Thin-layer nano-array structure InGaAsP photocathode assembly with enhanced near-infrared response and preparation method thereof

Abstract

This invention proposes a thin-layer transmission In film with enhanced near-infrared response. 0.88 Ga 0.12 As 0.26 P 0.74 Photocathode assembly, the photocathode structure from bottom to top is In 0.88 Ga 0.12 As 0.26 P 0.74 Emitting layer, In 0.52 Al 0.48 As window layer, Si3N4 antireflective layer, and glass. In 0.52 Al 0.48 The As window layer comprises a planar layer and a nanostructure array, with Si3N4 dielectric filling the gaps between the nanostructures. The nanostructure array uses several periodically distributed cylindrical or square columnar structures. By adjusting the period, shape, size, and arrangement of the nanoarray structure, the overall absorption rate of the photocathode assembly at specific near-infrared wavelengths can be improved, thereby enhancing the transmission efficiency of the In photocathode. 0.88 Ga 0.12 As 0.26 P 0.74 The quantum efficiency of the photocathode at a specific near-infrared wavelength. This invention also presents an In... compatible with emerging micro / nano fabrication processes and traditional inversion processes. 0.88 Ga 0.12 As 0.26 P 0.74 Manufacturing process of photocathode components.

Description

Technical Field

[0001] This invention belongs to the field of near-infrared photoelectric detection technology, specifically a thin-layer nanoarray structure InGaAsP photocathode component with enhanced near-infrared response and its preparation method. Background Technology

[0002] Near-infrared photocathode devices are widely used in civilian and military fields, such as satellite remote sensing, astronomical exploration, precision weapon guidance, and surveillance and reconnaissance. Among these, infrared night vision devices play an irreplaceable role in military nighttime detection. In the absence of moonlight, the primary target for nighttime detection is sky light, but the energy in the visible light range of the sky light spectrum is one to two orders of magnitude lower than that in the near-infrared band. This places high demands on the near-infrared response capability and long-wavelength threshold of night vision devices. Early near-infrared photodetectors typically used Ag-O-Cs photocathodes, which had poor emission performance and short long-wavelength thresholds. Later, the emergence of GaAs photocathodes drew attention to the enormous potential of the tunable bandgap characteristics of III-V semiconductor materials in near-infrared photocathode research. With the maturation of NEA GaAs photocathodes and in-depth research on III-V semiconductor materials, near-infrared responsive photocathodes such as InGaAsP and InGaAs were invented. These near-infrared photocathodes extend the long-wavelength threshold and improve response capability. Compared to traditional NEAGaAs photocathodes, which have peak responses between 600nm and 750nm and threshold wavelengths not exceeding 930nm, resulting in low efficiency for night sky light detection, near-infrared photocathodes made from materials such as InGaAsP and InGaAs have long wavelength limits exceeding 1100nm, significantly improving long wavelength limits and effectively covering the entire night sky light spectrum, thus enhancing night vision performance.

[0003] InGaAsP, as a multi-element material, can have its band gap size controlled by adjusting its elemental composition, thereby extending the long-wavelength threshold of near-infrared photocathodes, making it an important near-infrared photocathode material. Considering that the lattice matching degree of the material affects the quality of the epitaxial growth of the photocathode material, which has a significant impact on its photoelectric emission performance, the fabrication selection of transmission-type InGaAsP photocathode components and the influence of In... 0.88 Ga 0.12 As 0.26 P 0.74 Lattice-matched InP was used as a substrate for epitaxial growth of the material. 0.52 Al 0.48As serves as both a corrosion barrier and a window layer. Furthermore, the limitations on the photoelectric performance of transmission-type InGaAsP photocathodes are also reflected in the contradictory influence of the emitter layer thickness on absorptivity and photoelectric emission performance: a thicker emitter layer allows for more complete light absorption, but results in a slower response speed, higher electron transport losses, and stronger lateral diffusion; conversely, a thinner emitter layer results in a faster response speed, lower transport losses, and weaker lateral diffusion, but at the expense of light absorption. Summary of the Invention

[0004] The purpose of this invention is to propose a thin-layer nanoarray structure InGaAsP photocathode component with enhanced near-infrared response.

[0005] The technical solution to achieve the purpose of this invention is: a near-infrared response enhanced thin-layer nanoarray structure InGaAsP photocathode component, comprising In... 0.88 Ga 0.12 As 0.26 P 0.74 Emitting layer, In 0.52 Al 0.48 As window layer, Si3N4 antireflection layer and glass, wherein the In 0.52 Al 0.48 As the window layer includes In 0.52 Al 0.48 As plane layer and set in In 0.52 Al 0.48 As the plane layer In 0.52 Al 0.48 As nanostructure array.

