Perovskite / gallium oxide heterojunction and preparation method of X-ray detector thereof
By fabricating a perovskite/gallium oxide heterojunction structure, the shortcomings of gallium oxide and perovskite materials were overcome, and a high-sensitivity and stable X-ray detector was realized, which is applicable to X-ray detectors with different structures and meets the requirements of low-dose imaging and high stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGGUAN UNIV OF TECH
- Filing Date
- 2026-01-27
- Publication Date
- 2026-04-24
AI Technical Summary
Existing X-ray detector materials, such as gallium oxide, have low X-ray response, and perovskite materials are unstable and have large dark currents, which limits the detection sensitivity and makes it difficult to meet the requirements of low-dose imaging and high stability.
A perovskite/gallium oxide heterojunction structure is employed, and perovskite and gallium oxide thin films are prepared on a substrate using techniques such as magnetron sputtering, spin coating, and electron beam evaporation to form a heterojunction. This heterojunction is then applied to planar MSM, vertical MSM, and vacuum flat-panel X-ray detectors, combining the advantages of both to suppress the instability of perovskite and the low responsivity of gallium oxide.
It achieves X-ray detection with low dose rate, high stability, low dark current and high light-dark current ratio, improves the sensitivity and stability of the detector and expands its application range.
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Figure CN121925008A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of X-ray detector technology, specifically relating to a perovskite / gallium oxide heterojunction and its X-ray detector fabrication method. Background Technology
[0002] X-ray detectors are the core component of X-ray imaging technology. X-ray imaging technology plays an indispensable role in fields such as medical imaging diagnosis, industrial flaw detection, safety inspection, space science, and nuclear technology. With the continuous expansion and deepening of applications, higher demands are being placed on the performance of X-ray detectors. Especially in the medical field, excessive X-ray radiation can damage human organic tissues and increase the risk of cancer. To reduce the harm of X-rays to the human body, low-dose imaging is required in medical diagnosis. Therefore, conducting research on high-sensitivity X-ray detectors is of great significance for promoting the development of X-ray imaging technology and the medical equipment industry.
[0003] Depending on the photoconductive material, X-ray detectors can be classified into indirect or direct X-ray detectors. Indirect X-ray detectors convert X-rays into visible light using a scintillator before detection. Direct X-ray detectors, on the other hand, utilize semiconductor photoconductive materials to directly convert X-ray photons into electrical signals, offering advantages such as high conversion efficiency and high resolution. Therefore, direct X-ray detectors have become the mainstream in research and development. Currently, the commercially available direct X-ray detector is the amorphous selenium detector. However, amorphous selenium has a low atomic number and requires a high electric field (3~10 V / μm) for charge collection, currently limiting its application primarily to low-energy X-ray (less than 50 keV) imaging. Therefore, the search for new alternative materials is necessary.
[0004] Gallium oxide (GaO) is an ultrawide bandgap semiconductor with a bandgap of approximately 4.9 eV. It possesses a high breakdown electric field and stable physicochemical properties, resulting in very low dark current in fabricated X-ray detectors. GaO can also be fabricated over large areas using vacuum deposition techniques, which is beneficial for large-area X-ray imaging. Furthermore, it has shown great potential for detection in extreme environments and at low doses of X-rays. However, GaO's low atomic number, small X-ray absorption coefficient, and short carrier diffusion distance lead to a low X-ray response current and relatively low detection sensitivity.
[0005] Perovskites possess high atomic numbers, high defect tolerance, and long carrier diffusion lengths. They exhibit high X-ray absorption efficiency, effectively converting photons into electrical signals. Furthermore, their low-temperature, large-area fabrication process has led to extensive research and proven them to be ideal materials for achieving high-sensitivity X-ray detection. However, perovskite materials generally suffer from instability, high dark current, and low breakdown voltage.
[0006] In terms of device structure, X-ray detectors are divided into solid-state X-ray detectors and vacuum X-ray detectors. Currently, solid-state X-ray detectors dominate in scientific research and commercialization; however, their sensitivity is limited because they cannot withstand high voltages, and the photoconductor is unlikely to exhibit the avalanche multiplication effect. Cold cathode vacuum flat-panel X-ray detectors, on the other hand, are a novel type of X-ray detector under development. They mainly consist of a cold cathode electron source and a photoconductor, and their main advantages include high sensitivity, the ability to fabricate on a large area, ease of integration, and strong anti-interference capabilities.
