High-gain short-wave infrared photoelectric detector based on metal-silicon micro-nano structure and preparation method of high-gain short-wave infrared photoelectric detector

Abstract

The invention relates to a high-gain short-wave infrared photoelectric detector based on a metal-silicon micro-nano structure and a preparation method of the high-gain short-wave infrared photoelectric detector, and belongs to the technical field of photoelectric detection. The detector comprises a first metal film layer, a silicon film layer and a second metal film layer which are sequentially arranged, the junction formed by the first metal film layer and the silicon film layer and the junction formed by the second metal film layer and the silicon film layer are independently Schottky junctions or ohmic junctions, and the junction formed by the first metal film layer and the silicon film layer and the junction formed by the second metal film layer and the silicon film layer are not ohmic junctions at the same time; the silicon film layer is of a micro-nano structure, and the thickness of the silicon film layer ranges from 50 nm to 5000 nm. The first metal film layer or the second metal film layer is provided with a micro-nano structure consistent with or corresponding to the silicon film layer. Near-infrared light in the wave band of 1100-2000 nm can be detected, a high-strength electric field can be established in the silicon film layer under small bias voltage, photoconductive gain and an avalanche multiplication effect are further introduced, and the photoelectric response characteristic of hot electrons in the near-infrared wave band is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of photoelectric detection technology, and particularly relates to a high-gain short-wave infrared photodetector based on a metal-silicon micro-nano structure and its fabrication method. Background Technology

[0002] Silicon-based infrared photodetectors, due to their excellent compatibility with complementary metal-oxide-semiconductor (CMOS) processes, exhibit significant cost advantages and technical feasibility in the field of electro-optical integration. Currently, they play an irreplaceable role in several key areas, including data transmission, night vision imaging, biomedical detection, and automotive radar systems. However, limited by the 1.1 eV bandgap of silicon, traditional silicon-based infrared photodetectors have inherent limitations, making it difficult to directly detect near-infrared (NIR) photons with wavelengths greater than 1100 nm. This deficiency significantly restricts their application in a wider range of spectral detection scenarios. In recent years, hot carrier photodetectors (HCPDs) have gradually attracted widespread attention in the scientific research field due to their unique photoelectric conversion mechanism and ability to detect sub-bandgap photons, and are regarded as a potential solution to overcome the spectral detection limitations of traditional silicon-based infrared photodetectors. However, existing hot carrier photodetectors still face key performance bottlenecks. The low light absorption efficiency and hot electron injection efficiency severely restrict the improvement of the overall detection performance of the device, making it difficult to meet the requirements of high-sensitivity detection in practical applications. To improve the response performance of hot-carrier photodetectors, researchers have constructed various metal nanostructures, aiming to enhance light absorption by exciting surface plasmon resonance effects, thereby improving the generation and injection efficiency of hot electrons. For example, Cheng Zhang et al. designed a gold-coated silicon nanocone structure, utilizing a mixed plasmon mode along the conical tip to achieve a certain degree of field enhancement and broadband response; Wen L et al. designed a micro-mass platform based on gold-coated disordered silicon nanoholes (SiNHs) to promote broadband energy conversion of hot electrons, achieving a photoresponsivity of approximately 1.5 mA / W-13 mA / W in the 1100 nm-1500 nm wavelength range. However, such micro-nano structure-based improvement schemes have limited effect on improving device responsivity, typically only a few times, and the complex fabrication processes of micro-nano structures significantly increase the cost and difficulty of device fabrication, hindering large-scale production and practical application. In summary, current hot-carrier photodetectors face key challenges such as limited broadband spectral response, difficulty in adapting to complex spectral environments, and low photoelectric conversion efficiency, which restricts device detection capabilities. Furthermore, traditional silicon-based infrared photodetectors require a hundred-volt bias voltage to achieve gain, resulting in high voltage requirements and high energy consumption. Therefore, developing a silicon-based hot-carrier photodetector that is easy to fabricate, can effectively extend the detection wavelength to the near-infrared band, and possesses broadband response, high absorption rate, and high gain characteristics has significant research value and broad application prospects. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a high-gain short-wave infrared photodetector based on a metal-silicon micro / nano structure and its fabrication method. A silicon film layer with a micro / nano structure and a thickness of hundreds of nanometers is fabricated using wet and dry plasma etching processes. This process avoids the complex photolithography required for traditional periodic micro / nano structures, significantly reducing process difficulty and manufacturing costs. Furthermore, the detector consists of a first metal film layer, a silicon film layer, and a second metal film layer, capable of detecting near-infrared light in the 1100nm-2000nm band. Due to the thinness of the silicon film layer, a high-intensity electric field can be established within it under a small bias voltage, thereby introducing photoconductivity gain and avalanche multiplication effect, significantly improving the photoelectric response characteristics of hot electrons in the near-infrared band.

