Photoelectric detector based on micro-nano folded substrate and preparation method thereof

Abstract

The invention belongs to the technical field of semiconductors, and particularly discloses a photoelectric detector based on a micro-nano wrinkled substrate and a preparation method thereof, and the preparation method comprises the following steps: carrying out the pretreatment of a silicon wafer, and obtaining a silicon substrate; wherein the silicon wafer comprises monocrystalline silicon at the lower layer and silicon oxide at the upper layer; a magnesium metal layer is deposited on the silicon oxide of the silicon substrate through vacuum thermal evaporation, the upper surface of the magnesium metal layer is oxidized through ultraviolet ozone, and a wrinkled micro-nano structure is prepared; molybdenum sulfide obtained through mechanical stripping is transferred and attached to the wrinkled micro-nano structure on the upper surface of the magnesium metal layer through a dry method, and a source electrode and a drain electrode are deposited on the surface of the molybdenum sulfide through an electron beam evaporation coating system. The photoelectric detector based on the micro-nano folded substrate has the advantages of being simple in preparation process, high in response speed, good in reliability, high in stability and the like.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a photodetector based on a micro-nano wrinkled substrate and a preparation method thereof. Background Art

[0002] The performance optimization of photodetectors has long been restricted by the dual constraints of the inherent properties of semiconductor materials and the device structure design. In traditional planar devices, the light absorption efficiency of the semiconductor layer is significantly restricted due to the insufficient effective optical path length. At the same time, photo-generated carriers experience multiple scattering and recombination processes during the extended migration path, resulting in an increase in the transport time of photo-generated carriers. The two jointly restrict the response speed of the device. The wrinkled micro-nano structure can reduce the scattering of carriers and improve the carrier mobility. For example, by lithography or nanoimprinting to construct a photonic crystal structure on the substrate surface, the light absorption efficiency can be enhanced; by using epitaxial strain engineering to induce lattice distortion of the semiconductor, the carrier transport characteristics can be optimized. However, such methods rely on complex processes, such as multi-step lithography, high-temperature annealing, etc., with high costs and difficult to achieve large-area uniform processing. In addition, traditional stress engineering mostly relies on external mechanical loading or heteroepitaxy, which is easy to introduce interface defects and lead to uncontrollable structures.

[0003] Magnesium, as a highly active metal, has significant volume expansion characteristics and lattice mismatch effects (lattice constant difference Δa = 0.101 nm) during the oxidation process, providing unique advantages for the self-organization formation of controllable micro-nano wrinkled structures. However, existing research mostly focuses on the anti-corrosion coating or energy storage applications of magnesium, and the potential of its structure-function integration in the optoelectronic field is insufficiently explored. In particular, the lack of coordinated regulation of the magnesium oxidation stress release mechanism leads to the difficulty in accurately matching the wavelength, amplitude, and spatial distribution of the wrinkled structure with the optical and mechanical requirements of the photodetector. Summary of the Invention

[0004] In view of the above existing deficiencies, the present invention provides a photodetector based on a micro-nano wrinkled substrate and a preparation method thereof. The present invention precisely regulates the thickness, oxidation atmosphere, and thermodynamic parameters of the magnesium metal layer, and uses the compressive stress during the magnesium oxidation process to form a wrinkled structure. This structure has both photonic crystal effects and strain engineering characteristics, improving the mobility. At the same time, the wavy morphology of its wrinkled substrate can disperse external mechanical stress. Compared with traditional processes, the present invention abandons complex lithography and external loading steps, realizing the "material-structure-function" integrated design, and providing an innovative solution for the low-cost and large-scale manufacturing of high-performance photodetectors. The photodetector based on the micro-nano wrinkled substrate of the present invention has the advantages of simple preparation process, fast response rate, good reliability, and high stability.