[0007] Therefore, the technical problem that this invention needs to solve is how to utilize the stabilizing properties of gallium oxide to suppress the ion migration and performance degradation of perovskite materials, and thus widely apply them to X-ray detectors with different structures. Summary of the Invention
[0008] To overcome the shortcomings of the prior art, this invention provides a perovskite / gallium oxide heterojunction and a method for fabricating its X-ray detector. This invention applies the perovskite / gallium oxide heterojunction to planar MSM-structured solid-state X-ray detectors, vertical MSM-structured solid-state X-ray detectors, and vacuum flat-panel X-ray detectors, achieving low dose rate, high stability, low dark current, and a high photocurrent-to-dark-current ratio in the X-ray detector, highlighting the wide applicability and compatibility of this invention. This invention, through the fabrication of perovskite / gallium oxide heterojunctions, provides a feasible solution for X-ray detectors with low dose rate, high stability, low dark current, and a high photocurrent-to-dark-current ratio.
[0009] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of this invention provides a method for preparing a perovskite / gallium oxide heterojunction, the method comprising the following steps: (1) The substrate was ultrasonically cleaned in sequence using acetone, ethanol and deionized water in three steps. (2) A thin film electrode is deposited on a cleaned substrate using magnetron sputtering; (3) Annealing the thin film electrode using a tube furnace; (4) Drop the prepared perovskite solution onto the annealed thin film electrode, then spin coat it, and add antisolvent during the spin coating process; (5) Baking the perovskite to form a film; (6) Gallium oxide thin films were deposited on the perovskite surface using electron beam evaporation.
[0010] Further, in step (1), the substrate is any one of SiO2 substrate, quartz substrate, glass substrate, ceramic substrate, and stainless steel substrate.
[0011] Further, in step (2), the material of the thin film electrode is any one of ITO, FTO, AZO, GZO, IGZO, or two-dimensional atomic crystal thin film.
[0012] Further, in step (4), the perovskite is any one of FAPbI3, MAPbI3, CsPbI3, CsPbBr3, BaTiO3, SrTiO3 and LaMnO3, and the antisolvent is diethyl ether.
[0013] Furthermore, in step (5), the baking temperature for forming the film is 150 °C.
[0014] A second aspect of the present invention provides a planar MSM structure solid-state X-ray detector comprising the above-described perovskite / gallium oxide heterojunction, wherein the planar MSM structure solid-state X-ray detector is composed of a substrate, a gallium oxide / perovskite heterojunction, and an Au electrode from bottom to top.
[0015] A third aspect of the present invention provides a vertical MSM structure solid-state X-ray detector comprising the above-mentioned perovskite / gallium oxide heterojunction, wherein the vertical MSM structure solid-state X-ray detector is composed of a substrate, a thin film electrode, a perovskite / gallium oxide heterojunction, and an Au electrode from bottom to top.
[0016] Furthermore, the material of the thin film electrode is any one of ITO, FTO, AZO, GZO, IGZO, or two-dimensional atomic crystal thin films.
[0017] A fourth aspect of the present invention provides a vacuum flat panel X-ray detector comprising the above-described perovskite / gallium oxide heterojunction, the vacuum flat panel X-ray detector comprising a vacuum-encapsulated cathode, an anode, and an insulating ceramic sheet between the cathode and the anode, wherein the cathode is composed of a substrate, a thin film electrode, and a ZnO nanowire array from bottom to top, and the anode is composed of a substrate, a thin film electrode, and a gallium oxide / perovskite heterojunction from top to bottom.
[0018] Furthermore, the ZnO nanowire lattice is prepared by photolithography and thermal oxidation growth.