[0004] The first objective of this invention is to provide a high-gain short-wave infrared photodetector based on a metal-silicon micro / nano structure, comprising a first metal film layer, a second metal film layer disposed on the first metal film layer, and a silicon film layer disposed between the first metal film layer and the second metal film layer; The junction formed by the first metal film layer and the silicon film layer, and the junction formed by the second metal film layer and the silicon film layer are independently either Schottky junctions or ohmic junctions, and the junction formed by the first metal film layer and the silicon film layer, and the junction formed by the second metal film layer and the silicon film layer are not simultaneously ohmic junctions; The silicon film has a micro / nano structure; the lateral feature size of the micro / nano structure is 100nm-3000nm, and the thickness of the silicon film is 50nm-5000nm; preferably, the thickness of the silicon film is 50nm-1000nm. The first or second metal film layer has a micro / nano structure that is consistent with or corresponds to the silicon film layer. Introducing a micro / nano structure on the surface of the silicon film layer allows it to naturally form a corresponding metal film layer micro / nano structure during subsequent metal deposition. This metal-silicon composite micro / nano structure can effectively excite surface plasmon resonance, significantly enhance the interaction between light and matter, and thus achieve excellent light absorption characteristics over a wide wavelength range. Furthermore, the hot carriers generated in the metal can be injected into the silicon film layer and collected to form a photocurrent, enabling effective detection of short-wave infrared light with energy lower than the silicon bandgap.

[0005] In one embodiment of the present invention, the micro / nano structure is selected from one or more of the following: disordered hole array, disordered trench array, disordered island array, disordered cone array, ordered hole array, and ordered pyramid array. By designing micro / nano structures in the silicon film layer, the surface plasmon resonance effect can be effectively enhanced, thereby significantly improving the device responsivity. The working mechanism of the device is as follows: the first metal film layer (bottom electrode layer) and the second metal film layer (top electrode layer) absorb near-infrared light and generate hot carriers. These carriers then cross the potential barrier of the metal-silicon Schottky junction and are injected into the silicon film layer, and are finally collected to form a photocurrent, realizing efficient detection of infrared light with energy lower than the silicon bandgap.

[0006] In one embodiment of the present invention, the materials of the first metal film layer and the second metal film layer are independently selected from one or more of titanium, gold, silver, copper, chromium and aluminum; and the materials of the first metal film layer and the second metal film layer are different.

[0007] In one embodiment of the present invention, the thickness of the first metal film layer is greater than 10 nm; preferably 50 nm-200 nm. The thickness of the second metal film is 5nm-100nm.

[0008] In one embodiment of the present invention, the silicon film layer is made of lightly doped N-type crystalline silicon or lightly doped P-type crystalline silicon. And / or, the resistivity of the silicon film is 0.1Ω·cm-100Ω·cm.

[0009] A second objective of this invention is to provide a method for fabricating the high-gain short-wave infrared photodetector based on the metal-silicon micro / nano structure, comprising the following steps: S1. The pretreated silicon on the insulator is placed in hydrofluoric acid solution to remove the insulating layer. Then, the obtained silicon film is placed in seed solution to grow silver particles. Subsequently, the silicon is etched by plasma and the silver particles are removed by nitric acid solution to obtain a silicon film layer with micro-nano structure. S2. A first metal film and a second metal film are prepared on the lower and upper surfaces of the silicon film respectively by physical methods to obtain the high-gain short-wave infrared photodetector based on the metal-silicon micro-nano structure.

[0010] In one embodiment of the present invention, before S1, the following steps are further included: after homogenizing the silicon top of the pretreated insulator, the silicon is thinned, polished, plated with a back electrode, coated with SU8 and bonded with an adhesive film, and the silicon dioxide is removed by plasma etching.