[0005] To achieve the above object, the present invention provides a preparation method of a photodetector based on a micro-nano wrinkled substrate, including the following steps: S1. After pre-treating the silicon wafer, a silicon substrate is obtained. Among them, the silicon wafer includes single-crystalline silicon in the lower layer and silicon oxide in the upper layer. S2. On the silicon oxide of the silicon substrate, a magnesium metal layer is deposited by vacuum thermal evaporation. The upper surface of the magnesium metal layer is oxidized by ultraviolet ozone to prepare a wrinkled micro-nano structure. S3. The molybdenum disulfide obtained by mechanical exfoliation is dry-transferred and bonded to the wrinkled micro-nano structure on the upper surface of the magnesium metal layer, and a source electrode and a drain electrode are deposited on the surface of the molybdenum disulfide by an electron beam evaporation coating system.

[0006] According to one aspect of the present invention, in step S1, the pre-treatment is: the silicon wafer is ultrasonically cleaned with acetone, isopropyl alcohol and deionized water respectively, and then dried by gradient heating.

[0007] According to one aspect of the present invention, the gradient heating includes a first temperature, a second temperature, a third temperature and a fourth temperature; the first temperature is 40 °C, and the holding time at the first temperature is 8 - 12 min; the second temperature is 55 °C, and the holding time at the second temperature is 8 - 12 min; the third temperature is 80 °C, and the holding time at the third temperature is 8 - 12 min; the fourth temperature is 110 °C, and the holding time at the fourth temperature is 8 - 12 min.

[0008] It should be noted that gradient heating can avoid micro-cracks in the silicon oxide layer of the silicon wafer or interface delamination of the silicon wafer caused by sudden temperature changes. At the same time, due to the different boiling points of acetone, isopropyl alcohol and deionized water, we choose gradient heating to also avoid water marks or the like on the upper surface of the silicon wafer during the drying process, resulting in unevenness.

[0009] According to one aspect of the present invention, in step S1, the single-crystalline silicon is p-heavily doped silicon.

[0010] It should be noted that p-heavily doped silicon is used as the conductive layer, and silicon oxide is used as the insulating layer.

[0011] It should be noted that the silicon wafer in step S1 can be directly purchased.

[0012] Exemplarily, the silicon wafer in step S1 is a single-polished silicon oxide wafer (P-type) of Suzhou Jingsi Electronic Technology Co., Ltd.

[0013] According to one aspect of the present invention, in step S2, the deposition rate of the vacuum thermal evaporation is 0.01 - 0.02 nm / s, the vacuum degree of the vacuum thermal evaporation is 1×10 -4 ~8×10 -5 Pa, and the thickness of the magnesium metal layer is 3 - 5 nm.

[0014] According to one aspect of the present invention, in step S2, the temperature of the ultraviolet ozone oxidation is 30 to 60 °C, the ozone concentration of the ultraviolet ozone oxidation is 50 to 100 ppm, the ozone flow rate of the ultraviolet ozone oxidation is 0.5 to 1.2 L / min, and the time of the ultraviolet ozone oxidation is 3 to 8 min.

[0015] Exemplarily, the device for the ultraviolet ozone oxidation is an ultraviolet ozone cleaning machine.

[0016] Exemplarily, the device for the ultraviolet ozone oxidation is an SC-UV-I type ultraviolet ozone cleaning machine.

[0017] According to one aspect of the present invention, in step S3, both the source electrode and the drain electrode are composed of two layers of materials, including chromium in the lower layer and gold in the upper layer.

[0018] According to one aspect of the present invention, the electron beam evaporation coating system includes an electron beam exposure system and a thermal evaporation system.

[0019] It should be noted that the electron beam evaporation coating equipment all consists of two parts (an electron beam exposure system and a thermal evaporation system).

[0020] According to one aspect of the present invention, the source electrode / drain electrode is first chromium-sputtered through the electron beam exposure system, and then gold is evaporated on the upper surface of the chromium through the thermal evaporation system.

[0021] Based on the same inventive concept, the present invention also provides a photodetector based on a micro-nano wrinkled substrate, which is prepared by the preparation method described in any one of the above.

