CN114709282A - Photovoltaic InAsSb long-wave infrared detector material, preparation method and infrared detector - Google Patents

Abstract

The invention relates to a photovoltaic type InAsSb long-wave infrared detector material, a preparation method and an infrared detector, and belongs to the technical field of infrared detectors. The material structure is a pn structure composed of an InAs substrate, an n-type InAsSb layer and a p-type InAsSb layer. The preparation method only needs to grow an n-type InAsSb layer on an InAs substrate, and then form a p-type InAsSb layer through ion implantation or diffusion of doping elements, so as to form a pn junction. The method is simple, feasible and low in cost, and the prepared n-type InAsSb layer has a large thickness, which can effectively suppress lattice mismatch. The infrared detector is prepared by preparing a mesa on the basis of the material, and then growing a passivation film and a metal electrode, and has higher detection sensitivity than a photoconductive long-wave infrared detector.

Description

Photovoltaic InAsSb long-wave infrared detector material, preparation method and infrared detector

technical field

The invention relates to a photovoltaic type InAsSb long-wave infrared detector material, a preparation method and an infrared detector, and belongs to the technical field of infrared detectors.

Background technique

Indium arsenic antimony (InAsSb) is a III-V group antimony compound. Because of its strong covalent bonding force, it has good mechanical strength, chemical stability and long service life. In addition, InAsSb has a low room temperature Auger recombination coefficient and a high operating temperature, which has obvious advantages in the preparation of high temperature infrared detectors. Currently, the reported InAsSb infrared detectors are of two types: photoconductive and photovoltaic.

The material structure of the infrared detector in the photovoltaic InAsSb long-wave infrared detector in the prior art is usually a potential barrier structure, and there is a problem of difficulty in material growth, and it is difficult to obtain a long-wave infrared detector. At present, InAsSb long-wave infrared detectors are mainly photoconductive type, but the former InAsSb long-wave infrared detectors of photoconductive type have the defect of low detection sensitivity.

SUMMARY OF THE INVENTION

In order to overcome the defects of the prior art, one of the objectives of the present invention is to provide a photovoltaic type InAsSb long-wave infrared detector material, the material structure is an indium arsenide (InAs) substrate, an n-type InAsSb layer and a p-type InAsSb The pn structure composed of layers; the material has simple structure and low preparation difficulty, wherein the thickness of the n-type InAsSb layer is large, which can effectively suppress the lattice mismatch.

The second purpose of the present invention is to provide a method for preparing a photovoltaic type InAsSb long-wave infrared detector material. The preparation method only needs to grow an n-type InAsSb layer on an InAs substrate, and then form it by ion implantation or diffusion of doping elements. The p-type InAsSb layer can form a pn junction. The method is simple, feasible and low in cost, and the prepared n-type InAsSb layer has a large thickness, which can effectively suppress lattice mismatch.

The third object of the present invention is to provide a photovoltaic InAsSb long-wave infrared detector, by preparing a mesa on the basis of the photovoltaic-type InAsSb long-wave infrared detector material of the present invention, and then growing a passivation film and a metal Electrodes are obtained to obtain a photovoltaic InAsSb long-wave infrared detector, which has a higher detection sensitivity than a photoconductive long-wave infrared detector.

In order to achieve the purpose of the present invention, the following technical solutions are provided.

A photovoltaic type InAsSb long-wave infrared detector material, the material is a pn structure, composed of an InAs substrate, an n-type InAsSb layer and a p-type InAsSb layer in order from bottom to top, and the n-type InAsSb layer and the p-type InAsSb layer are formed between the layers pn junction.

The total thickness of the n-type InAsSb layer and the p-type InAsSb layer is 100 μm to 300 μm, wherein the thickness of the p-type InAsSb layer is 0.5 μm to 3 μm; preferably, the total thickness of the n-type InAsSb layer and the p-type InAsSb layer is 250 μm.

The material of the n-type InAsSb layer is n-type InAsSb single crystal material, the carrier concentration is 1×10 ¹⁵ cm ^-3 ～3×10 ¹⁶ cm ^-3 , and the electron mobility is 1×10 ⁴ cm ² /Vs～8× 10 ⁴ cm ² /Vs, and the response wavelength is 5 μm to 9 μm; preferably, the carrier concentration of the n-type InAsSb single crystal material is 2×10 ¹⁶ cm ⁻³ , and the electron mobility is 5×10 ⁴ cm ² /Vs.