[0011] In one embodiment of the present invention, in S1, the pretreatment involves ultrasonically cleaning the silicon on the insulator using an organic solvent and water in sequence.

[0012] In one embodiment of the present invention, in S1, the seed solution includes silver nitrate, hydrofluoric acid, and deionized water.

[0013] In one embodiment of the present invention, in S2, the physical method is selected from magnetron sputtering deposition and / or electron beam evaporation.

[0014] The technical solution of the present invention has the following advantages compared with the prior art: The high-gain short-wave infrared photodetector based on a metal-silicon micro / nano structure described in this invention has a multi-layer structure and is insensitive to polarization and incident angle. Furthermore, by adjusting the material composition of the first metal film layer (bottom electrode layer) or the second metal film layer (top electrode layer), it can form a synergistic light absorption mechanism with the silicon film layer having a micro / nano structure, thereby flexibly achieving broadband coverage absorption in the near-infrared band or narrowband high-selectivity absorption of specific wavelengths to meet the application needs of different fields.

[0015] The high-gain short-wave infrared photodetector based on a metal-silicon micro / nano structure described in this invention achieves a responsivity of 0.1 A / W to 0.84 A / W in the 1100 nm to 2000 nm near-infrared band under a bias voltage of 0.1 V to 1.5 V. When a bias voltage is applied, a high-intensity electric field is formed between the silicon film layers and the metal film layers. Charge carriers are energized and accelerated in the electric field, generating photoconductivity gain and avalanche multiplication effect, which increases the photocurrent by 3 to 4 orders of magnitude, thereby improving the photoelectric responsivity to near-infrared light. For example, under a small bias voltage of 1.2 V, the responsivity of this detector in the 1300 nm band can reach 0.78 A / W, which is four orders of magnitude higher than the zero bias state.

[0016] The high-gain short-wave infrared photodetector based on a metal-silicon micro / nano structure of the present invention consists of a first metal film layer, an ultrathin silicon film layer with micro / nano structures, and a second metal film layer. Due to the thinness of the silicon film layer, fabricating micro / nano structures on it is very difficult. This process can achieve the fabrication of micro / nano structures through stable wet or dry etching. The ultrathin silicon film layer, through micro / nano structure designs such as hole arrays, trench arrays, and island arrays, can significantly enhance the confinement effect of infrared light in the silicon-based material and the light-matter interaction, greatly improving the light absorption efficiency. Furthermore, the synergy between this micro / nano structure and the ultrathin silicon can increase the generation of photogenerated electrons and promote the excitation of plasmons, thereby generating more charge carriers when a small bias voltage is applied, which is beneficial for promoting the avalanche effect and thus producing a high-gain effect. The overall structure is simple and the fabrication process is highly compatible. Attached Figure Description

[0017] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a schematic diagram of the high-gain short-wave infrared photodetector based on a metal-silicon micro / nano structure prepared in Example 1 of the present invention. Figure 2 This is a flowchart illustrating the fabrication of a high-gain short-wave infrared photodetector based on a metal-silicon micro / nano structure in Example 1 of the present invention. Figure 3 These are surface morphology images of (a) after silver particles are grown and (b) after silver particles are removed in Test Example 1 of the present invention; Figure 4 The absorption / reflection spectrum (a) and dark-state current-voltage curve (b) of the high-gain short-wave infrared photodetector based on the metal-silicon micro / nano structure in Test Example 2 of this invention are shown; where the solid line is the absorption rate curve and the dashed line is the reflectance curve. Figure 5 The photocurrent-time curves (a) of the high-gain short-wave infrared photodetector based on the metal-silicon micro / nano structure in Test Example 3 of the present invention for near-infrared laser in the 1100nm-2000nm band at zero bias and the responsivity curve (b) for the 1100nm-1800nm ​​band at zero bias are shown. Figure 6 The photocurrent-time curves (a) of the high-gain short-wave infrared photodetector based on a metal-silicon micro / nano structure prepared in Example 1 of Test Example 4 of this invention under different bias voltages in the 1100nm-2000nm band, and the responsivity curves (b) of the detector under bias voltage and a commercial indium gallium arsenide detector under zero bias in the 1100nm-1800nm ​​band; where the dotted line represents the detector and the square dotted line represents the commercial indium gallium arsenide detector; Figure 7 The responsivity curves of the detectors prepared in Comparative Example 1(a) and Example 1(b) in Test Example 5 of the present invention are shown. Explanation of reference numerals in the attached figures: 1-first metal film layer, 2-silicon film layer, 3-second metal film layer. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0019] In this invention, unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. "Comprising" or "containing" as used in this invention means that it may include or contain other components in addition to the stated components. "Comprising" or "containing" as used in this invention may also be replaced with the closed form "is" or "consisting of". Example 1