[0022] The present invention also provides the beneficial effects of the present invention: (1) The wrinkled substrate generated by the oxidation-induced stress mismatch of magnesium metal in the present invention can optimize the energy band structure of molybdenum sulfide, reduce the energy of the conduction band bottom of molybdenum sulfide, increase the energy of the valence band top, reduce the band gap width, enhance the carrier injection efficiency, and thus effectively improve the carrier mobility. That is, the present invention solves the problem of low carrier concentration in metal oxide transistors and greatly improves the performance of the transistors.

[0023] (2) The wrinkled surface (wrinkled micro-nano structure) of the present invention acts as a photonic crystal. Through scattering and local state resonance, the incident light is confined in the active layer, the equivalent optical path is extended, the thickness of the molybdenum sulfide layer at the wrinkled trough is thinned, a quantum confinement effect is formed, the carrier migration path is shortened, and the transit time is reduced, achieving the effect of improving the light response speed. The present invention solves the problem of slow response speed of thin film transistor photodetectors and greatly improves the performance of the photodetectors. The structure of the present invention is simple, the manufacturing cost is low, the performance is excellent, and the application range is wide. Brief Description of the Drawings

[0024] Figure 1 Schematic diagram of a photodetector based on a micro-nano wrinkled substrate according to the present invention; Figure 2 Atomic force microscope scan of the wrinkled micro-nano structure of the photodetector of Example 1 of the present invention; among them, (a) is the atomic force microscope scan of the wrinkled micro-nano structure on the upper surface of the magnesium metal layer of Example 1; (b) is the atomic force microscope scan after molybdenum disulfide is transferred onto the wrinkled micro-nano structure of Example 1; Figure 3 Atomic force microscope scan of the photodetector of Comparative Example 1 of the present invention; among them, (a) is the atomic force microscope scan of the upper surface of the aluminum metal layer of Comparative Example 1; (b) is the atomic force microscope scan after molybdenum disulfide is transferred onto the upper surface of the aluminum metal layer of Comparative Example 1; Figure 4 Atomic force microscope scan of the photodetector of Comparative Example 2 of the present invention; among them, (a) is the atomic force microscope scan of the silicon dioxide surface on the silicon wafer of Comparative Example 2; (b) is the atomic force microscope scan after molybdenum disulfide is transferred onto the silicon dioxide surface of Comparative Example 2; Figure 5 Atomic force microscope images of the wrinkled micro-nano structures of the photodetectors of Example 1, Comparative Example 1 or Comparative Example 2 of the present invention, and optical performance test and electrical performance test diagrams after being fabricated into devices; among them, (a) is the atomic force microscope image and amplitude of the wrinkled micro-nano structure of the photodetector of Example 1; (b) is the transfer curves of the photodetectors of Example 1 and Comparative Example 2 under voltages from -60 V to 60 V; (c) is the change diagram of the transfer characteristic curve of the photodetector of Example 1 under the condition of incident light with a wavelength of 457 nm and a source-drain voltage of 1 V; (d) is the optical response time diagram of the photodetector of Example 1 under the condition of incident light with a wavelength of 457 nm and a gate voltage of -60 V; (e) is the response time of the rising edge and falling edge of the photocurrent of the photodetector of Example 1.

[0025] Explanation of reference numerals: 1a, single crystal silicon; 1b, silicon dioxide; 2, magnesium metal layer; 2a, expanded magnesium metal; 3, molybdenum disulfide; 4a, source electrode; 4b, drain electrode. Detailed implementation manners

[0026] To make the present invention easier to understand, the present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present invention. Unless otherwise defined, the professional terms used below have the same meaning as understood by those of ordinary skill in the art; unless otherwise specified, the raw materials and reagents involved in this article can be purchased from the market or prepared by known methods.

[0027] It should be noted that V involved in the drawings of this application ds 、V gs are all common knowledge in the art, that is, V ds is the drain-source voltage; V gs is the gate-source voltage.