[0019] Compared with the prior art, the beneficial effects of the present invention are: (1) This invention provides a method for preparing a perovskite / gallium oxide heterojunction and has successfully used it to prepare an X-ray detector. It retains the advantages of perovskite's high absorption efficiency and high photoelectric conversion characteristics for X-rays, while suppressing the high dark current and environmental sensitivity of perovskite through the covering effect of gallium oxide on perovskite. It also compensates for the disadvantages of gallium oxide, such as low response to X-rays, low X-ray absorption rate, low detection sensitivity, and low detection limit, through perovskite. It greatly reduces the minimum detection limit, reduces dark current, and increases the photocurrent-to-dark-current ratio, integrating the advantages of both gallium oxide and perovskite, and suppressing their respective disadvantages through complementary advantages.
[0020] (2) The perovskite / gallium oxide heterojunction prepared by this invention has been successfully applied to the anodes of solid-state X-ray detectors and vacuum flat-panel X-ray detectors. This demonstrates the wide applicability and compatibility of the perovskite / gallium oxide heterojunction of this invention, and also provides a reference for subsequent research and development of different types of X-ray detectors. Attached Figure Description
[0021] Figure 1 This is a flowchart of the perovskite / gallium oxide heterojunction preparation method described in this invention.
[0022] Figure 2 This is a schematic diagram of the perovskite / gallium oxide heterojunction structure described in this invention.
[0023] Figure 3 This is a schematic diagram of the planar MSM structure solid-state X-ray detector described in this invention.
[0024] Figure 4 This is a schematic diagram of the vertical MSM structure solid-state X-ray detector described in this invention.
[0025] Figure 5 This is a schematic diagram of the structure of the vacuum flat panel X-ray detector described in this invention.
[0026] Figure 6 The following are the IV characteristic curves of the device described in this embodiment. (a) shows the IV characteristic curves of the perovskite planar MSM type X-ray detector under dark state and X-ray irradiation. (b) shows the IV characteristic curves of the perovskite / gallium oxide heterojunction planar MSM type X-ray detector under dark state and X-ray irradiation.
[0027] Figure 7 The following are the stability test curves of the device described in this embodiment: (a) shows the stability test curve of the perovskite planar MSM type X-ray detector under X-ray irradiation; (b) shows the stability test curve of the perovskite / gallium oxide heterojunction planar MSM type X-ray detector under X-ray irradiation.
[0028] In the attached figures, 1 is a gallium oxide thin film; 2 is a perovskite thin film; 3 is a thin film electrode; 4 is a substrate; 5 is a ZnO nanowire; 6 is an insulating ceramic sheet; 7 is a vacuum environment; 8 is the X-ray irradiation direction; and 9 is an Au electrode. Detailed Implementation
[0029] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0030] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.
[0031] Example 1: Fabrication of a perovskite / gallium oxide heterojunction A method for preparing a perovskite / gallium oxide heterojunction, such as... Figure 1 As shown, its more specific preparation method includes the following steps: (1) Use a glass substrate with a size of 7 cm × 10 cm and a thickness of 3 mm as a substrate, and immerse the glass substrate in acetone, ethanol and deionized water for 20 min in sequence by ultrasonic treatment. (2) An ITO thin film electrode with a thickness of 500 nm was deposited on a cleaned glass substrate using magnetron sputtering technology; (3) The ITO thin film electrode was annealed in a tube furnace at 450 °C to form a dense transparent thin film electrode. (4) 4.45 g of FAPbI3 and 0.14 g of MACl were mixed in 5 mL of a mixed solution of DMF and DMSO as the perovskite precursor solution, wherein the volume ratio of DMF to DMSO was 8:1. The prepared perovskite precursor solution was dropped onto a transparent electrode, and then rapidly spin-coated at 1000 rpm for 10 seconds, followed by spin-coating at 5000 rpm for 20 seconds. Before the spin-coating at 5000 rpm was completed, 5 mL of diethyl ether was quickly dropped onto the glass substrate as a reverse solution. (5) Place the sample obtained in step (4) on a heatable substrate and bake it at 150 °C for 10 min to form a dense polycrystalline FAPbI3 perovskite film, and the thickness of the polycrystalline FAPbI3 perovskite film is 500 nm. (6) Using Ga2O3 particles with a purity of 99.99% and a diameter of 1-3 mm, a Ga2O3 thin film is deposited on the surface of the polycrystalline FAPbI3 perovskite film obtained in step (5) by electron beam evaporation. Before deposition, the deposition chamber needs to be evacuated to 3×10⁻⁶. -3 At a deposition rate of 0.1 nm / s and a deposition time of 500 s, a Ga₂O₃ film with a thickness of 50 nm was obtained. A schematic diagram of the obtained gallium oxide / perovskite heterostructure is shown below. Figure 2 As shown.