The material of the p-type InAsSb layer is formed by ion-implanting or diffusing a doping element into the n-type InAsSb single crystal material, and the element is Mg, Be or Cd.

A preparation method of the photovoltaic type InAsSb long-wave infrared detector material according to the present invention, the method steps are as follows:

(1) An n-type InAsSb single crystal material with a thickness of 100 μm to 300 μm is grown on an InAs substrate by melt epitaxy, and the carrier concentration of the n-type InAsSb single crystal material is 1×10 ¹⁵ cm ^-3 ～ 3×10 ¹⁶ cm ^-3 , the electron mobility is 1×10 ⁴ cm ² /Vs～8×10 ⁴ cm ² /Vs, and the response wavelength is 5 μm～9 μm.

Preferably, the thickness of the n-type InAsSb single crystal material is 250 μm.

Preferably, the carrier concentration of the n-type InAsSb single crystal material is 2×10 ¹⁶ cm ⁻³ , and the electron mobility is 5×10 ⁴ cm ² /Vs.

(2) Using ion implantation doping elements or diffusion doping elements to form p-type InAsSb material on the upper surface of the n-type InAsSb single crystal material that is smooth, flat and without scratches, to obtain a p-type InAsSb layer, the n-type InAsSb single crystal The undoped element part in the lower part of the material is an n-type InAsSb layer, and a pn junction is formed between the p-type InAsSb layer and the n-type InAsSb layer, and a photovoltaic type InAsSb long-wave infrared detector material is prepared.

The depth of the doping element is 0.5 μm˜3 μm; the element is magnesium (Mg), beryllium (Be) or cadmium (Cd).

The dose of the ion implantation doping element is 1×10 ¹⁴ /cm ² ～8×10 ¹⁴ /cm ² ; preferably 2×10 ¹⁴ /cm ² , and the implantation energy is 100keV～300keV; Preferably, the ion implantation doping element is Be .

When diffusing the doping element, the diffusion temperature is 400°C to 450°C, and the diffusion time is 4h to 5h; preferably, the element to be diffused and doped is Cd.

The upper surface of the n-type InAsSb single crystal material that is smooth, flat and free from scratches can be obtained by polishing with a polishing liquid.

A photovoltaic type InAsSb long-wave infrared detector, by further preparing a mesa on the basis of the photovoltaic type InAsSb long-wave infrared detector material of the present invention, and then growing a passivation film on the mesa, and then removing the growth electrode. The passivation film formed ohmic holes, and metal electrodes were grown from the openings of the ohmic holes to form a photovoltaic InAsSb long-wave infrared detector.

A preparation method of a photovoltaic type InAsSb long-wave infrared detector according to the present invention, the method steps are as follows:

(1) On the surface of the p-type InAsSb layer in the photovoltaic type InAsSb long-wave infrared detector material of the present invention, use mask lithography to form a mesa pattern, and form a mesa by wet etching or/and etching technology ;

Preferably, the depth of the mesa is larger than the depth of the ion-implanted dopant element or the diffused dopant element.

(2) Wet etching is used to remove the surface damage of the P-type InAsSb layer after doping.

Preferably, a solution prepared by mixing hydrogen peroxide, hydrofluoric acid (HF) and water in a volume ratio of 1:1:(4-10) is used as the etching solution for wet etching.

The preferred etching time is 5s to 30s.

(3) Grow a passivation film on the mesa, remove the passivation film at the two growing metal electrodes to form ohmic holes, grow two metal electrodes from the openings of the ohmic holes, and one metal electrode is located on the p-type InAsSb layer , the other metal electrode is located on the n-type InAsSb layer.

The passivation film is preferably grown by plasma chemical vapor deposition, electron beam evaporation or magnetron sputtering.

The passivation film material is the passivation film material used by the long-wave infrared detector in the prior art, and preferably the passivation film material is one or both of SiO ₂ , Si ₃ N ₄ and ZnS.

The thickness of the passivation film is preferably 100 nm to 2000 nm.

Preferably, the passivation film at the growth metal electrode is removed by plasma etching, so as to realize the opening of the ohmic hole, and the ohmic contact is formed after the growth of the metal electrode.

Preferably, the metal electrode is prepared by photolithography and magnetron sputtering technology. Electrode patterns are formed on the p-type InAsSb layer and the n-type InAsSb layer by a photolithography mask, and the shape and position of the metal electrode are fixed. The metal electrode is deposited by a sputtering coater; finally, the excess deposited metal is removed by metal stripping or etching to form a metal electrode, and a photovoltaic type InAsSb long-wave infrared detector is prepared.

