S1 to obtain a perovskite wet film with a thickness of 200 μm. Transfer the perovskite wet film to a heating stage for pre-annealing to evaporate some of the solvent. The pre-annealing temperature is 90°C and the pre-annealing time is 40 min, resulting in a wet film to be processed carrying a small amount of solvent. Transfer the wet film to be processed carrying a small amount of solvent to a press, add a pattern template between the wet film and the perovskite thick film, and perform wet film imprinting. Apply an external force of 800 kPa and imprint for 10 min to obtain a perovskite thick film with a patterned surface.

[0157] S5. During wet film imprinting, post-annealing is performed at a temperature of 100℃ for 10 hours to obtain a perovskite thick film with a patterned surface.

[0158] S6. An electron transport layer is prepared by vapor deposition of fullerene (C60) on the surface of a perovskite thick film.

[0159] S7. Prepare an interface modification layer by evaporating copper bath (BCP) on the surface of the hole transport layer.

[0160] S8. An electrode layer is prepared on the interface modification layer in step S7 by dispensing.

[0161] The surface-patterned PIN photodiode prepared above was applied to an X-ray detector. The device's imaging capability was tested under X-rays with a copper coin as the scanning object. The coin's outline was clearly scanned, and the contrast between light and dark areas was significant. It is evident that the surface-patterned perovskite thick-film X-ray detector prepared in this embodiment reduces charge crosstalk between multiple pixels, improves the device's imaging capability, and greatly promotes the application of perovskite materials in the field of X-ray imaging.

[0162] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of any particular implementation scenario. The above disclosures are merely a few specific implementation scenarios of this application; however, this application is not limited thereto, and any variations conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. A method for preparing a patterned perovskite material layer, characterized in that, The method includes: The perovskite precursor solution is coated onto the substrate to form a perovskite wet film. The perovskite wet film is subjected to a first-stage annealing treatment to obtain the wet film to be treated; The wet film to be processed is subjected to an imprint patterning process, and either a vacuum-assisted process without annealing or a two-stage annealing process to obtain a perovskite material layer with a surface pattern.

2. The method for preparing a patterned perovskite material layer according to claim 1, characterized in that, The process of imprinting patterning onto the wet film to be processed, and any one of vacuum-assisted processing without annealing and two-stage annealing processing, includes: The wet film to be processed is subjected to embossing patterning while simultaneously undergoing vacuum-assisted processing without annealing; or, The wet film to be processed is subjected to embossing patterning while undergoing two-stage annealing; or, After the imprinting patterning process of the wet film to be processed is completed, the wet film to be processed is subjected to a two-stage annealing process.

3. The method for preparing a patterned perovskite material layer according to claim 1, characterized in that, The processing time for the non-annealing vacuum-assisted treatment is 10 min to 4 h. The annealing temperature for the first-stage annealing process is 50℃~130℃, and the annealing time is 10min~4h; The annealing temperature for the two-stage annealing process is 80℃~120℃, and the annealing time is 5h~10h.

4. The method for preparing a patterned perovskite material layer according to claim 1, characterized in that, The imprinting patterning process on the wet film to be processed includes: The wet film to be treated is pressed with pressure using a preset pattern template, wherein the pressing pressure is 100 kPa to 1 MPa and the pressing time is 10 min to 4 h.

5. A perovskite material layer, characterized in that, It is prepared by the method for preparing patterned perovskite material layers as described in any one of claims 1 to 4.

6. A photoconductive structure, characterized in that, It includes a conductive substrate stacked sequentially from bottom to top, a perovskite thick film prepared by the method for preparing a patterned perovskite material layer according to any one of claims 1 to 4, and an electrode.

7. A photodiode, characterized in that, include: NIP type photodiode or PIN type photodiode; The NIP type photodiode includes a conductive substrate, an electron transport layer, a perovskite thick film prepared by the method for preparing patterned perovskite material layers according to any one of claims 1 to 4, a hole transport layer, and an electrode, which are stacked sequentially from bottom to top. The PIN photodiode comprises, from bottom to top, a conductive substrate, a hole transport layer, a perovskite thick film prepared by the method for preparing patterned perovskite material layers according to any one of claims 1 to 4, an electron transport layer, and an electrode. The thickness of the perovskite thick film is 50 μm to 800 μm, the thickness of the hole transport layer is 15 nm to 50 nm, and the thickness of the electrode is 80 nm to 600 nm.

8. A photodiode, characterized in that, include: NIP type photodiode or PIN type photodiode; The NIP type photodiode includes, from bottom to top, a conductive substrate, an electron transport layer, an interface modification layer, a perovskite thick film prepared by the method of preparing patterned perovskite material layer according to any one of claims 1 to 4, a hole transport layer, and an electrode. The PIN photodiode comprises, from bottom to top, a conductive substrate, a hole transport layer, a perovskite thick film prepared by the method for preparing patterned perovskite material layers according to any one of claims 1 to 4, an electron transport layer, an interface modification layer, and an electrode, which are stacked and connected sequentially. The thickness of the perovskite thick film is 50 μm to 800 μm, the thickness of the hole transport layer is 15 nm to 50 nm, the thickness of the electrode is 80 nm to 600 nm, and the thickness of the interface modification layer is 1 nm to 10 nm.

9. A radiation detector, characterized in that, include: The photoconductive structure of claim 6, the photodiode of claim 7, or the photodiode of claim 8.

10. The radiation detector according to claim 9, characterized in that, The hole transport layer in the photodiode is made of at least one material selected from 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobisfluorene, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, nickel oxide, copper thiocyanate, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and polyvinylcarbazole; The electron transport layer in the photodiode is made of at least one material selected from fullerene, fullerene derivatives, tin oxide, titanium dioxide, and zinc oxide. The interface modification layer in the photodiode is made of at least one material selected from lithium fluoride, lithium oxide, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and molybdenum trioxide. The electrodes in the photoconductive structure or the photodiode are made of at least one material selected from gold, silver, copper, and carbon.

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