[0032] Example 2: Fabrication of a planar MSM structure solid-state X-ray detector A method for fabricating a planar MSM structure solid-state X-ray detector includes the following steps: (1) Use a glass substrate with a size of 7 cm × 10 cm and a thickness of 3 mm as a substrate, and immerse the glass substrate in acetone, ethanol and deionized water for 20 min in sequence by ultrasonic treatment. (2) 4.45 g of FAPbI3 and 0.14 g of MACl were mixed in 5 mL of a mixed solution of DMF and DMSO as the perovskite precursor solution, wherein the volume ratio of DMF to DMSO was 8:1. The prepared perovskite precursor solution was dropped onto a transparent electrode, and then rapidly spin-coated at 1000 rpm for 10 seconds, followed by spin-coating at 5000 rpm for 20 seconds. Before the spin-coating at 5000 rpm was completed, 5 mL of diethyl ether was quickly dropped onto the glass substrate as a reverse solution. (3) Place the sample obtained in step (2) on a heatable substrate and bake it at 150 °C for 10 min to form a dense polycrystalline FAPbI3 perovskite film, and the thickness of the polycrystalline FAPbI3 perovskite film is 500 nm. (4) Using Ga2O3 particles with a purity of 99.99% and a diameter of 1-3 mm, a Ga2O3 thin film is deposited on the surface of the polycrystalline FAPbI3 perovskite film obtained in step (5) by electron beam evaporation. Before deposition, the deposition chamber needs to be evacuated to 3×10⁻⁶. -3 At a deposition rate of 0.1 nm / s and a deposition time of 500 s, a Ga2O3 film with a thickness of 50 nm was obtained. (5) A detector was fabricated by depositing interdigitated Au electrodes with a thickness of 100 nm on the surface of a gallium oxide thin film using magnetron sputtering. The Au electrodes consisted of 10 pairs of patterns, with a spacing of 200 μm between adjacent Au electrodes. A schematic diagram of the resulting planar MSM structure solid-state X-ray detector is shown below. Figure 3 As shown.
[0033] Example 3: Fabrication of a Vertical MSM Structure Solid-State X-ray Detector A method for fabricating a vertical MSM structure solid-state X-ray detector includes the following steps: (1) Use a glass substrate with a size of 7 cm × 10 cm and a thickness of 3 mm as a substrate, and immerse the glass substrate in acetone, ethanol and deionized water for 20 min in sequence by ultrasonic treatment. (2) An ITO thin film electrode with a thickness of 500 nm was deposited on a cleaned glass substrate using magnetron sputtering technology; (3) The ITO thin film electrode was annealed in a tube furnace at 450 °C to form a dense transparent thin film electrode. (4) 4.45 g of FAPbI3 and 0.14 g of MACl were mixed in 5 mL of a mixed solution of DMF and DMSO as the perovskite precursor solution, wherein the volume ratio of DMF to DMSO was 8:1. The prepared perovskite precursor solution was dropped onto a transparent electrode, and then rapidly spin-coated at 1000 rpm for 10 seconds, followed by spin-coating at 5000 rpm for 20 seconds. Before the spin-coating at 5000 rpm was completed, 5 mL of diethyl ether was quickly dropped onto the glass substrate as a reverse solution. (5) Place the sample obtained in step (4) on a heatable substrate and bake it at 150 °C for 10 min to form a dense polycrystalline FAPbI3 perovskite film, and the thickness of the polycrystalline FAPbI3 perovskite film is 500 nm. (6) Using Ga2O3 particles with a purity of 99.99% and a diameter of 1-3 mm, a Ga2O3 thin film is deposited on the surface of the polycrystalline FAPbI3 perovskite film obtained in step (5) by electron beam evaporation. Before deposition, the deposition chamber needs to be evacuated to 3×10⁻⁶. -3 At a deposition rate of 0.1 nm / s and a deposition time of 500 s, a Ga2O3 film with a thickness of 50 nm was obtained. (7) A detector was fabricated by depositing a 100 nm thick Au electrode on the surface of a gallium oxide thin film using magnetron sputtering. The schematic diagram of the resulting vertical MSM structure solid-state X-ray detector is shown below. Figure 4 As shown.