[0020] Reference Figure 1 As shown, the high-gain short-wave infrared photodetector based on a metal-silicon micro / nano structure of the present invention comprises, from bottom to top, the following components arranged sequentially: First metal film layer 1 (bottom electrode layer): includes a 5nm thick titanium film layer, a 70nm thick gold film layer, and a 120nm thick aluminum film layer stacked sequentially from bottom to top; Silicon film layer 2: has a micro / nano structure with a lateral feature size of 200 nm and a thickness of 100 nm, and a resistivity of 1 Ω·cm-20 Ω·cm; The second metal film layer 3 (top electrode layer) includes a 2nm thick titanium film layer and a 15nm thick gold film layer stacked sequentially from bottom to top. The second metal film layer 3 has the same micro-nano structure as the silicon film layer 2; The first metal film layer 1 and the silicon film layer 2 form a first Schottky junction, and the second metal film layer 3 and the silicon film layer 2 form a second Schottky junction; and the barrier height of the first Schottky junction is different from the barrier height of the second Schottky junction; The fabrication process of the high-gain short-wave infrared photodetector based on the metal-silicon micro / nano structure is as follows: Figure 2 As shown, a polished silicon oxide wafer with a top layer of silicon oxide of 300nm thickness is used as the substrate, specifically including the following steps: S1. A commercial silicon-on-insulation (SOI) substrate that has been ultrasonically cleaned with acetone, ethanol and deionized water is placed in a 40% hydrofluoric acid solution. After removing the silicon oxide layer of the insulating layer, an ultrathin silicon film is obtained suspended in the solution. S2. The ultrathin silicon film is transferred to the surface of a substrate spin-coated with PMMA and air-dried; then, a 120nm thick aluminum film layer is deposited on the surface of the ultrathin silicon film using magnetron sputtering (pre-sputtering is performed for 5 minutes before deposition, with a vacuum degree of 5×10⁻⁶). -4 The process parameters for magnetron sputtering are: aluminum target, power 50W, argon gas is introduced during sputtering, and the pressure inside the cavity is 1Pa), resulting in an ultrathin silicon film containing an aluminum film layer. S3. The ultrathin silicon film containing the aluminum film layer is transferred to acetone and allowed to stand. It is then transferred onto a titanium-gold film layer (including a 5nm thick titanium film layer and a 70nm thick gold film layer) and air-dried to prepare an ultrathin silicon film containing the first metal film layer. Both the titanium and gold film layers are prepared using electron beam evaporation (pre-sputtering for 5 minutes before deposition; the electron beam evaporation process parameters are: evaporation rate 0.5A / s, pre-evaporation power 30%, evaporation power 30%, and working vacuum 5e). -4 Pa (operating temperature 20℃) S4. Coat a layer of photoresist on the ultrathin silicon film containing the first metal film layer, and expose a window smaller than the silicon film layer using an ultraviolet exposure system. Then, grow silver particles using a wet method with a seed solution (198 mg AgNO3 and 13 mL HF, prepared into a 50 mL solution with deionized water) for a reaction time of 5 s. Then, etch trenches approximately 20 nm deep using a plasma etching machine (working vacuum 5e). -4 Pa (operating temperature 20℃); then the device was immersed in nitric acid solution for 20s to remove silver particles, and then successively immersed in deionized water and acetone solution to remove photoresist. After standing for a period of time, it was taken out and air-dried to prepare a silicon film layer with micro-nano structure. S5. A layer of photoresist is then coated onto the silicon film with micro / nano structures. A window smaller than the silicon film is exposed using an ultraviolet exposure system. Then, a 2nm thick titanium film and a 15nm thick gold film are deposited using electron beam evaporation (pre-sputtering for 5 minutes is performed before deposition; the electron beam evaporation process parameters are: titanium and gold targets, evaporation rate of 0.5A / s, and working vacuum of 5e). -4 Pa (operating temperature 20℃), then the device was immersed in acetone solution, left to stand for a period of time, and then taken out and air-dried to prepare a high-gain short-wave infrared photodetector based on metal-silicon micro-nano structure. Comparative Example 1

