A high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector, its fabrication method and application

Abstract

This invention relates to a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector, its fabrication method, and its applications. From bottom to top, an n-type Si wafer, an n-type ZnO interlayer, and a lithium-doped p-type NiO thin film are stacked sequentially. A top electrode layer is disposed on the upper surface of the lithium-doped p-type NiO thin film layer, and a bottom electrode layer is disposed on the area of ​​the n-type Si wafer not covered by the n-type ZnO interlayer and the lithium-doped p-type NiO thin film layer. This invention uses magnetron sputtering to sequentially fabricate the n-type ZnO interlayer and the lithium-doped p-type NiO thin film layer on the n-type Si wafer, and uses electron beam evaporation to fabricate the top and bottom electrode layers. Compared with existing technologies, the heterojunction ultraviolet detector fabricated by this invention exhibits both low dark current and low visible light response, and the process is simpler, lower in cost, and can be fabricated on a large area with high feasibility for mass production.

Description

Technical Field

[0001] This invention relates to the field of semiconductor device manufacturing technology, and in particular to a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector, its preparation method and application. Background Technology

[0002] Ultraviolet (UV) radiation consists of electromagnetic waves with wavelengths between 10 nm and 400 nm. Its photon energy is higher than that of visible light, triggering significant photoelectric effects and photochemical reactions. UV detection technology is crucial in modern science and technology, widely used in environmental monitoring, fire early warning, and military reconnaissance. In environmental monitoring, UV detectors provide key data for assessing environmental pollution levels and the impact of solar radiation by accurately measuring atmospheric ozone concentration and surface UV radiation intensity. In fire early warning systems, this technology can sensitively identify specific UV spectra produced by flames, enabling early fire identification and alarm, effectively improving disaster response speed. In the military field, UV detectors, with their high sensitivity and anti-interference capabilities, are used to detect UV signals such as missile exhaust plumes and explosive combustion, providing reliable technical support for battlefield reconnaissance and defense. Currently, with increasingly complex application environments, developing UV detectors with low dark current and low visible light response has become key to driving the development of related technologies. Summary of the Invention

[0003] The purpose of this invention is to provide a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector, its fabrication method, and its application. The ultraviolet detector has low dark current and low visible light response.

[0004] The objective of this invention can be achieved through the following technical solutions: One objective of this invention is to provide a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction pn-type ultraviolet detector, which comprises an n-type Si wafer, an n-type ZnO interlayer, and a lithium-doped p-type NiO thin film layer stacked sequentially from bottom to top. The upper surface of the lithium-doped p-type NiO thin film layer is provided with an upper electrode layer, and the area of ​​the n-type Si wafer not covered by the n-type ZnO interlayer and the lithium-doped p-type NiO thin film layer is provided with a bottom electrode layer.

[0005] Preferably, the n-type Si wafer has a (100) crystal phase.

[0006] Preferably, the resistivity of the n-type Si wafer is 0.1-100 Ω·cm.

[0007] Preferably, the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer are sequentially stacked on the smooth surface of the n-type Si wafer.

[0008] More preferably, the ZnO intermediate layer is configured to form a potential barrier between the n-type Si wafer and the lithium-doped p-type NiO thin film layer, so that the ultraviolet detector exhibits pn junction rectification characteristics.

[0009] Preferably, the thickness of the n-type Si wafer is 0.5~2 mm, the thickness of the n-type ZnO intermediate layer is 10~500 nm, and the thickness of the lithium-doped p-type NiO thin film layer is 10~500 nm.

[0010] More preferably, the thickness of the n-type Si wafer is 0.5 mm.

[0011] More preferably, the thickness of the n-type ZnO intermediate layer is 300 nm.

[0012] More preferably, the thickness of the lithium-doped p-type NiO thin film layer is 200 nm.

[0013] Preferably, the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer have the same area, and the area of ​​the n-type Si wafer is larger than that of the n-type ZnO intermediate layer.

[0014] More preferably, the area of ​​the upper electrode layer and the bottom electrode layer is smaller than the area of ​​the n-type ZnO intermediate layer.

[0015] Preferably, the upper electrode layer is a nickel-chromium composite electrode layer, which includes a Ni thin film layer and a Cr thin film layer stacked sequentially, wherein the Ni thin film layer is in contact with the lithium-doped p-type NiO thin film layer.

[0016] Preferably, the bottom electrode layer is a titanium-chromium composite electrode layer, which includes a Ti thin film layer and a Cr thin film layer stacked sequentially, and the Ti thin film layer is in contact with the n-type Si wafer.

[0017] Preferably, in the upper electrode layer, the thickness of the Ni thin film layer is 5~100 nm, and the thickness of the Cr thin film layer is 5~100 nm.

[0018] More preferably, in the upper electrode layer, the thickness of the Ni thin film layer is 50 nm, and the thickness of the Cr thin film layer is 50 nm.

[0019] More preferably, in the upper electrode layer, the Ni thin film layer and the Cr thin film layer have the same area.

[0020] Preferably, in the bottom electrode layer, the thickness of the Ti thin film layer is 5~100 nm, and the thickness of the Cr thin film layer is 5~100 nm.

[0021] More preferably, in the bottom electrode layer, the thickness of the Ti thin film layer is 50 nm, and the thickness of the Cr thin film layer is 50 nm.

[0022] More preferably, in the bottom electrode layer, the Ti thin film layer and the Cr thin film layer have the same area.

[0023] More preferably, the upper electrode layer comprises a plurality of identical electrodes.

[0024] More preferably, the upper electrode layer comprises two identical nickel-chromium composite electrodes.

[0025] More preferably, the bottom electrode layer comprises a plurality of identical electrodes.

[0026] More preferably, the bottom electrode layer comprises two identical titanium-chromium composite electrodes.

[0027] Preferably, the lithium doping amount in the lithium-doped p-type NiO thin film layer is 0.5~5wt%.

[0028] More preferably, the lithium doping amount in the lithium-doped p-type NiO thin film layer is 2wt%.

[0029] More preferably, the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer are prepared by photomask and magnetron sputtering, and the upper electrode layer and the bottom electrode layer are prepared by photomask and electron beam evaporation.