[0034] Example 4: Fabrication of a Vacuum Flat Panel X-ray Detector A schematic diagram of a vacuum flat-panel X-ray detector is shown below. Figure 5As shown, the anode of the device is composed of the gallium oxide / perovskite heterojunction prepared in Example 1 above, while the cathode of the device is composed of a ZnO nanowire array below. The device is isolated from the outside world by an insulating ceramic sheet between the cathode and the anode and is subjected to vacuum treatment. When the X-ray detector is used, the thin film electrode of the cathode is connected to the negative terminal of the external power supply, while the thin film electrode of the anode is connected to the positive terminal of the same power supply.
[0035] The method for preparing the anode is as follows: (1) Use a glass substrate with a size of 7 cm × 10 cm and a thickness of 3 mm as a substrate, and immerse the glass substrate in acetone, ethanol and deionized water for 20 min in sequence by ultrasonic treatment. (2) An ITO thin film electrode with a thickness of 500 nm was deposited on a cleaned glass substrate using magnetron sputtering technology; (3) The ITO thin film electrode was annealed in a tube furnace at 450 °C to form a dense transparent thin film electrode. (4) 4.45 g of FAPbI3 and 0.14 g of MACl were mixed in 5 mL of a mixed solution of DMF and DMSO as the perovskite precursor solution, wherein the volume ratio of DMF to DMSO was 8:1. The prepared perovskite precursor solution was dropped onto a transparent electrode, and then rapidly spin-coated at 1000 rpm for 10 seconds, followed by spin-coating at 5000 rpm for 20 seconds. Before the spin-coating at 5000 rpm was completed, 5 mL of diethyl ether was quickly dropped onto the glass substrate as a reverse solution. (5) Place the sample obtained in step (4) on a heatable substrate and bake it at 150 °C for 10 min to form a dense polycrystalline FAPbI3 perovskite film with a thickness of 500 nm. (6) Using Ga2O3 particles with a purity of 99.99% and a diameter of 1-3 mm, a Ga2O3 thin film is deposited on the surface of the polycrystalline FAPbI3 perovskite film obtained in step (5) by electron beam evaporation. Before deposition, the deposition chamber needs to be evacuated to 3×10⁻⁶. -3 At a deposition rate of 0.1 nm / s and a deposition time of 500 s, a Ga2O3 film with a thickness of 50 nm was obtained, which is the anode.
[0036] The method for preparing the cathode is as follows: (1) Use a glass substrate with a size of 7 cm × 10 cm and a thickness of 3 mm. Immerse the glass substrate in acetone, ethanol and deionized water for 20 min respectively by ultrasonic treatment. (2) An ITO thin film electrode with a thickness of 500 nm was deposited on a cleaned glass substrate using magnetron sputtering technology; (3) The ITO thin film electrode was annealed in a tube furnace at 450 °C to form a dense transparent thin film electrode. (4) A photoresist dot matrix pattern is formed on the ITO thin film electrode using photolithography; (5) Zn film is deposited using electron beam evaporation technology; (6) Use acetone to remove the adhesive and obtain a Zn film lattice pattern sample; (7) ZnO nanowire arrays were obtained by thermal oxidation growth.
[0037] Performance testing: like Figure 6 Figures (a) and (b) show the IV characteristic curves of a monolayer perovskite planar MSM structure X-ray detector and the planar MSM perovskite / gallium oxide heterojunction X-ray detector described in Example 2. This invention compares the IV characteristic curves of the detector under dark conditions and X-ray irradiation conditions. The tube voltage for X-rays is 80 kV, and the tube current is 2.5 mA. At a bias voltage of 50 V, the dark current of the monolayer perovskite planar MSM structure X-ray detector is 10... -7 A, the photocurrent-to-dark-current ratio is 3.2; while the dark current of the planar MSM perovskite / gallium oxide heterojunction X-ray detector is 10. -10 A, the photocurrent-to-dark-current ratio is 291.7. It can be seen that by constructing a gallium oxide / perovskite heterojunction, the dark current of the X-ray detector is reduced by three orders of magnitude, and the photocurrent-to-dark-current ratio is increased by two orders of magnitude.