[0028] In order to solve the problems of complex preparation process and low response rate of existing photodetectors, the inventors of this application provide a photodetector based on a micro-nano wrinkled substrate, specifically as Figure 1 shown, a silicon wafer, a magnesium metal layer 2, molybdenum disulfide 3, a source electrode 4a / drain electrode 4b are stacked in sequence from bottom to top; wherein, the silicon wafer includes a single-crystalline silicon 1a in the lower layer and a silicon oxide 1b in the upper layer; the magnesium metal layer 2 includes a magnesium metal substrate and a wrinkled micro-nano structure (metallic magnesium 2a after volume expansion) on the upper surface of the magnesium metal substrate; the single-crystalline silicon 1a serves as the gate; the thickness of the magnesium metal layer 2 is 3-5 nm.

[0029] The inventors of this application also provide a method for preparing a photodetector based on a micro-nano wrinkled substrate, including the following steps: S1. After the silicon wafer is pretreated, a silicon substrate is obtained; wherein, the silicon wafer includes a single-crystalline silicon 1a in the lower layer and a silicon oxide 1b in the upper layer; S2. A magnesium metal layer 2 is vacuum thermally evaporated and deposited on the silicon oxide 1b of the silicon substrate, and the upper surface of the magnesium metal layer 2 is oxidized by ultraviolet ozone to prepare a wrinkled micro-nano structure (metallic magnesium 2a after volume expansion); S3. The mechanically exfoliated molybdenum disulfide 3 is dry-transferred and bonded to the wrinkled micro-nano structure (metallic magnesium 2a after volume expansion) on the upper surface of the magnesium metal layer, and a source electrode 4a and a drain electrode 4b are deposited on the surface of the molybdenum disulfide by electron beam evaporation coating.

[0030] Preferably, in step S1, the pretreatment is as follows: the silicon wafer is ultrasonically cleaned with acetone, isopropyl alcohol, and deionized water respectively, and then dried by gradient heating. The gradient heating includes a first temperature, a second temperature, a third temperature, and a fourth temperature; the first temperature is 40 °C, and the holding time at the first temperature is 8 - 12 min; the second temperature is 55 °C, and the holding time at the second temperature is 8 - 12 min; the third temperature is 80 °C, and the holding time at the third temperature is 8 - 12 min; the fourth temperature is 110 °C, and the holding time at the fourth temperature is 8 - 12 min. In step S1, the single-crystalline silicon is p-heavily doped silicon. In step S2, the deposition rate of the vacuum thermal evaporation is 0.01 - 0.02 nm / s, and the vacuum degree of the vacuum thermal evaporation is 1x10 -4 ~8x10 -5 Pa. In step S2, the temperature of the ultraviolet ozone oxidation is 30 - 60 °C, the ozone concentration of the ultraviolet ozone oxidation is 50 - 100 ppm, the ozone flow rate of the ultraviolet ozone oxidation is 0.5 - 1.2 L / min, and the time of the ultraviolet ozone oxidation is 3 - 8 min. In step S3, both the source electrode and the drain electrode are composed of two layers of materials, including chromium in the lower layer and gold in the upper layer. The electron beam evaporation coating system includes an electron beam exposure system and a thermal evaporation system. The source electrode / drain electrode is first chromium-plated through the electron beam exposure system, and then gold is evaporated on the upper surface of the chromium through the thermal evaporation system.

[0031] The following is further elaborated in combination with specific examples and comparative examples.

[0032] Example 1 A preparation method of a photodetector based on a micro-nano wrinkled substrate includes the following steps: Step 1: Ultrasonically clean the silicon wafer (the lower p-heavily doped silicon and the upper silicon oxide, purchased from Suzhou Jingsi Electronic Technology Co., Ltd.) with acetone, isopropyl alcohol, and deionized water respectively, and the ultrasonic time in deionized water is 2 min. Then transfer the silicon wafer to a vacuum drying oven and dry it by gradient heating for 20 min to obtain a clean silicon substrate. Among them, the gradient heating is to keep warm at 40 °C, 55 °C, 80 °C, and 110 °C for 10 min in sequence.