[0030] The second objective of this invention is to provide a method for fabricating the high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector, comprising the following steps: S1. Pretreatment of n-type Si wafers; S2. Sputter an n-type ZnO intermediate layer onto the pretreated n-type Si wafer using a mask and magnetron sputtering. S3. A lithium-doped p-type NiO thin film layer is sputtered on the n-type ZnO intermediate layer using a mask and magnetron sputtering. S4. An upper electrode layer was prepared on a lithium-doped p-type NiO thin film using a mask and electron beam evaporation. S5. In the area of ​​the pretreated n-type Si wafer not covered by the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer, a bottom electrode layer is prepared by means of a mask and electron beam evaporation to prepare the high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector.

[0031] Preferably, in step S1, the pretreatment refers to ultrasonically treating the n-type Si wafer in acetone, ethanol, and deionized water respectively, and then drying it with high-purity nitrogen gas to obtain a clean and dry substrate.

[0032] More preferably, in step S1, the pretreatment refers to ultrasonic cleaning with acetone, anhydrous ethanol and deionized water for 5-30 min respectively, followed by drying with high-purity nitrogen (99.99% purity) to obtain a clean and dry substrate.

[0033] Preferably, in step S2, the opening of the mask is rectangular, with dimensions of 12.5 mm * 9.5 mm to 15.5 mm * 12.5 mm, and more preferably 15.5 mm * 12.5 mm.

[0034] Preferably, in step S2, the magnetron sputtering uses a high-purity ZnO ceramic target with a purity higher than 99.99%, and the base vacuum of the magnetron sputtering is 2*10⁻⁶. -8 ~2*10 -6 The magnetron sputtering is performed under an argon atmosphere with a gas flow rate in the range of 10~100 sccm, a sputtering pressure of 0.3~1 Pa, and a sputtering power of 10~300 W.

[0035] More preferably, in step S2, the gas flow rate of the argon atmosphere is 20 sccm.

[0036] Preferably, in step S2, the sputtering process involves pre-sputtering for 1 to 30 minutes, then opening the baffle to begin formal sputtering, with the formal sputtering time being 30 to 120 minutes. After sputtering is completed, the n-type ZnO intermediate layer is obtained.

[0037] More preferably, in step S2, during magnetron sputtering, the rotation speed of the tray used to place the sample is ≤5 rad / min. After 15 min of pre-sputtering, the baffle is opened to start the formal sputtering. After the sputtering is completed, an n-type ZnO intermediate layer with a thickness of 300 nm is obtained.

[0038] Preferably, in step S3, the opening of the mask is rectangular, with dimensions of 12.5 mm * 9.5 mm to 15.5 mm * 12.5 mm, and more preferably 15.5 mm * 12.5 mm.

[0039] Preferably, in step S3, the magnetron sputtering uses a NiO ceramic target with a lithium doping content of 0.5~5wt%, and the base vacuum degree of the magnetron sputtering is 2*10 -6 ~2*10 -4 The magnetron sputtering is performed under an argon atmosphere with a gas flow rate in the range of 10~100 sccm, a sputtering pressure of 0.3~1 Pa, and a sputtering power of 10~300W.

[0040] More preferably, in step S3, the magnetron sputtering uses a NiO ceramic target with a lithium doping content of 2wt%.

[0041] More preferably, in step S3, the gas flow rate of the argon atmosphere is 20 sccm.

[0042] Preferably, in step S3, the sputtering process involves pre-sputtering for 1 to 30 minutes, then opening the baffle to begin formal sputtering, with a formal sputtering time of 30 to 120 minutes. After sputtering is completed, the lithium-doped p-type NiO thin film layer is obtained.

[0043] More preferably, in step S3, during magnetron sputtering, the rotation speed of the tray used to place the sample is ≤5 rad / min. After 15 min of pre-sputtering, the baffle is opened to start the formal sputtering. After the sputtering is completed, a lithium-doped p-type NiO thin film layer with a thickness of 200 nm is obtained.

[0044] Preferably, step S4 specifically includes: firstly, preparing a Ni thin film layer on a lithium-doped p-type NiO thin film layer using a mask and electron beam evaporation, and then preparing a Cr thin film layer on the Ni thin film layer using the same mask-assisted electron beam evaporation.

[0045] Preferably, in step S4, the opening of the mask is square, with a size of 2 mm*2 mm to 6 mm*6 mm, and more preferably 4 mm*4 mm.

[0046] More preferably, in step S4, the mask has multiple openings, and even more preferably, it has two square openings.

[0047] Preferably, in step S4, when preparing the Ni thin film layer, a high-purity nickel target with a purity higher than 99.99% is used, the background vacuum degree of the electron beam evaporation is 2*10E-6~2*10E-4Pa, the electron gun beam current is adjusted to 40~80mA and then the baffle is opened to start evaporation. After evaporation is completed, the Ni thin film layer is obtained.

[0048] Preferably, in step S4, when preparing the Cr thin film layer, a high-purity chromium target with a purity higher than 99.99% is used, and the background vacuum degree of the electron beam evaporation is 2*10. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 10~20mA, the baffle is opened to start evaporation. After evaporation is completed, the upper electrode layer is obtained.

[0049] More preferably, in step S4, during electron beam evaporation, the rotation speed of the tray used to place the sample is ≤5 rad / min, and after evaporation is completed, a Ni thin film layer with a thickness of 50 nm and a Cr thin film layer with a thickness of 50 nm are obtained.

[0050] Preferably, step S5 specifically includes: firstly, preparing a Ti thin film layer on the n-type Si wafer in the region not covered by the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer using a mask and electron beam evaporation method; then preparing a Cr thin film layer on the Ti thin film layer using the same mask-assisted electron beam evaporation method.

[0051] Preferably, in step S5, the opening of the mask is square, with a size of 2 mm*2 mm to 6 mm*6 mm, and more preferably 4 mm*4 mm.

[0052] More preferably, in step S5, the mask has multiple openings, and even more preferably, it has two square openings.

[0053] Preferably, in step S5, when preparing the Ti thin film layer, a high-purity titanium target with a purity higher than 99.99% is used, and the background vacuum degree of the electron beam evaporation is 2*10. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 20~60mA, the baffle is opened to start evaporation. After evaporation is complete, the Ti thin film layer is obtained.