[0021] It is basically the same as Example 1, except that there are no micro-nano structures on the silicon film layer. Test Example 1

[0022] Based on Example 1, the surface morphology after the growth of silver particles and the removal of silver particles was characterized, and the results are as follows: Figure 3 As shown. From Figure 3 It can be seen that there is a disordered array of trenches with a size of about 200 nm on the surface of the silicon film. This disordered trench array structure can achieve higher light absorption by increasing the number of light reflections on the device surface and exciting surface plasmons. Test Example 2

[0023] (1) The optical absorptivity and reflectivity of the high-gain short-wave infrared photodetector based on the metal-silicon micro / nano structure prepared in Example 1 were tested using a spectrometer. The results are as follows: Figure 4 As shown in (a). From Figure 4 (a) It can be seen that the average absorption rate of the detector in the 1100nm-1800nm ​​near-infrared band exceeds 60%, indicating that the detector can achieve broadband absorption in this band.

[0024] (2) The electrical response of the metal-silicon micro / nano structure high-gain short-wave infrared photodetector prepared in Example 1 was tested using a micro-area testing platform. The dark-state current-voltage curve of the detector in the voltage range of -1V to 1V is shown in the figure. Figure 4 As shown in (b). From Figure 4 (b) It can be seen that the top metal film of the detector forms a Schottky junction with the silicon film with a high potential barrier, while the silicon film forms a Schottky junction with the bottom metal film with a low potential barrier. Test Example 3

[0025] (1) Under the test conditions of zero bias and periodically switched light source, the photocurrent-time curves of the high-gain short-wave infrared photodetector based on metal-silicon micro / nano structure prepared in Example 1 for near-infrared light of different wavelengths in the range of 1100nm-2000nm are as follows. Figure 5 As shown in (a). From Figure 5 (a) It can be seen that the detector exhibits a significant photoelectric response throughout the entire test band.

[0026] (2) To further analyze its spectral response characteristics, the photocurrent and corresponding laser output power of the detector were measured at a denser wavelength interval. The responsivity curve is shown in the figure. Figure 5 As shown in (b). From Figure 5 (b) It can be seen that the detector has broadband light absorption capability in the 1100nm-1800nm ​​near-infrared band. Test Example 4

[0027] (1) The photocurrent-time curves of the high-gain short-wave infrared photodetector based on metal-silicon micro / nano structure prepared in Example 1 under different bias voltages and laser irradiation in the 1100nm-2000nm (100nm interval) band are as follows: Figure 6 As shown in (a). From Figure 6 (a) It can be seen that the photocurrent at 1300nm under a bias voltage of -1.2V reaches 1600μA, which is 2700 times higher than the 0.58μA photocurrent at 1300nm under a bias voltage of 0V.

[0028] (2) The responsivity curves of the high-gain short-wave infrared photodetector based on the metal-silicon micro / nano structure prepared in Example 1 under bias voltage and the commercial indium gallium arsenide detector under zero bias voltage were tested in the 1100nm-1800nm ​​band. The results are as follows: Figure 6 As shown in (b). From Figure 6 (b) It can be seen that the responsivity of this detector is on the same order of magnitude as that of commercial detectors, and its responsivity is higher than that of commercial indium gallium arsenide detectors in some bands. Test Example 5

[0029] Under the same bias voltage (-1.2V), the responsivity curves of the detectors prepared in Comparative Example 1 and Example 1 are as follows: Figure 7 As shown. From Figure 7 (a) It can be seen that the responsivity of Comparative Example 1 gradually increases in the 1200nm-1800nm ​​band, reaching a relatively high value near 1800nm, indicating that the detector's light response capability in the long-wave near-infrared region (close to 1800nm) gradually increases. From Figure 7 (b) It can be seen that the responsivity of Example 1 rises rapidly in the 1200nm-1500nm range and reaches a peak (approximately 0.84 A / W), followed by a rapid decline in the 1500nm-1800nm ​​band. This indicates that the detector of Example 1 has more outstanding photoresponse performance in the mid-wave near-infrared region (1200nm-1500nm) and a higher peak responsivity.