Preferably, the material of the metal electrode is chrome gold, and the thickness of the metal electrode is 400 nm˜800 nm.

beneficial effect

1. The present invention provides a photovoltaic type InAsSb long-wave infrared detector material, the material is a pn structure, and is sequentially composed of an InAs substrate, an n-type InAsSb layer and a p-type InAsSb layer from bottom to top, and the n-type InAsSb layer and the p-type InAsSb layer. A pn junction is formed between the n-type InAsSb layers; the material has a simple structure and low preparation difficulty, and the n-type InAsSb layer has a large thickness, which can effectively suppress lattice mismatch; the material of the present invention does not use the photovoltaic type InAsSb long-wavelength in the prior art The barrier structure commonly used in the infrared detector material overcomes the difficulty of growing the photovoltaic InAsSb long-wave infrared detector material with the barrier structure, and the problem that the InAsSb long-wave infrared detector cannot be prepared.

2. The present invention provides a method for preparing a photovoltaic type InAsSb long-wave infrared detector material. The preparation method only needs to grow an n-type InAsSb material on an InAs substrate, and then dope the n-type InAsSb material by ion implantation. Elements or diffusion doping elements form a p-type InAsSb layer, the undoped element in the lower part of the n-type InAsSb material is an n-type InAsSb layer, and a pn junction can be formed between the two layers; the method is simple, feasible and low in cost, In addition, the prepared n-type InAsSb layer has a large thickness, which can effectively suppress the lattice mismatch; it overcomes the difficulty of growing the photovoltaic InAsSb long-wave infrared detector material with the current barrier structure, and the problem that the photovoltaic-type InAsSb long-wave infrared detector cannot be prepared.

3. The present invention provides a photovoltaic InAsSb long-wave infrared detector. The photovoltaic InAsSb long-wave infrared detector is prepared by techniques such as photolithography, wet etching or etching, passivation, etc. The high detection sensitivity overcomes the defect of low sensitivity of the photoconductive InAsSb long-wave infrared detector.

Description of drawings

1 is the X-ray diffraction pattern of the n-type InAsSb single crystal material grown on the InAs substrate in Examples 1 and 2.

FIG. 2 is a schematic structural diagram of the photovoltaic InAsSb long-wave infrared detector materials prepared in Examples 1 and 2. FIG.

3 is a schematic structural diagram of the photovoltaic InAsSb long-wave infrared detectors prepared in Examples 3 and 4.

4 is the spectral response line of the photovoltaic InAsSb long-wave infrared detector prepared in Example 3 at 150K.

FIG. 5 is the spectral response curve of the photovoltaic InAsSb long-wave infrared detector prepared in Example 4 at 150K.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but it is not intended to limit the patent of the present invention.

In the following examples:

PM6 precision grinding and polishing machine, Logitech, UK.

Ion implanter, the 48th Research Institute of China Electronics Technology Group Corporation.

Diffusion furnace, Qingdao Sereda Electronic Equipment Co., Ltd.

MA6 lithography machine, SUSS, Germany.

MPS type automatic magnetron sputtering coating machine, Beijing Jinsheng Micro-nano Technology Co., Ltd.

Infrared detector spectral response test system, Beijing Zhuoli Hanguang Instrument Co., Ltd.

The polishing liquid is prepared by mixing silica sol, water and hydrogen peroxide in a volume ratio of 10:10:1.

Example 1

A preparation method of a photovoltaic type InAsSb long-wave infrared detector material, the method steps are as follows:

(1) An n-type InAsSb single crystal material with a thickness of 250 μm is grown on an InAs substrate by melt epitaxy. The carrier concentration of the InAsSb single crystal material is 2×10 ¹⁶ cm ^-3 , and the electron mobility is 5×10 ⁴ cm ² /Vs, and the response wavelength is 5 μm to 9 μm.

(2) A polyurethane polishing disc is installed on the PM6 precision grinding and polishing machine, and the upper surface of the n-type InAsSb single crystal material is polished with a polishing liquid. During polishing, the dripping rate of the polishing liquid is 3 drops/second, and the pressure is 80 g/cm ² , the rotation speed is 20rpm; after polishing for 15min, rinse the upper surface of the n-type InAsSb single crystal material with pure water, and dry it with high-purity nitrogen with a purity of 99.999% to obtain a smooth, flat and scratch-free upper surface;

The lattice constant of the n-type InAsSb single crystal material was obtained by X-ray diffraction test, and its lattice mismatch was calculated to be 5.69%, as shown in Figure 1.