[0054] Preferably, in step S5, when preparing the Cr thin film layer, a high-purity chromium target with a purity higher than 99.99% is used, and the background vacuum degree of the electron beam evaporation is 2*10⁻⁶. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 10~20mA, the baffle is opened to start evaporation. After evaporation is complete, the bottom electrode layer is obtained.

[0055] More preferably, in step S5, during electron beam evaporation, the rotation speed of the tray used to place the sample is ≤5 rad / min, and after evaporation is completed, a Ti thin film layer with a thickness of 50 nm and a Cr thin film layer with a thickness of 50 nm are obtained.

[0056] Preferably, the fabrication method of the high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector includes the following steps: (1) Substrate treatment: An n-type Si wafer was selected; the substrate was sequentially ultrasonicated in acetone, ethanol, and deionized water, and then dried with high-purity nitrogen to obtain a clean and dry substrate. The cleaned substrate was then placed into the magnetron sputtering cavity. (2) Preparation of ZnO intermediate layer: The substrate processed in step (1) is sent into the magnetron sputtering cavity. A high-purity ZnO ceramic target with a purity of 99.99% is selected. A stainless steel mask with a rectangular opening (15.5 mm * 12.5 mm) is selected to cover the smooth surface of the substrate and then placed on the sample stage. After the sputtering cavity is evacuated, argon gas with a flow rate of 10~100 sccm is introduced. The sputtering pressure and sputtering power are set to 0.3~1 Pa and 10~300 W, respectively. After pre-sputtering for 1~30 min, the baffle is opened to start the formal sputtering. After the sputtering is completed, a ZnO intermediate layer with a thickness of 10~500 nm is obtained. (3) Preparation of lithium-doped NiO thin film: The target material is a NiO ceramic target with a lithium doping amount of 2 wt%; a stainless steel mask plate with a rectangular opening (15.5 mm * 12.5 mm) is selected to cover the ZnO thin film surface, and the ZnO thin film sample obtained in step (2) is placed on the sample stage; after the sputtering chamber is evacuated, argon gas with a flow rate of 10~100 sccm is introduced; the sputtering pressure and sputtering power are set to 0.3~1 Pa and 10~300 W respectively, and the baffle is opened to start the formal sputtering after 1~30 min of pre-sputtering. After the sputtering is completed, a lithium-doped nickel oxide thin film layer with a thickness of 10~500 nm is obtained. (4) Fabrication of the upper electrode layer: The nickel oxide thin film sample obtained in step (3) is sent into the electron beam cavity. A nickel target is selected as the target material. A stainless steel mask plate with two square openings (4 mm * 4 mm) is selected to cover the nickel oxide thin film surface and then placed on the sample stage. After the cavity is evacuated, the electron gun beam current is adjusted, the baffle is opened to start evaporation, and after evaporation is completed, a nickel thin film with a thickness of 5~100 nm is obtained. A chromium target material is selected again, the electron gun beam current is adjusted, the baffle is opened to start evaporation, and after evaporation is completed, a chromium thin film with a thickness of 5~100 nm is obtained.

[0057] (5) Fabrication of the bottom electrode layer: The sample obtained in step (4) is sent into the electron beam cavity. A titanium target is selected as the target material. A stainless steel mask with two square openings (4 mm * 4 mm) is selected to cover the smooth surface of the Si substrate and then placed on the sample stage. After the cavity is evacuated, a titanium film with a thickness of 5~100 nm is evaporated. A chromium target is selected and a chromium film with a thickness of 5~100 nm is evaporated to obtain the high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector.

[0058] The third objective of this invention is to provide an application of the high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector in the field of ultraviolet detection.

[0059] Improving the performance and optimizing the structure of ultraviolet (UV) detectors has always been a key research focus in the optoelectronic field. Among these, heterojunction pn structures, due to their ability to optimize photoelectric response characteristics through bandgap modulation, have become an important research direction for UV detectors. NiO, as a natural p-type semiconductor material, possesses a wide bandgap of approximately 3.6 eV, exhibiting not only high sensitivity to ultraviolet light but also extremely low response to visible light. Furthermore, its absorption coefficient at 380 nm exceeds 10. 5 cm -1 Its transmittance in the visible light region can reach over 80%, coupled with excellent hole transport characteristics (hole mobility 0.1~10cm). 2 With an exciton binding energy of 110 meV / s, it can ensure the efficient generation and separation of photogenerated carriers, making it an ideal choice for ultraviolet detection materials.

[0060] Due to its low cost, mature fabrication process, and excellent electrical properties, Si materials are widely used in the fabrication of heterojunction pn devices. Therefore, NiO / Si heterojunction structures theoretically possess significant advantages in terms of sensitivity, responsivity, response speed, flexibility, and cost-effectiveness in ultraviolet detectors. However, traditional NiO / Si heterojunction ultraviolet detectors generally suffer from technical defects such as excessively high dark current and significant interference in visible light response, severely limiting their practical application performance.

[0061] To address the aforementioned technical problems, this invention, through systematic analysis of material properties and band structure, introduces a ZnO intermediate layer to construct a Li-doped NiO / ZnO / Si (Li:NiO / ZnO / Si) heterojunction structure. ZnO, as a wide-bandgap n-type semiconductor, has its conduction band bottom and valence band top energy levels located between Si and NiO. This unique band arrangement effectively blocks hole injection from the p-type NiO layer to the n-type Si layer, while simultaneously creating a potential well effect for electron transport. This significantly reduces device dark current and suppresses visible light response interference, thereby optimizing detection performance.

[0062] Furthermore, to improve the electrical performance of NiO materials, this invention introduces Li doping into NiO: by replacing Ni with lithium ions to form acceptor levels, the hole concentration and conductivity of the material can be effectively increased, the carrier injection efficiency and collection capability can be enhanced, and the thin film crystal quality can be optimized, the grain boundary scattering effect can be reduced, thereby improving the photoelectric response performance and long-term working stability of the device.