[0038] like Figure 7 Figures (a) and (b) show the stability test curves of the monolayer perovskite planar MSM structure X-ray detector and the planar MSM gallium oxide / perovskite heterojunction X-ray detector described in Example 2. The test conditions were: a bias voltage of 50 V was applied to the electrodes, and the IT characteristic curves of the detector were tested under X-ray irradiation with a tube voltage of 50 kV and different tube currents. It can be seen that the monolayer perovskite planar MSM structure X-ray detector exhibits instability with a continuously rising photocurrent under continuous X-ray irradiation. In contrast, the planar MSM gallium oxide / perovskite heterojunction X-ray detector shows a more stable photocurrent under continuous X-ray irradiation.
[0039] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.
Claims
1. A method for preparing a perovskite / gallium oxide heterojunction, characterized in that, The preparation method includes the following steps: (1) The substrate was ultrasonically cleaned in sequence using acetone, ethanol and deionized water in three steps. (2) A thin film electrode is deposited on a cleaned substrate using magnetron sputtering; (3) Annealing the thin film electrode using a tube furnace; (4) Drop the prepared perovskite solution onto the annealed thin film electrode, then spin coat it, and add antisolvent during the spin coating process; (5) Baking the perovskite to form a film; (6) Gallium oxide thin films were deposited on the perovskite surface using electron beam evaporation.
2. The method for preparing a perovskite / gallium oxide heterojunction according to claim 1, characterized in that, In step (1), the substrate is any one of SiO2 substrate, quartz substrate, glass substrate, ceramic substrate, and stainless steel substrate.
3. The method for preparing a perovskite / gallium oxide heterojunction according to claim 1, characterized in that, In step (2), the material of the thin film electrode is any one of ITO, FTO, AZO, GZO, IGZO, or two-dimensional atomic crystal thin film.
4. The method for preparing a perovskite / gallium oxide heterojunction according to claim 1, characterized in that, In step (4), the perovskite is any one of FAPbI3, MAPbI3, CsPbI3, CsPbBr3, BaTiO3, SrTiO3 and LaMnO3, and the antisolvent is diethyl ether.
5. A perovskite / gallium oxide heterojunction prepared by the method of any one of claims 1-4.
6. A planar MSM structure solid-state X-ray detector comprising the perovskite / gallium oxide heterojunction of claim 5, characterized in that, The planar MSM structure solid-state X-ray detector consists of a substrate, a perovskite / gallium oxide junction, and an Au electrode, from bottom to top.
7. A vertical MSM structure solid-state X-ray detector comprising the perovskite / gallium oxide heterojunction as described in claim 5, characterized in that, The vertical MSM structure solid-state X-ray detector consists of a substrate, a thin-film electrode, a perovskite / gallium oxide heterojunction, and an Au electrode, from bottom to top.
8. A vertical MSM structure solid-state X-ray detector according to claim 7, characterized in that, The material of the thin film electrode is any one of ITO, FTO, AZO, GZO, IGZO, or two-dimensional atomic crystal thin films.
9. A vacuum flat-panel X-ray detector comprising the gallium oxide / perovskite heterojunction of claim 5, characterized in that, The vacuum flat panel X-ray detector consists of a vacuum-encapsulated cathode, an anode, and an insulating ceramic sheet between the cathode and the anode. The cathode is composed of a substrate, a thin film electrode, and a ZnO nanowire array from bottom to top. The anode is composed of a substrate, a thin film electrode, and a perovskite / gallium oxide heterojunction from top to bottom.
10. A vacuum flat-panel X-ray detector according to claim 9, characterized in that, The ZnO nanowire lattice was prepared by photolithography and thermal oxidation growth.