Inductively coupled plasma chemical vapor deposition (ICPCVD) equipment was used to deposit a SiO ₂ protective film with a thickness of 100 nm on the surface of the n-type InAsSb single crystal material that was clean, flat and scratch-free.

An ion implanter was used to implant the dopant element Be into the material through the upper surface of the n-type InAsSb single crystal material deposited with the SiO ₂ protective film, the implant energy was 150keV, the implant dose was 2×10 ¹⁴ /cm ² , and the ion implantation doped The depth of the impurity Be element is 1 μm; a p-type InAsSb material is formed to obtain a p-type InAsSb layer, and the part of the lower part of the n-type InAsSb single crystal material that is not ion-implanted and doped with Be elements is the n-type InAsSb layer, the p-type InAsSb layer and the n-type InAsSb layer A pn junction is formed between the InAsSb layers, and a photovoltaic type InAsSb long-wave infrared detector material is prepared. As shown in Figure 2, the material is a pn structure, which is composed of an InAs substrate, an n-type InAsSb layer and a p type InAsSb layer composition.

Example 2

A preparation method of a photovoltaic type InAsSb long-wave infrared detector material, the method steps are as follows:

(1) An n-type InAsSb single crystal material with a thickness of 250 μm is grown on an InAs substrate by melt epitaxy. The carrier concentration of the InAsSb single crystal material is 2×10 ¹⁶ cm ^-3 , and the electron mobility is 5×10 ⁴ cm ² /Vs, and the response wavelength is 5 μm to 9 μm.

(2) A polyurethane polishing disc is installed on the PM6 precision grinding and polishing machine, and the upper surface of the n-type InAsSb single crystal material is polished with a polishing liquid. During polishing, the dripping rate of the polishing liquid is 3 drops/second, and the pressure is 80 g/cm ² , the rotation speed is 20rpm; after polishing for 15min, rinse the upper surface of the n-type InAsSb single crystal material with pure water, and dry it with high-purity nitrogen with a purity of 99.999% to obtain a smooth, flat and scratch-free surface; then by X-ray diffraction The lattice constant of the n-type InAsSb single crystal material is obtained through testing, and its lattice mismatch degree is calculated to be 5.69%, as shown in FIG. 1 .

Use a diffusion furnace to diffuse Cd elements into the interior of the material through the upper surface of the smooth, flat and scratch-free n-type InAsSb single crystal material, the diffusion temperature is (430±1) °C, and the diffusion time is 4.5h; The depth of the impurity Cd element is 2 μm, forming a p-type InAsSb material to obtain a p-type InAsSb layer, and the undoped Cd element part in the lower part of the n-type InAsSb single crystal material is an n-type InAsSb layer, p-type InAsSb layer and n-type InAsSb layer A pn junction is formed between them, and a photovoltaic type InAsSb long-wave infrared detector material is prepared. The structure is shown in Figure 2. The material is a pn structure. layer composition.

Example 3

A preparation method of a photovoltaic type InAsSb long-wave infrared detector, the method steps are as follows:

(1) Mix hydrofluoric acid and water in a volume ratio of 1:5 to prepare a corrosive solution, and use wet etching to remove the p-type InAsSb layer in a photovoltaic type InAsSb long-wave infrared detector material prepared in Example 1 SiO ₂ protective film on the upper surface, the etching time is 2min.

A mesa pattern was formed on the upper surface of the p-type InAsSb layer described in the MA6 lithography machine and the mask, and hydrogen peroxide, hydrofluoric acid (HF) and water were mixed in a volume ratio of 1:1:5 to prepare an etching solution, The mesa was formed by wet etching, and the etching time was 6s; the depth of the mesa was 1.5 μm.

(2) Hydrogen oxide, hydrofluoric acid and water are mixed in a volume ratio of 1:1:10 to prepare an etching solution, and the surface of the P-type InAsSb layer is damaged after removing the doping elements by wet etching, and the etching time is 10s.

(3) A layer of ZnS passivation film was grown on the mesa with an MPS type automatic magnetron sputtering coater, and the thickness of the passivation film was 800 nm; the ZnS passivation at the two growing metal electrodes was removed by plasma etching technology film to realize ohmic hole opening, the etching power is 150W, and the etching time is 14min.