[0063] In selecting the thin film preparation process, the advantages and disadvantages of various preparation methods are comprehensively considered: the preparation methods of ZnO thin films and NiO thin films mainly include magnetron sputtering, solution-gel method, thermal evaporation method, hydrothermal method (ZnO) and molecular beam epitaxy, pulsed laser deposition (NiO), etc. Among them, due to its simple process, high film density and strong adhesion to the substrate, the core preparation process of this invention is magnetron sputtering to prepare ZnO thin films and Li-doped NiO (Li:NiO) thin films; the electrode preparation adopts electron beam evaporation method, and the good ohmic contact between the electrode and the functional layer is ensured by precisely controlling the process parameters.

[0064] In summary, this invention employs magnetron sputtering to sequentially prepare a ZnO intermediate layer and a Li:NiO thin film layer on an n-type Si wafer. By optimizing process parameters such as sputtering power, the quality of the thin film is ensured. Electrodes are then prepared using electron beam evaporation, ultimately achieving the fabrication of a high-performance lithium-doped nickel oxide / zinc oxide / silicon (Li:NiO / ZnO / Si) heterojunction ultraviolet detector.

[0065] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention provides a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector and its preparation method and application. The detector adopts a stacked structure of n-type Si wafer, n-type ZnO intermediate layer and lithium-doped p-type NiO thin film layer. With the reasonable arrangement of the top electrode layer and bottom electrode layer, the device finally prepared has the core advantages of low dark current and low visible light response, which effectively solves the performance shortcomings of traditional ultraviolet detectors and improves the reliability of practical applications.

[0066] (2) The present invention uses a lithium-doped p-type NiO thin film layer. By introducing a large number of holes through lithium ion doping, the conductivity of NiO material is significantly improved, effectively optimizing the conductivity and carrier transport efficiency of the device, laying the material foundation for high-sensitivity detection of the device.

[0067] (3) By introducing an n-type ZnO intermediate layer as an intermediate barrier layer, the present invention can effectively block hole injection and suppress electron recombination by taking advantage of its unique band matching relationship with NiO and Si, thereby significantly reducing the interference of device dark current and visible light response, and greatly improving the detection efficiency of ultraviolet detection.

[0068] (4) The Li:NiO / ZnO / Si heterojunction structure constructed in this invention, relying on the synergistic effect of each layer of materials, not only significantly reduces dark current, but also simultaneously improves the response speed and detectivity of the device. Its overall photoelectric performance is superior to that of traditional NiO / Si heterojunction ultraviolet detectors.

[0069] (5) The present invention uses magnetron sputtering and selects an appropriate sputtering power to prepare zinc oxide and nickel oxide thin films, and uses electron beam evaporation to prepare nickel-chromium top electrode and titanium-chromium substrate electrode. It is simpler to operate, lower in cost, can be prepared on a large area, and has high feasibility for batch growth than other growth processes. Attached Figure Description

[0070] Figure 1 This is a schematic diagram of the fabrication process and device structure of the high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector of the present invention. Detailed Implementation

[0071] This embodiment is implemented based on the technical solution of the present invention, and provides detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiment.

[0072] Unless otherwise specified, the reagents, methods, instruments, and equipment used in this invention are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0073] This invention provides a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector, such as... Figure 1 As shown, an n-type Si wafer, an n-type ZnO intermediate layer, and a lithium-doped p-type NiO thin film layer are stacked sequentially from bottom to top. The upper surface of the lithium-doped p-type NiO thin film layer is provided with an upper electrode layer, and the area on the n-type Si wafer not covered by the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer is provided with a bottom electrode layer.

[0074] In this heterogeneous pn junction ultraviolet detector, the thickness of the n-type Si wafer is 0.5~2 mm, the thickness of the n-type ZnO interlayer is 10~500 nm, and the thickness of the lithium-doped p-type NiO thin film layer is 10~500 nm. The n-type ZnO interlayer and the lithium-doped p-type NiO thin film layer have the same area, and the area of ​​the n-type Si wafer is larger than that of the n-type ZnO interlayer.

[0075] In this heterojunction pn-type ultraviolet detector, the upper electrode layer is a nickel-chromium composite electrode layer, which includes sequentially stacked Ni and Cr thin film layers, with the Ni thin film layer in contact with a lithium-doped p-type NiO thin film layer; the bottom electrode layer is a titanium-chromium composite electrode layer, which includes sequentially stacked Ti and Cr thin film layers, with the Ti thin film layer in contact with an n-type Si wafer. Specifically, in the upper electrode layer, the Ni and Cr thin film layers have thicknesses of 5–100 nm and are of the same area; similarly, in the bottom electrode layer, the Ti and Cr thin film layers have thicknesses of 5–100 nm and are of the same area.

[0076] In this heterojunction ultraviolet detector, the upper electrode layer includes two identical nickel-chromium composite electrodes, and the bottom electrode layer includes two identical titanium-chromium composite electrodes.

[0077] In this heterojunction-type ultraviolet detector, the lithium doping amount in the lithium-doped p-type NiO thin film layer is 0.5~5wt%.

[0078] The fabrication method of the above-mentioned high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector includes the following steps: S1. Pretreatment of n-type Si wafers; S2. Sputter an n-type ZnO intermediate layer onto the pretreated n-type Si wafer using a mask and magnetron sputtering. S3. A lithium-doped p-type NiO thin film layer is sputtered on the n-type ZnO intermediate layer using a mask and magnetron sputtering. S4. An upper electrode layer was prepared on a lithium-doped p-type NiO thin film using a mask and electron beam evaporation. S5. In the area of ​​the pretreated n-type Si wafer not covered by the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer, a bottom electrode layer is prepared by photomask and electron beam evaporation to obtain a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector.

[0079] Further explanation of each of the above steps: In step S1, the pretreatment refers to ultrasonically cleaning the n-type Si wafer in acetone, ethanol and deionized water for 5-30 min respectively, and then drying it with high-purity nitrogen gas (99.99% purity) to obtain a clean and dry substrate.

[0080] In step S2, the opening of the mask is rectangular, with dimensions of 12.5 mm * 9.5 mm to 15.5 mm * 12.5 mm. The magnetron sputtering uses a high-purity ZnO ceramic target with a purity exceeding 99.99%, and the base vacuum level for magnetron sputtering is 2 * 10⁻⁶. -8 ~2*10 -6 The magnetron sputtering was performed under an argon atmosphere with a gas flow rate of 10–100 sccm, a sputtering pressure of 0.3–1 Pa, and a sputtering power of 10–300 W. The sputtering process involved pre-sputtering for 1–30 min, followed by opening the baffle to begin the formal sputtering, which lasted for 30–120 min. After sputtering, an n-type ZnO intermediate layer was obtained.