[0033] Step 2: Deposit on the upper surface of the silicon oxide insulating layer of the silicon substrate by using a thermal resistance evaporation coating system (the temperature in the vacuum chamber is maintained at 25 °C, and the pressure in the vacuum chamber is maintained at 1×10 -4A 5-nm magnesium metal layer (deposition rate: 0.1 nm / s) was deposited on Pa, and then it was transferred to a SC-UV-I type ultraviolet ozone cleaning machine. Under the conditions of a main wavelength of 185 nm and a secondary wavelength of 254 nm of the ultraviolet lamp, oxygen was introduced with an oxygen flow rate of 0.8 L / min. The discharge power was adjusted to 45 w, the ozone concentration was controlled at 70 ppm, and the chamber temperature was 40 °C for oxidation for 6 min to obtain a wrinkled micro-nano structure on the upper surface of the magnesium metal layer.

[0034] Step 3: Gently press the tape with molybdenum disulfide crystals (Scotch tape, purchased from 3M Company) with your finger, attach the molybdenum disulfide to the prepared wrinkled micro-nano structure, and let it stand for 15 min. First, chromium was deposited on the source electrode / drain electrode through an electron beam exposure system, and then gold was evaporated on the upper surface of chromium through a thermal evaporation system. Among them, the thickness of the lower layer of chromium of the source electrode / drain electrode is 10 nm, and the thickness of the upper layer of gold of the source electrode / drain electrode is 50 nm.

[0035] Comparative Example 1 (replacing Mg with metal Al) A method for preparing a photodetector includes the following steps: Step 1: The silicon wafer (the lower p-heavily doped silicon and the upper silicon oxide, purchased from Suzhou Jingsi Electronic Technology Co., Ltd.) was ultrasonically cleaned with acetone, isopropyl alcohol, and deionized water respectively, and the ultrasonic time in deionized water was 2 min. Subsequently, the silicon wafer was transferred to a vacuum drying oven and dried by gradient heating for 20 min to obtain a clean silicon substrate. Among them, the gradient heating was to keep warm at 40 °C, 55 °C, 80 °C, and 110 °C for 10 min in sequence.

[0036] Step 2: Deposit (the temperature in the vacuum chamber was maintained at 25 °C, and the pressure in the vacuum chamber was maintained at 1×10 -4 Pa, deposition rate: 0.1 nm / s) a 5-nm aluminum metal layer on the upper surface of the silicon oxide insulating layer of the silicon substrate, and then transfer it to a SC-UV-I type ultraviolet ozone cleaning machine. Under the conditions of a main wavelength of 185 nm and a secondary wavelength of 254 nm of the ultraviolet lamp, oxygen was introduced with an oxygen flow rate of 0.8 L / min. The discharge power was adjusted to 45 w, the ozone concentration was controlled at 70 ppm, and the chamber temperature was 40 °C for oxidation for 6 min to obtain an aluminum oxide layer on the upper surface of the aluminum metal layer.

[0037] Step 3: Gently press the tape with molybdenum disulfide crystals (Scotch tape, purchased from 3M Company) with your finger, place the molybdenum disulfide on the prepared alumina layer, and let it stand for 15 min. First, use the source electrode / drain electrode to deposit chromium through an electron beam exposure system, and then evaporate gold on the upper surface of chromium through a thermal evaporation system. Among them, the thickness of the lower chromium layer of the source electrode / drain electrode is 10 nm, and the thickness of the upper gold layer of the source electrode / drain electrode is 50 nm.