Use an MA6 lithography machine to form electrode patterns on the surface of the pn junction through a photolithography mask, and fix the shape and position of the metal electrodes. One metal electrode is connected to the p-type InAsSb layer, and the other metal electrode is connected to the n-type InAsSb layer. MPS type automatic magnetron sputtering coater deposits chromium/gold electrodes with a thickness of 600 nm, wherein the thickness of the chromium film is 100 nm; the thickness of the gold film is 500 nm; then soaked in acetone for 15 minutes, rinsed with ethanol for 5 minutes, and peeled off the surface The excess metal and acetone remained to form a chromium/gold electrode, and a photovoltaic InAsSb long-wave infrared detector was prepared, the structure of which is shown in Figure 3.

A photovoltaic type InAsSb long-wave infrared detector prepared in this embodiment is tested as follows:

The spectral response test of the long-wave infrared detector was carried out using an infrared detector spectral response test system, and the test was carried out at ^150K .

Example 4

A preparation method of a photovoltaic type InAsSb long-wave infrared detector, the method steps are as follows:

(1) A mesa pattern is formed on the upper surface of the p-type InAsSb layer in a photovoltaic type InAsSb long-wave infrared detector material prepared in Example 2 by using an MA6 lithography machine and a mask, and a mesa is formed by reactive plasma etching technology, The etching power was 200W, the etching time was 20min, and the mesa depth was 2.5μm.

(2) Hydrogen oxide, hydrofluoric acid and water are mixed in a volume ratio of 1:1:10 to prepare an etching solution, and wet etching is used to remove the damage on the surface of the P-type InAsSb layer after doping elements, and the etching time is 10s.

(3) A layer of ZnS passivation film was grown on the mesa with an MPS type automatic magnetron sputtering coater, and the thickness of the passivation film was 800 nm; the ZnS passivation film at the two growth electrodes was removed by plasma etching technology , in order to realize ohmic hole opening, the etching power is 150W, and the etching time is 14min.

Use an MA6 lithography machine to form electrode patterns on the surface of the pn junction through a photolithography mask, and fix the shape and position of the metal electrodes. One metal electrode is connected to the p-type InAsSb layer, and the other metal electrode is connected to the n-type InAsSb layer. MPS type automatic magnetron sputtering coater deposits chromium/gold electrodes with a thickness of 600nm, wherein the thickness of the chromium film is 100nm and the thickness of the gold film is 500nm; then soaked in pure acetone for 15min, then rinsed with ethanol for 5min to peel off the surface The excess metal and acetone remain to form a metal electrode, and a photovoltaic InAsSb long-wave infrared detector is prepared, the structure of which is shown in Figure 3.

A photovoltaic type InAsSb long-wave infrared detector prepared in this embodiment is tested as follows:

The spectral response test of the long-wave infrared detector was carried out using an infrared detector spectral response test system, and the test was performed at ^150K .

Claims (10)