[0081] In step S3, the opening of the mask is rectangular, with dimensions of 12.5 mm * 9.5 mm to 15.5 mm * 12.5 mm. Magnetron sputtering uses a NiO ceramic target with a lithium doping content of 0.5 to 5 wt%, and the base vacuum level for magnetron sputtering is 2 * 10⁻⁶. -6 ~2*10 -4 Magnetron sputtering was performed under an argon atmosphere with a gas flow rate of 10–100 sccm, a sputtering pressure of 0.3–1 Pa, and a sputtering power of 10–300 W. The sputtering process involved pre-sputtering for 1–30 min, followed by opening the baffle to begin formal sputtering, which lasted for 30–120 min. After sputtering, a lithium-doped p-type NiO thin film was obtained.

[0082] Step S4 specifically includes: firstly, a Ni thin film layer is prepared on a lithium-doped p-type NiO thin film layer using a mask and electron beam evaporation, and then a Cr thin film layer is prepared on the Ni thin film layer using the same mask-assisted electron beam evaporation. The mask has (2) square openings with dimensions of 2 mm*2 mm to 6 mm*6 mm. When preparing the Ni thin film, a high-purity nickel target with a purity higher than 99.99% was used, and the background vacuum level for electron beam evaporation was 2*10⁻⁶. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 40~80mA, the baffle is opened to start evaporation. After evaporation is complete, a Ni thin film layer is obtained. When preparing the Cr thin film, a high-purity chromium target with a purity higher than 99.99% was used, and the background vacuum level for electron beam evaporation was 2*10⁻⁶. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 10~20mA, the baffle is opened to start evaporation, and the upper electrode layer is obtained after evaporation is completed.

[0083] Step S5 specifically includes: firstly, preparing a Ti thin film layer on the n-type Si wafer in the region not covered by the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer using a mask and electron beam evaporation method; then preparing a Cr thin film layer on the Ti thin film layer using the same mask-assisted electron beam evaporation method. The mask has (2) square openings with dimensions of 2 mm*2 mm to 6 mm*6 mm. When preparing the Ti thin film, a high-purity titanium target with a purity higher than 99.99% was used, and the background vacuum level for electron beam evaporation was 2*10⁻⁶. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 20~60mA, the baffle is opened to start evaporation. After evaporation is complete, a Ti thin film layer is obtained. When preparing the Cr thin film, a high-purity chromium target with a purity higher than 99.99% was used, and the background vacuum level for electron beam evaporation was 2*10⁻⁶. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 10~20mA, the baffle is opened to start evaporation, and the bottom electrode layer is obtained after evaporation is completed.

[0084] In the following embodiments, radio frequency magnetron sputtering was used to prepare Li:NiO / ZnO / Si heterojunction thin films on n-type Si wafers, and electron beam evaporation was used to prepare the electrode layers. The thin film preparation methods of this invention are simple to operate, low in cost, and highly effective. The ultraviolet detector with high response speed and high detectivity obtained by this invention can be better applied in ultraviolet detection and other fields. The invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0085] Example 1: In this embodiment, a high-performance Li:NiO / ZnO / Si heterojunction ultraviolet detector fabricated on an n-type Si wafer includes the following steps: (1) Substrate treatment: An n-type Si wafer was selected and cut to a size of 19.5 mm × 19.5 mm with a thickness of 0.5 mm. The substrate was then ultrasonically treated in acetone, ethanol, and deionized water for 5 min each, and dried with high-purity nitrogen gas to obtain a clean and dry substrate. The cleaned substrate was then placed into the magnetron sputtering cavity. (2) Preparation of ZnO intermediate layer: The substrate processed in step (1) was sent into the magnetron sputtering cavity. A high-purity ZnO ceramic target with a purity of 99.99% was selected. A stainless steel mask with a rectangular opening (15.5 mm * 12.5 mm) was selected to cover the smooth surface of the substrate and then placed on the sample stage. After the sputtering cavity was evacuated, argon gas with a flow rate of 20 sccm was introduced. The sputtering pressure and sputtering power were set to 0.6 Pa and 125 W, respectively. After pre-sputtering for 15 min, the baffle was opened to start the formal sputtering. After the sputtering was completed, a ZnO intermediate layer with a thickness of 300 nm was obtained. (3) Preparation of lithium-doped NiO thin film: The target material selected is NiO ceramic target with lithium doping of 2 wt%; a stainless steel mask plate with a rectangular opening (15.5 mm * 12.5 mm) is selected to cover the ZnO thin film surface, and the ZnO thin film sample obtained in step (2) is placed on the sample stage; after the sputtering chamber is evacuated, argon gas with a flow rate of 20 sccm is introduced; the sputtering pressure and sputtering power are set to 0.6 Pa and 60 W respectively, and the baffle is opened to start the formal sputtering after 15 min of pre-sputtering. After the sputtering is completed, a lithium-doped nickel oxide thin film layer with a thickness of 200 nm is obtained. (4) Fabrication of the upper electrode layer: The nickel oxide thin film sample obtained in step (3) is sent into the electron beam cavity. A nickel target is selected as the target material. A stainless steel mask plate with two square openings (4 mm * 4 mm) is selected to cover the nickel oxide thin film surface and then placed on the sample stage. After the cavity is evacuated, the electron gun beam current is adjusted to 60 mA and the baffle is opened to start evaporation. After evaporation is completed, a nickel thin film with a thickness of 50 nm is obtained. A chromium target is selected again, the electron gun beam current is adjusted to 15 mA and the baffle is opened to start evaporation. After evaporation is completed, a chromium thin film with a thickness of 50 nm is obtained.