[0038] Comparative Example 2 (without depositing a magnesium metal layer and without ultraviolet ozone oxidation) A method for preparing a photodetector, comprising the following steps: Step 1: Ultrasonically clean the silicon wafer (the lower p-heavily doped silicon and the upper silicon oxide, purchased from Suzhou Jingsi Electronic Technology Co., Ltd.) with acetone, isopropyl alcohol, and deionized water respectively, and ultrasonically clean in deionized water for 2 min. Subsequently, transfer the silicon wafer to a vacuum drying oven and dry it by gradient heating for 20 min to obtain a clean silicon substrate. Among them, the gradient heating is to keep warm at 40 °C, 55 °C, 80 °C, and 110 °C for 10 min in sequence.

[0039] Step 2: Gently press the tape with molybdenum disulfide crystals (Scotch tape, purchased from 3M Company) with your finger, place the molybdenum disulfide on the silicon oxide insulating layer of the silicon wafer, and let it stand for 15 min. First, use the source electrode / drain electrode to deposit chromium through an electron beam exposure system, and then evaporate gold on the upper surface of chromium through a thermal evaporation system. Among them, the thickness of the lower chromium layer of the source electrode / drain electrode is 10 nm, and the thickness of the upper gold layer of the source electrode / drain electrode is 50 nm.

[0040] Performance detection and result analysis: Perform atomic force scanning electron microscopy analysis on the photodetectors prepared in Example 1 and Comparative Examples 1-2, and the results are as Figures 2 - 4 shown. From Figure 2 (a) and Figure 2 (b) comparison, it can be seen that obvious wrinkles are formed on the surface of the magnesium metal layer oxidized by ultraviolet ozone in Example 1 of the present invention, and after transferring molybdenum disulfide on the wrinkles, the molybdenum disulfide also has a relatively obvious wrinkled structure. From Figure 3 (a) and Figure 3 (b) comparison, it can be seen that only slight wrinkles are formed on the surface of the aluminum metal layer oxidized by ultraviolet ozone in Comparative Example 1 of the present invention, and after transferring molybdenum disulfide on the wrinkles, the molybdenum disulfide also only has a slight wrinkled structure. From Figure 4 (a) and Figure 4(b) By comparison, it can be seen that the silicon dioxide on the silicon substrate has no wrinkles, and after transferring molybdenum disulfide onto the silicon dioxide, the molybdenum disulfide also has no obvious wrinkled structure. The photodetectors prepared in Example 1 and Comparative Examples 1-2 were tested for wrinkling amplitude, carrier mobility, and optical response time, and the results are shown in Table 1 and Figure 5 as follows.

[0041] Table 1 Detection results of wrinkling amplitude, carrier mobility, and optical response time of the photodetectors in Example 1 and Comparative Examples 1-2 ; As can be seen from Table 1, the magnesium oxide wrinkled substrate on the magnesium metal layer in Example 1 of this application significantly improves the carrier mobility and optical response speed through a unique surface structure and magnesium layer design. In Comparative Examples 1 and 2, due to the smooth substrates (aluminum oxide in Comparative Example 1 and silicon dioxide in Comparative Example 2), the structure has serious interface scattering or insufficient light absorption, resulting in low carrier mobility and slow optical response. This result also demonstrates the importance of the micro-nano structure of materials in device optimization. From Figure 5 (a), it can be seen that the amplitude of the photodetector in Example 1 is 3-6 nm, showing periodic fluctuations, indicating the high roughness and wrinkled interface characteristics of the upper surface of the magnesium metal layer. From Figure 5 (b), it can be seen that the carrier mobility of the device based on the magnesium oxide wrinkled substrate in Example 1 is significantly higher than that of the device with a silicon dioxide substrate in Comparative Example 2. From Figure 5 (c), it can be seen that under 457 nm light illumination, the transfer curve of the photodetector in Example 1 shows an obvious shift and the current amplitude increases, indicating that the photo-generated carriers of the photodetector in Example 1 can be effectively separated and regulated. From Figure 5 (d)- Figure 5 (e) and Literature 1 (Ding S, Liu C, Li Z, et al. Ag-assisted dry exfoliation of large-scale and continuous 2D monolayers[J]. ACS nano, 2023, 18(1): 1195-1203.) By comparison, the rise time (7 ms) and fall time (22 ms) of the photocurrent of the photodetector in Example 1 are much faster than those of the device with a silicon dioxide substrate in Literature 1 and the repeatability of the response curve is high, indicating the reliability and stability of the photodetector of this application under dynamic working conditions.