[0006] Preferably, the In 0.88 Ga 0.12 As 0.26 P 0.74 The emitter layer material is a p-type doped material with a doping concentration of 1×10⁻⁶. 18 ~1×10 19 cm -3 The thickness is 500–3000 nm.

[0007] Preferably, the In 0.52 Al 0.48 The As window layer is a p-type doped material with a doping concentration of 1×10⁻⁶. 18 ~1×10 19 cm -3 The thickness is 100–600 nm.

[0008] Preferably, In is filled with Si3N4 dielectric. 0.52 Al 0.48The voids in the As nanostructure array are filled, and a thickness of 100-400 nm is added on top of the nanostructure array to serve as a Si3N4 antireflection layer.

[0009] Preferably, the In 0.52 Al 0.48 The thickness of the As planar layer is 50–400 nm.

[0010] Preferably, the In 0.52 Al 0.48 As nanostructure arrays are periodically arranged in In 0.52 Al 0.48 As planar layer, cylindrical or square columnar structures are arranged with a period of 200–800 nm, a height of 50–500 nm, and a diameter of 100–600 nm; square columnar structures are arranged with a period of 200–800 nm, a height of 50–500 nm, and a width of 100–600 nm.

[0011] This invention proposes a nanoarray structure for transmission of In 0.88 Ga 0.12 As 0.26 P 0.74 The specific steps for fabricating a photocathode module are as follows:

[0012] Step 1: On an InP substrate, In atoms are epitaxially grown sequentially. 0.52 Al 0.48 As corrosion barrier layer, In 0.88 Ga 0.12 As 0.26 P 0.74 Emitting layer and In 0.52 Al 0.48 As the window layer, then PECVD deposition of Si3N4 dielectric;

[0013] Step 2: Apply photoresist evenly to the Si3N4 dielectric using spin coating.

[0014] Step 3: The Si3N4 dielectric layer is made to have properties similar to In through electron beam lithography or nanosphere self-assembly. 0.52 Al 0.48 As a mask with a consistent nanoarray structure pattern in the window layer;

[0015] Step 4: Using the Si3N4 dielectric layer as a mask, etch In using inductively coupled plasma etching (ICP-C) technology. 0.52 Al 0.48 As a window layer, a periodically distributed nanoarray structure is formed, and the Si3N4 dielectric layer is removed by selective etching with specific chemical reagents;

[0016] Step 5, once again in In 0.52Al 0.48 Si3N4 dielectric is deposited on the As window layer to completely fill the gaps in the nanoarray structure and form a Si3N4 antireflection layer above the structure.

[0017] Step 6: Thermally bond the glass to the Si3N4 antireflection layer;

[0018] Step 7: Immerse the sample in a mixed solution of HCl:H3PO4:CH3COOH to selectively etch and remove the InP substrate layer. Then immerse the sample in a mixed solution of HCl:H2O to remove the InP substrate. 0.52 Al 0.48 As a corrosion barrier layer;

[0019] Step 8: Activate the In using an ultra-high vacuum process. 0.88 Ga 0.12 As 0.26 P 0.74 A Cs / O or Cs / NF3 activation layer is formed on the surface of the emitter layer, ultimately yielding the In of this invention. 0.88 Ga 0.12 As 0.26 P 0.74 Cathode assembly.

[0020] Compared with the prior art, the present invention has the following significant advantages: 1) The material used in the present invention has lattice matching of each layer and good epitaxial growth quality, which ensures the photoelectric emission performance of the photocathode component; 2) The present invention adopts a nanoarray structure, which improves the absorption rate of the photocathode component for light of a specific wavelength in the near-infrared region, thereby improving the quantum efficiency of the photocathode at the specific wavelength in the near-infrared region; 3) The present invention can enhance the quantum efficiency of the photocathode at the target wavelength by changing the shape properties of the nanoarray structure, including the shape, arrangement period, linewidth, height and arrangement of the nanostructure; 4) The cutoff wavelength of the present invention is in the near-infrared band, which has high quantum efficiency for incident light with wavelengths near the near-infrared region and is not easily interfered with by incident light in irrelevant bands.

[0021] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a photocathode assembly.

[0023] Figure 2 It is a top view of a cylindrical nanostructure array arranged in a square.

[0024] Figure 3 It is a top view of a cylindrical nanostructure array arranged in a staggered pattern.

[0025] Figure 4 It is a top view of a square array of square columnar nanostructures.

[0026] Figure 5 It is a top view of a cylindrical nanostructure array arranged in a staggered pattern.

[0027] Figure 6 This is a comparison graph of the relationship between photocathode light absorptivity and incident light wavelength (linewidth 440nm).

[0028] Figure 7 This is a comparison graph of the relationship between photocathode light absorptivity and incident light wavelength (line width 360nm).