[0086] (5) Fabrication of the bottom electrode layer: The sample obtained in step (4) is sent into the electron beam cavity. A titanium target is selected as the target material. A stainless steel mask with two square openings (4 mm * 4 mm) is selected to cover the smooth surface of the substrate and then placed on the sample stage. After the cavity is evacuated, the electron gun beam current is adjusted to 40 mA and the baffle is opened to start evaporation. After evaporation is completed, a titanium film with a thickness of 50 nm is obtained. A chromium target is selected again, the electron gun beam current is adjusted to 15 mA and the baffle is opened to start evaporation. After evaporation is completed, a chromium film with a thickness of 50 nm is obtained, which is the high-performance Li:NiO / ZnO / Si heterojunction ultraviolet detector.

[0087] Example 2: This embodiment is basically the same as Embodiment 1, except that a sputtering power of 150 W is used when preparing the ZnO intermediate layer in this embodiment.

[0088] In this embodiment, a high-performance Li:NiO / ZnO / Si heterojunction ultraviolet detector fabricated on an n-type Si wafer includes the following steps: (1) Substrate treatment: An n-type Si wafer was selected and cut to a size of 19.5 mm × 19.5 mm with a thickness of 0.5 mm. The substrate was then ultrasonically treated in acetone, ethanol, and deionized water for 5 min each, and dried with high-purity nitrogen gas to obtain a clean and dry substrate. The cleaned substrate was then placed into the magnetron sputtering cavity. (2) Preparation of ZnO intermediate layer: The substrate processed in step (1) was sent into the magnetron sputtering cavity. A high-purity ZnO ceramic target with a purity of 99.99% was selected. A stainless steel mask with a rectangular opening (15.5 mm * 12.5 mm) was selected to cover the smooth surface of the substrate and then placed on the sample stage. After the sputtering cavity was evacuated, argon gas with a flow rate of 20 sccm was introduced. The sputtering pressure and sputtering power were set to 0.6 Pa and 150 W, respectively. After pre-sputtering for 15 min, the baffle was opened to start the formal sputtering. After the sputtering was completed, a ZnO intermediate layer with a thickness of 300 nm was obtained. (3) Preparation of lithium-doped NiO thin film: NiO ceramic target with lithium doping of 2 wt% was selected as the target material; a stainless steel mask plate with a rectangular opening (15.5 mm * 12.5 mm) was selected to cover the ZnO thin film surface, and the ZnO thin film sample obtained in step (2) was placed on the sample stage; after the sputtering chamber was evacuated, argon gas with a flow rate of 20 sccm was introduced; the sputtering pressure and sputtering power were set to 0.6 Pa and 60 W respectively, and the baffle was opened to start the formal sputtering after 15 min of pre-sputtering. After the sputtering was completed, a nickel oxide thin film layer with a thickness of 200 nm was obtained. (4) Fabrication of the upper electrode layer: The nickel oxide thin film sample obtained in step (3) is sent into the electron beam cavity. A nickel target is selected as the target material. A stainless steel mask plate with two square openings (4 mm * 4 mm) is selected to cover the nickel oxide thin film surface and then placed on the sample stage. After the cavity is evacuated, the electron gun beam current is adjusted to 60 mA and the baffle is opened to start evaporation. After evaporation is completed, a nickel thin film with a thickness of 50 nm is obtained. A chromium target is selected again, the electron gun beam current is adjusted to 15 mA and the baffle is opened to start evaporation. After evaporation is completed, a chromium thin film with a thickness of 50 nm is obtained.

[0089] (5) Fabrication of the bottom electrode layer: The sample obtained in step (4) is sent into the electron beam cavity. A titanium target is selected as the target material. A stainless steel mask with two square openings (4 mm * 4 mm) is selected to cover the smooth surface of the substrate and then placed on the sample stage. After the cavity is evacuated, the electron gun beam current is adjusted to 40 mA and the baffle is opened to start evaporation. After evaporation is completed, a titanium film with a thickness of 50 nm is obtained. A chromium target is selected again, the electron gun beam current is adjusted to 15 mA and the baffle is opened to start evaporation. After evaporation is completed, a chromium film with a thickness of 50 nm is obtained, which is the high-performance Li:NiO / ZnO / Si heterojunction ultraviolet detector.

[0090] Example 3: This embodiment is basically the same as Embodiment 1, except that a sputtering power of 175 W is used when preparing the ZnO intermediate layer in this embodiment.

[0091] In this embodiment, a high-performance Li:NiO / ZnO / Si heterojunction ultraviolet detector fabricated on an n-type Si wafer includes the following steps: (1) Substrate treatment: An n-type Si wafer was selected and cut to a size of 19.5 mm × 19.5 mm with a thickness of 0.5 mm. The substrate was then ultrasonically treated in acetone, ethanol, and deionized water for 5 min each, and dried with high-purity nitrogen gas to obtain a clean and dry substrate. The cleaned substrate was then placed into the magnetron sputtering cavity. (2) Preparation of ZnO intermediate layer: The substrate processed in step (1) was sent into the magnetron sputtering cavity. A high-purity ZnO ceramic target with a purity of 99.99% was selected. A stainless steel mask with a rectangular opening (15.5 mm * 12.5 mm) was selected to cover the smooth surface of the substrate and then placed on the sample stage. After the sputtering cavity was evacuated, argon gas with a flow rate of 20 sccm was introduced. The sputtering pressure and sputtering power were set to 0.6 Pa and 175 W, respectively. After pre-sputtering for 15 min, the baffle was opened to start the formal sputtering. After the sputtering was completed, a ZnO intermediate layer with a thickness of 300 nm was obtained. (3) Preparation of lithium-doped NiO thin film: NiO ceramic target with lithium doping of 2 wt% was selected as the target material; a stainless steel mask plate with a rectangular opening (15.5 mm * 12.5 mm) was selected to cover the ZnO thin film surface, and the ZnO thin film sample obtained in step (2) was placed on the sample stage; after the sputtering chamber was evacuated, argon gas with a flow rate of 20 sccm was introduced; the sputtering pressure and sputtering power were set to 0.6 Pa and 60 W respectively, and the baffle was opened to start the formal sputtering after 15 min of pre-sputtering. After the sputtering was completed, a nickel oxide thin film layer with a thickness of 200 nm was obtained. (4) Fabrication of the upper electrode layer: The nickel oxide thin film sample obtained in step (3) is sent into the electron beam cavity. A nickel target is selected as the target material. A stainless steel mask plate with two square openings (4 mm * 4 mm) is selected to cover the nickel oxide thin film surface and then placed on the sample stage. After the cavity is evacuated, the electron gun beam current is adjusted to 60 mA and the baffle is opened to start evaporation. After evaporation is completed, a nickel thin film with a thickness of 50 nm is obtained. A chromium target is selected again, the electron gun beam current is adjusted to 15 mA and the baffle is opened to start evaporation. After evaporation is completed, a chromium thin film with a thickness of 50 nm is obtained.