[0042] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims described above.

Claims

1. A method for preparing a photodetector based on a micro-nano wrinkled substrate, characterized in that, It includes the following steps: S1. After pre-treating the silicon wafer, a silicon substrate is obtained; wherein, the silicon wafer includes single-crystalline silicon in the lower layer and silicon oxide in the upper layer; S2. A magnesium metal layer is deposited on the silicon oxide of the silicon substrate by vacuum thermal evaporation, and the upper surface of the magnesium metal layer is oxidized by ultraviolet ozone to prepare a wrinkled micro-nano structure; S3. The molybdenum disulfide obtained by mechanical exfoliation is dry-transferred and bonded to the wrinkled micro-nano structure on the upper surface of the magnesium metal layer, and a source electrode and a drain electrode are deposited on the surface of the molybdenum disulfide by an electron beam evaporation coating system.

2. The preparation method of the photodetector based on the micro-nano wrinkled substrate according to claim 1, wherein, In step S1, the pre-treatment is: ultrasonically cleaning the silicon wafer with acetone, isopropyl alcohol and deionized water respectively, and then drying it by gradient heating.

3. The preparation method of the photodetector based on the micro-nano wrinkled substrate according to claim 2, characterized in that, The gradient heating includes a first temperature, a second temperature, a third temperature and a fourth temperature; the first temperature is 40 °C, and the holding time at the first temperature is 8 - 12 min; the second temperature is 55 °C, and the holding time at the second temperature is 8 - 12 min; the third temperature is 80 °C, and the holding time at the third temperature is 8 - 12 min; the fourth temperature is 110 °C, and the holding time at the fourth temperature is 8 - 12 min.

4. The preparation method of the photodetector based on the micro-nano wrinkled substrate according to claim 1, characterized in that, In step S1, the single-crystalline silicon is p-heavily doped silicon.

5. The preparation method of the photodetector based on the micro-nano wrinkled substrate according to claim 1, characterized in that, In step S2, the deposition rate of the vacuum thermal evaporation is 0.01~0.02 nm / s, the vacuum degree of the vacuum thermal evaporation is 1×10 -4 ~8×10 -5 Pa, and the thickness of the magnesium metal layer is 3~5 nm.

6. The preparation method of the photodetector based on the micro-nano wrinkled substrate according to claim 1, wherein, In step S2, the temperature of the ultraviolet ozone oxidation is 30 - 60 °C, the ozone concentration of the ultraviolet ozone oxidation is 50 - 100 ppm, the ozone flow rate of the ultraviolet ozone oxidation is 0.5 - 1.2 L / min, and the time of the ultraviolet ozone oxidation is 3 - 8 min.

7. The preparation method of the photodetector based on the micro-nano wrinkled substrate according to claim 1, wherein In step S3, both the source electrode and the drain electrode are composed of two layers of materials, including chromium in the lower layer and gold in the upper layer.

8. The manufacturing method of the photodetector based on a micro-nano wrinkled substrate according to claim 7, characterized in that, The electron beam evaporation coating system includes an electron beam exposure system and a thermal evaporation system.

9. The preparation method of the photodetector based on the micro-nano wrinkled substrate according to claim 8, wherein, The source electrode / drain electrode is first chromium-sputtered by the electron beam exposure system, and then gold is evaporated on the upper surface of the chromium by the thermal evaporation system.

10. A photodetector based on a micro-nano wrinkled substrate, characterized in that, Prepared by the preparation method according to any one of claims 1 - 9.

Images