[0029] Figure 8 This is a comparison graph of the relationship between photocathode absorptivity and incident light wavelength (line width 240nm). Detailed Implementation

[0030] like Figure 1 As shown, a near-infrared response-enhanced thin-layer nanoarray InGaAsP photocathode assembly includes InGaAsP nanoarrays arranged from bottom to top. 0.88 Ga 0.12 As 0.26 P 0.74 Emitting layer, In 0.52 Al 0.48 As window layer, Si3N4 antireflection layer and glass, wherein the In 0.52 Al 0.48 As the window layer includes In 0.52 Al 0.48 As plane layer and set in In 0.52 Al 0.48 As the plane layer In 0.52 Al 0.48 As nanostructure array.

[0031] In a further embodiment, the In 0.88 Ga 0.12 As 0.26 P 0.74 The emitter layer material is a p-type doped material with a doping concentration of 1×10⁻⁶. 18 ~1×10 19 cm -3 The thickness is 500–3000 nm.

[0032] In a further embodiment, the In 0.52 Al 0.48 The As window layer is a p-type doped material with a doping concentration of 1×10⁻⁶. 18 ~1×10 19 cm -3 The thickness is 100–600 nm.

[0033] In a further embodiment, In is filled using Si3N4 dielectric. 0.52 Al 0.48 The voids in the As nanostructure array are filled, and a thickness of 100-400 nm is added on top of the nanostructure array to serve as a Si3N4 antireflection layer.

[0034] In a further embodiment, the thickness of the Si3N4 antireflection layer is (2k+1)λ / 4n, where n is the refractive index, k is a non-negative integer, and λ is the target wavelength.

[0035] In a further embodiment, the In 0.52 Al 0.48 The thickness of the As planar layer is 50–400 nm.

[0036] In a further embodiment, the In 0.52 Al 0.48 As nanostructure arrays are periodically arranged in In 0.52 Al 0.48 As planar layer, cylindrical or square columnar structures are arranged with a period of 200–800 nm, a height of 50–500 nm, and a diameter of 100–600 nm; square columnar structures are arranged with a period of 200–800 nm, a height of 50–500 nm, and a width of 100–600 nm.

[0037] In a further embodiment, the Si3N4 antireflection layer is made of Si3N4 material with a refractive index of 2.01 and a thickness of 130 nm.

[0038] This invention also provides a nanoarray structure In 0.88 Ga 0.12 As 0.26 P 0.74 The specific steps for fabricating a photocathode module are as follows:

[0039] Step 1: On an InP substrate, In atoms are epitaxially grown sequentially. 0.52 Al 0.48 As corrosion barrier layer, In 0.88 Ga 0.12 As 0.26 P 0.74 Emitting layer and In 0.52 Al 0.48 As the window layer, then PECVD deposition of Si3N4 dielectric;

[0040] Step 2: Apply photoresist evenly to the Si3N4 dielectric using spin coating.

[0041] Step 3: The Si3N4 dielectric layer is made to have properties similar to In through electron beam lithography or nanosphere self-assembly. 0.52 Al0.48 As a mask with a consistent nanoarray structure pattern in the window layer;

[0042] Step 4: Using the Si3N4 dielectric layer as a mask, etch In using inductively coupled plasma etching (ICP-C) technology. 0.52 Al 0.48 As a window layer, a periodically distributed nanoarray structure is formed, and the Si3N4 dielectric layer is removed by selective etching with specific chemical reagents;

[0043] Step 5, once again in In 0.52 Al 0.48 Si3N4 dielectric is epitaxially grown on the As window layer to completely fill the gaps in the nanoarray structure and grow a Si3N4 antireflection layer.

[0044] Step 6: Thermally bond the glass to the Si3N4 antireflection layer;

[0045] Step 7: Immerse the sample in a mixed solution of HCl:H3PO4:CH3COOH to selectively etch and remove the InP substrate layer. Then immerse the sample in a mixed solution of HCl:H2O to remove the InP substrate. 0.52 Al 0.48 As a corrosion barrier layer;

[0046] Step 8: Activate the In using an ultra-high vacuum process. 0.88 Ga 0.12 As 0.26 P 0.74 A Cs / O or Cs / NF3 activation layer is formed on the surface of the emitter layer, ultimately yielding the In of this invention. 0.88 Ga 0.12 As 0.26 P 0.74 Cathode assembly.

[0047] like Figure 6 , 7 , as shown in 8, In 0.52 Al 0.48 A nanoarray structure was constructed on the As window layer. The nanoarray structure improved the absorption rate of the photocathode module at wavelengths of 1075 nm, 1064 nm and 1050 nm, thereby helping to improve the quantum efficiency of the photocathode module at specific near-infrared wavelengths.