[0092] (5) Fabrication of the bottom electrode layer: The sample obtained in step (4) is sent into the electron beam cavity. A titanium target is selected as the target material. A stainless steel mask with two square openings (4 mm * 4 mm) is selected to cover the smooth surface of the substrate and then placed on the sample stage. After the cavity is evacuated, the electron gun beam current is adjusted to 40 mA and the baffle is opened to start evaporation. After evaporation is completed, a titanium film with a thickness of 50 nm is obtained. A chromium target is selected again, the electron gun beam current is adjusted to 15 mA and the baffle is opened to start evaporation. After evaporation is completed, a chromium film with a thickness of 50 nm is obtained, which is the high-performance Li:NiO / ZnO / Si heterojunction ultraviolet detector.

[0093] Example 4: This embodiment is basically the same as Embodiment 1, except that a sputtering power of 200W is used when preparing the ZnO intermediate layer in this embodiment.

[0094] In this embodiment, a high-performance Li:NiO / ZnO / Si heterojunction ultraviolet detector fabricated on an n-type Si wafer includes the following steps: (1) Substrate treatment: An n-type Si wafer was selected and cut to a size of 19.5 mm × 19.5 mm with a thickness of 0.5 mm. The substrate was then ultrasonically treated in acetone, ethanol, and deionized water for 5 min each, and dried with high-purity nitrogen gas to obtain a clean and dry substrate. The cleaned substrate was then placed into the magnetron sputtering cavity. (2) Preparation of ZnO intermediate layer: The substrate processed in step (1) was sent into the magnetron sputtering cavity. A high-purity ZnO ceramic target with a purity of 99.99% was selected. A stainless steel mask with a rectangular opening (15.5 mm * 12.5 mm) was selected to cover the smooth surface of the substrate and then placed on the sample stage. After the sputtering cavity was evacuated, argon gas with a flow rate of 20 sccm was introduced. The sputtering pressure and sputtering power were set to 0.6 Pa and 200 W, respectively. After pre-sputtering for 15 min, the baffle was opened to start the formal sputtering. After the sputtering was completed, a ZnO intermediate layer with a thickness of 300 nm was obtained. (3) Preparation of lithium-doped NiO thin film: NiO ceramic target with lithium doping of 2 wt% was selected as the target material; a stainless steel mask plate with a rectangular opening (15.5 mm * 12.5 mm) was selected to cover the ZnO thin film surface, and the ZnO thin film sample obtained in step (2) was placed on the sample stage; after the sputtering chamber was evacuated, argon gas with a flow rate of 20 sccm was introduced; the sputtering pressure and sputtering power were set to 0.6 Pa and 60 W respectively, and the baffle was opened to start the formal sputtering after 15 min of pre-sputtering. After the sputtering was completed, a nickel oxide thin film layer with a thickness of 200 nm was obtained. (4) Fabrication of the upper electrode layer: The nickel oxide thin film sample obtained in step (3) is sent into the electron beam cavity. A nickel target is selected as the target material. A stainless steel mask plate with two square openings (4 mm * 4 mm) is selected to cover the nickel oxide thin film surface and then placed on the sample stage. After the cavity is evacuated, the electron gun beam current is adjusted to 60 mA and the baffle is opened to start evaporation. After evaporation is completed, a nickel thin film with a thickness of 50 nm is obtained. A chromium target is selected again, the electron gun beam current is adjusted to 15 mA and the baffle is opened to start evaporation. After evaporation is completed, a chromium thin film with a thickness of 50 nm is obtained.

[0095] (5) Fabrication of the bottom electrode layer: The sample obtained in step (4) is sent into the electron beam cavity. A titanium target is selected as the target material. A stainless steel mask with two square openings (4 mm * 4 mm) is selected to cover the smooth surface of the substrate and then placed on the sample stage. After the cavity is evacuated, the electron gun beam current is adjusted to 40 mA and the baffle is opened to start evaporation. After evaporation is completed, a titanium film with a thickness of 50 nm is obtained. A chromium target is selected again, the electron gun beam current is adjusted to 15 mA and the baffle is opened to start evaporation. After evaporation is completed, a chromium film with a thickness of 50 nm is obtained, which is the high-performance Li:NiO / ZnO / Si heterojunction ultraviolet detector.

[0096] Comparative Example 1 This comparative example provides a high-performance Li:NiO / Si heterojunction ultraviolet detector fabricated on an n-type Si wafer. Unlike Example 1, this comparative example does not perform step (2) ZnO intermediate layer preparation, but the rest is the same as Example 1.

[0097] Performance testing To evaluate the electrical and photoelectric response characteristics of the detectors prepared in Example 1 and Comparative Example 1, a 365nm LED pulsed light source was used for illumination, and a 5V reverse voltage was applied to both detectors (the titanium-chromium (Ti / Cr) composite electrode was connected to the positive terminal of the power supply). The electrical characteristics of the detectors obtained in Example 1 and Comparative Example 1 are as follows: The leakage current of the detector obtained in Example 1 is approximately 1*10⁻⁶. -6 A. Compared to the detector in Comparative Example 1 without a ZnO thin film (buffer) layer, the leakage current decreased by three orders of magnitude. The photoelectric response characteristics of the detectors obtained in Example 1 and Comparative Example 1 are as follows: The photocurrent-to-dark-current ratio of the detector obtained in Example 1 is approximately 1*10. 3 Compared to the detector in Comparative Example 1 without a ZnO buffer layer, the photocurrent-to-dark-current ratio increased by two orders of magnitude. This demonstrates that the high-performance Li:NiO / ZnO / Si heterojunction ultraviolet detector provided by this invention combines low dark current and low visible light response, thereby exhibiting high sensitivity.