1. a photovoltaic type InAsSb long-wave infrared detector material, it is characterized in that: described material is made up of InAs substrate, n-type InAsSb layer and p-type InAsSb layer sequentially from bottom to top, and between n-type InAsSb layer and p-type InAsSb layer A pn junction is formed between them. 2 . The photovoltaic type InAsSb long-wave infrared detector material according to claim 1 , wherein the total thickness of the n-type InAsSb layer and the p-type InAsSb layer is 100 μm to 300 μm, wherein the thickness of the p-type InAsSb layer is 0.5 μm. 3 . μm～3μm. 3. A photovoltaic type InAsSb long-wave infrared detector material according to any one of claims 1 and 2, wherein the material of the n-type InAsSb layer is an n-type InAsSb single crystal material, and the carrier concentration is 1 ×10 ¹⁵ cm ^-3 ～3×10 ¹⁶ cm ^-3 , electron mobility is 1×10 ⁴ cm ² /Vs～8×10 ⁴ cm ² /Vs, response wavelength is 5μm～9μm; material of p-type InAsSb layer It is formed by ion implanting or diffusing a doping element into the n-type InAsSb single crystal material, and the element is Mg, Be or Cd. 4. The preparation method of a photovoltaic type InAsSb long-wave infrared detector material according to claim 3, wherein the total thickness of the n-type InAsSb layer and the p-type InAsSb layer is 250 μm; the n-type InAsSb single crystal material The carrier concentration is 2×10 ¹⁶ cm ^-3 and the electron mobility is 5×10 ⁴ cm ² /Vs. 5. A method for preparing a photovoltaic type InAsSb long-wave infrared detector material according to any one of claims 1 to 4, wherein the method steps are as follows: (1) An n-type InAsSb single crystal material with a thickness of 100 μm to 300 μm is grown on an InAs substrate by melt epitaxy, and the carrier concentration of the n-type InAsSb single crystal material is 1×10 ¹⁵ cm ^-3 ～ 3×10 ¹⁶ cm ^-3 , electron mobility is 1×10 ⁴ cm ² /Vs～8×10 ⁴ cm ² /Vs, response wavelength is 5μm～9μm; (2) Using ion implantation doping elements or diffusion doping elements to form p-type InAsSb material on the upper surface of the n-type InAsSb single crystal material that is smooth, flat and without scratches, to obtain a p-type InAsSb layer, the n-type InAsSb single crystal An n-type InAsSb layer is formed in the undoped element part of the lower part of the material, and a pn junction is formed between the p-type InAsSb layer and the n-type InAsSb layer, and a photovoltaic type InAsSb long-wave infrared detector material is prepared; The depth of the doping element is 0.5 μm～3 μm; the element is Mg, Be or Cd; When ions are implanted with doping elements, the implantation dose is 1×10 ¹⁴ /cm ² ～8×10 ¹⁴ /cm ² , and the implantation energy is 100keV～300keV; When diffusing doping elements, the diffusion temperature is 400℃～450℃, and the diffusion time is 4h～5h. 6 . The method for preparing a photovoltaic type InAsSb long-wave infrared detector material according to claim 5 , wherein the thickness of the n-type InAsSb single crystal material is 250 μm, and the carrier concentration is 2×10 ¹⁶ cm 6 . ^-3 , the electron mobility is 5×10 ⁴ cm ² /Vs. 7. The method for preparing a photovoltaic type InAsSb long-wave infrared detector material according to claim 5 or 6, characterized in that: when ions are implanted with doping elements, the implantation dose is 2×10 ¹⁴ /cm ² ; When ions are implanted with doping elements, the doping element is Be; When the doping element is diffused, the doped element is Cd; The upper surface of the n-type InAsSb single crystal material that is smooth, flat and free from scratches is obtained by polishing with a polishing liquid. 8. A photovoltaic-type InAsSb long-wave infrared detector, characterized in that: on the basis of a photovoltaic-type InAsSb long-wave infrared detector material according to any one of claims 1 to 4, a mesa is further prepared, and then a A passivation film is grown on the mesa, an ohmic hole is formed by removing the passivation film at the growth electrode, and a metal electrode is grown from the opening of the ohmic hole to form a photovoltaic InAsSb long-wave infrared detector. 9. a preparation method of photovoltaic type InAsSb long-wave infrared detector as claimed in claim 8 is characterized in that: described method steps are as follows: (1) On the surface of the p-type InAsSb layer in the photovoltaic-type InAsSb long-wave infrared detector material, a mesa pattern is formed by mask lithography, and a mesa is formed by wet etching or/and etching technology; (2) Use wet etching to remove the surface damage of the P-type InAsSb layer after doping; (3) Grow a passivation film on the mesa, remove the passivation film at the two growing metal electrodes to form ohmic holes, grow two metal electrodes from the openings of the ohmic holes, and one metal electrode is located on the p-type InAsSb layer , another metal electrode is located on the n-type InAsSb layer, and a photovoltaic type InAsSb long-wave infrared detector is prepared. 10 . The method for preparing a photovoltaic InAsSb long-wave infrared detector according to claim 9 , wherein the depth of the mesa is greater than the depth of the ion-implanted doping element or the diffusion doping element; 11 . The solution prepared by mixing hydrogen peroxide, hydrofluoric acid and water according to the volume ratio of 1:1:(4～10) is used as the etching solution for wet etching; the etching time is 5s～30s; The passivation film is grown by plasma chemical vapor deposition, electron beam evaporation or magnetron sputtering; The passivation film material is one or both of SiO ₂ , Si ₃ N ₄ and ZnS; the thickness of the passivation film is 100nm～2000nm; Use plasma etching to remove passivation at the growing metal electrode; The metal electrodes are prepared by photolithography and magnetron sputtering techniques. Electrode patterns are formed on the p-type InAsSb layer and the n-type InAsSb layer by photolithography masks, and the shape and position of the metal electrodes are fixed, and then magnetron sputtering is used. The metal electrode is deposited by the spray coating machine; finally, the excess deposited metal is removed by metal stripping or etching to form a metal electrode; The material of the metal electrode is chrome gold, and the thickness of the metal electrode is 400 nm to 800 nm.

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