[0030] In summary, the high-gain short-wave infrared photodetector based on metal-silicon micro / nano structure of the present invention can meet different application requirements by adjusting the micro / nano structure; and the detector can generate an avalanche multiplication effect when a bias voltage is applied, which greatly improves the photoresponsivity of the device.

[0031] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A high gain short-wave infrared photodetector based on metal-silicon micro- nanostructures, characterized in that, The metal-silicon micro-nano structure-based high-gain short-wave infrared photodetector comprises a first metal film layer, a second metal film layer disposed on the first metal film layer, and a silicon film layer disposed between the first metal film layer and the second metal film layer; The junction formed by the first metal film layer and the silicon film layer and the junction formed by the second metal film layer and the silicon film layer are independently a Schottky junction or an ohmic junction, and the junction formed by the first metal film layer and the silicon film layer and the junction formed by the second metal film layer and the silicon film layer are not ohmic junctions at the same time; The silicon film layer has a micro-nano structure; the lateral characteristic size of the micro-nano structure is 50 nm-3000 nm, and the thickness of the silicon film layer is 50 nm-5000 nm; The first metal film layer or the second metal film layer has a micro-nano structure consistent with or corresponding to the silicon film layer.

2. The metal-silicon micro / nanostructure-based high-gain short-wave infrared photodetector according to claim 1, wherein, The micro-nano structure is selected from one or more of an unordered pore array, an unordered trench array, an unordered island array, an unordered cone array, an ordered pore array, and an ordered pyramid array. 3.The high-gain short-wave infrared photodetector based on metal-silicon micro / nano structures of claim 1, wherein, The material of the first metal film layer and the second metal film layer is independently selected from one or more of titanium, gold, silver, copper, chromium, and aluminum; and the materials of the first metal film layer and the second metal film layer are different. 4.The high-gain short-wave infrared photodetector based on metal-silicon micro / nano structures of claim 1, wherein, The thickness of the first metal film layer is greater than 10 nm; The thickness of the second metal film layer is 5 nm-100 nm.

5. The metal-silicon micro / nanostructure-based high-gain short-wave infrared photodetector of claim 1, wherein, The material of the silicon film layer is a lightly doped N-type crystalline silicon material or a lightly doped P-type crystalline silicon material; And / or, the resistivity of the silicon film layer is 0.1 Ω·cm-100 Ω·cm.

6. The method for preparing high-gain short-wave infrared photodetector based on metal-silicon micro-nano structures according to any one of claims 1-5, wherein, The method comprises the following steps: S1, placing the pretreated silicon-on-insulator in a hydrofluoric acid solution to remove the insulating layer, then placing the obtained silicon film in a seed solution to grow silver particles, and then performing plasma etching of silicon and removing the silver particles with a nitric acid solution to obtain a silicon film layer with a micro-nano structure; S2, preparing a first metal film layer and a second metal film layer on the lower surface and the upper surface of the silicon film layer, respectively, by a physical method, to obtain the metal-silicon micro-nano structure-based high-gain short-wave infrared photodetector.

7. The method for preparing metal-silicon micro-nano structure based high gain short-wave infrared photodetector according to claim 6, characterized in that, Before S1, the following steps are further included: after uniformly coating the top of the pretreated silicon-on-insulator, sequentially performing thinning, polishing, back electrode plating, SU8 coating, and adhesive film lamination, and then removing the silicon dioxide by plasma etching.

8. The method for preparing metal-silicon micro-nano structure based high gain short-wave infrared photodetector according to claim 6, characterized in that, In S1, the pretreatment is ultrasonic cleaning of the silicon-on-insulator with organic solvents and water.

9. The method for preparing metal-silicon micro-nano structure based high gain short-wave infrared photodetector according to claim 6, characterized in that, In S1, the seed solution comprises silver nitrate, hydrofluoric acid, and deionized water.

10. The method for fabricating metal-silicon micro-nano structure based high gain short-wave infrared photodetector according to claim 6, wherein, In S2, the physical method is selected from magnetron sputtering deposition and / or electron beam evaporation.

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