[0098] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector, characterized in that, An n-type Si wafer, an n-type ZnO intermediate layer, and a lithium-doped p-type NiO thin film layer are stacked sequentially from bottom to top. An upper electrode layer is disposed on the upper surface of the lithium-doped p-type NiO thin film layer, and a bottom electrode layer is disposed on the area of ​​the n-type Si wafer not covered by the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer.

2. The high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector according to claim 1, characterized in that, The thickness of the n-type Si wafer is 0.5~2 mm, the thickness of the n-type ZnO intermediate layer is 10~500 nm, and the thickness of the lithium-doped p-type NiO thin film layer is 10~500 nm. The n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer have the same area, and the area of ​​the n-type Si wafer is larger than that of the n-type ZnO intermediate layer.

3. The high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector according to claim 1, characterized in that, The upper electrode layer is a nickel-chromium composite electrode layer, which includes a Ni thin film layer and a Cr thin film layer stacked sequentially, and the Ni thin film layer is in contact with the lithium-doped p-type NiO thin film layer; the bottom electrode layer is a titanium-chromium composite electrode layer, which includes a Ti thin film layer and a Cr thin film layer stacked sequentially, and the Ti thin film layer is in contact with the n-type Si wafer. In the upper electrode layer, the thickness of the Ni thin film layer is 5~100 nm, the thickness of the Cr thin film layer is 5~100 nm, and the Ni thin film layer and the Cr thin film layer have the same area. In the bottom electrode layer, the thickness of the Ti thin film layer is 5~100 nm, the thickness of the Cr thin film layer is 5~100 nm, and the areas of the Ti thin film layer and the Cr thin film layer are the same.

4. A high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector according to claim 1, characterized in that, In the lithium-doped p-type NiO thin film, the amount of lithium doping is 0.5~5wt%.

5. A method for fabricating a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Pretreatment of n-type Si wafers; S2. Sputter an n-type ZnO intermediate layer onto the pretreated n-type Si wafer using a mask and magnetron sputtering. S3. A lithium-doped p-type NiO thin film layer is sputtered on the n-type ZnO intermediate layer using a mask and magnetron sputtering. S4. An upper electrode layer was prepared on a lithium-doped p-type NiO thin film using a mask and electron beam evaporation. S5. In the area of ​​the pretreated n-type Si wafer not covered by the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer, a bottom electrode layer is prepared by means of a mask and electron beam evaporation to prepare the high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector.

6. The method for fabricating a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector according to claim 5, characterized in that, In step S2, the opening of the mask is rectangular, with dimensions of 12.5 mm * 9.5 mm to 15.5 mm * 12.5 mm. The magnetron sputtering uses a high-purity ZnO ceramic target with a purity higher than 99.99%, and the base vacuum of the magnetron sputtering is 2 * 10⁻⁶. -8 ~2*10 -6 Pa, the magnetron sputtering is performed in an argon atmosphere, the gas flow rate of the argon atmosphere is in the range of 10~100 sccm, the sputtering pressure is 0.3~1 Pa, and the sputtering power is 10~300 W; The sputtering process involves pre-sputtering for 1-30 minutes, followed by opening the baffle to begin formal sputtering, which lasts for 30-120 minutes. After sputtering is complete, the n-type ZnO intermediate layer is obtained.

7. The method for fabricating a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector according to claim 5, characterized in that, In step S3, the opening of the mask is rectangular, with dimensions of 12.5 mm * 9.5 mm to 15.5 mm * 12.5 mm. The magnetron sputtering uses a NiO ceramic target with a lithium doping content of 0.5 to 5 wt%, and the base vacuum of the magnetron sputtering is 2 * 10⁻⁶. -6 ~2*10 -4 Pa, the magnetron sputtering is performed in an argon atmosphere, the gas flow rate of the argon atmosphere is in the range of 10~100 sccm, the sputtering pressure is 0.3~1 Pa, and the sputtering power is 10~300 W; The sputtering process involves pre-sputtering for 1-30 minutes, then opening the baffle to begin formal sputtering, which lasts for 30-120 minutes. After sputtering is complete, the lithium-doped p-type NiO thin film layer is obtained.

8. The method for fabricating a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector according to claim 5, characterized in that, Step S4 specifically includes: firstly, a Ni thin film layer is prepared on a lithium-doped p-type NiO thin film layer using a mask and electron beam evaporation, and then a Cr thin film layer is prepared on the Ni thin film layer using the same mask-assisted electron beam evaporation. The opening of the mask is square, with dimensions of 2 mm*2 mm to 6 mm*6 mm. When preparing the Ni thin film, a high-purity nickel target with a purity higher than 99.99% is used, and the background vacuum degree of the electron beam evaporation is 2*10. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 40~80mA, the baffle is opened to start evaporation. After evaporation is complete, the Ni thin film layer is obtained. When preparing the Cr thin film, a high-purity chromium target with a purity higher than 99.99% is used, and the background vacuum degree of the electron beam evaporation is 2*10. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 10~20mA, the baffle is opened to start evaporation. After evaporation is completed, the upper electrode layer is obtained.

9. The method for fabricating a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector according to claim 5, characterized in that, Step S5 specifically includes: firstly, preparing a Ti thin film layer on the n-type Si wafer in the region not covered by the n-type ZnO intermediate layer and the lithium-doped p-type NiO thin film layer using a mask and electron beam evaporation method; then preparing a Cr thin film layer on the Ti thin film layer using the same mask-assisted electron beam evaporation method. The opening of the mask is square, with dimensions of 2 mm*2 mm to 6 mm*6 mm. When preparing the Ti thin film, a high-purity titanium target with a purity higher than 99.99% was used, and the background vacuum degree of the electron beam evaporation was 2*10. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 20~60mA, the baffle is opened to start evaporation. After evaporation is complete, the Ti thin film layer is obtained. When preparing the Cr thin film, a high-purity chromium target with a purity higher than 99.99% is used, and the background vacuum degree of the electron beam evaporation is 2*10. -6 ~2*10 -4 Pa, after adjusting the electron gun beam current to 10~20mA, the baffle is opened to start evaporation. After evaporation is complete, the bottom electrode layer is obtained.

10. The application of a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector as described in any one of claims 1 to 4 in the field of ultraviolet detection.

Images