[0048] As one embodiment, the thickness of the Si3N4 antireflection layer is 130 nm; the Si3N4 filling medium is used to fill the gaps between the micro / nano structure array; the In having the micro / nano structure array 0.52 Al 0.48 The As window layer material is p-type doped with a doping concentration of 1×10⁻⁶. 19 cm -3The thickness is 200nm, with the height of the nanoarray structure being 150nm and the height of the planar layer being 50nm.

[0049] As one embodiment, the application of transmissive In 0.88 Ga 0.12 As 0.26 P 0.74 The fabrication method of the photoelectric cathode module yields a nanoarray structure that is a cylindrical or square columnar nanoarray structure with a periodic arrangement of squares, such as... Figure 2 , Figure 4 As shown, the nanoarray structure has a period P of 585 nm, a structure height of 150 nm, a planar layer height of 50 nm, and structure linewidths of: cylindrical linewidth a is 440 nm; square column linewidth a is 400 nm.

[0050] As one embodiment, the nanoarray structure is a cylindrical or square columnar nanoarray structure arranged in a 1 / 2 staggered pattern, such as... Figure 3 , Figure 5 As shown. The nanoarray structure has an arrangement period P of 585 nm. The row misalignment distance in the staggered periodic arrangement is equal to half of the arrangement period, i.e., P / 2 is 292.5 nm. The nanoarray structure height is 150 nm, the planar layer height is 50 nm, and the structure linewidth is: cylindrical linewidth a is 440 nm; square column linewidth a is 400 nm.

[0051] This invention is based on micro-nano optics theory. Micro-nano structures have the potential to improve the light absorption of photocathodes. Therefore, by introducing a micro-nano array structure into the window layer of a transmissive InGaAsP photocathode, the light absorption rate can be effectively improved without increasing the thickness of the emission layer, thereby improving the photoelectric emission performance of the thin-layer transmissive InGaAsP photocathode.

[0052] The near-infrared-response-enhanced thin-layer nanoarray InGaAsP photocathode of this invention improves the absorption rate at a specific near-infrared wavelength and is less susceptible to interference from incident light in irrelevant wavelength bands, making it applicable to various optoelectronic devices such as pulsed laser seed sources. Furthermore, this invention provides a complete fabrication process for photocathode components that is compatible with micro / nano fabrication techniques and traditional inversion processes, resulting in a transmissive InGaAsP nanoarray structure with good periodicity and complete morphology. 0.88 Ga 0.12 As 0.26 P 0.74 Photocathode assembly.

[0053] Example 1

[0054] In nanoarray structure fabricated using electron beam lithography 0.88 Ga 0.12 As 0.26 P 0.74Photocathode:

[0055] First, In was epitaxially grown sequentially on an intrinsic InP substrate using molecular beam epitaxy. 0.52 Al 0.48 As corrosion barrier layer, In 0.88 Ga 0.12 As 0.26 P 0.74 Emitting layer and In 0.52 Al 0.48 As the window layer, then PECVD is used to deposit Si3N4 dielectric.

[0056] The photoresist is uniformly coated onto the Si3N4 dielectric using spin coating. Electron beam exposure is performed first, followed by development with a developer. After the developer is removed, a photoresist layer with a circular array pattern having a period of 585 nm and a linewidth of 440 nm is obtained.

[0057] The photoresist layer pattern was etched onto the Si3N4 dielectric layer using reactive ion etching (RIE); In was then etched using inductively coupled plasma (ICP-POP) etching with the Si3N4 dielectric layer as a mask. 0.52 Al 0.48 As a window layer, a nanoarray structure with a periodic distribution of height of 150 nm is formed, and a planar layer with a height of 50 nm is formed.

[0058] The nanoarray structure still retains residual Si3N4 and photoresist. The residual photoresist is removed using methyl ethyl ketone (MEK), and the Si3N4 dielectric layer is removed by selective etching with specific chemical reagents. Then, Si3N4 material is deposited to a depth of 130 nm above the structure using plasma-enhanced chemical vapor deposition (PECVD), resulting in a Si3N4 antireflection layer and an In array structure with cylindrical or square columnar structures where the structural gaps are filled with Si3N4 dielectric. 0.52 Al 0.48 As the window layer.

[0059] The glass is thermally bonded to the Si3N4 antireflective layer.

[0060] The InP substrate layer was selectively etched away by immersing the sample in a mixed solution of HCl:H3PO4:CH3COOH. The InP substrate layer was then removed by immersing the sample in a mixed solution of HCl:H2O. 0.52 Al 0.48 As a corrosion barrier layer.

[0061] The component was placed in an ultra-high vacuum system for high-temperature purification. After cooling, a Cs / O or Cs / NF3 activation layer was attached to the clean emitter layer surface, ultimately producing an In nanoarray structure. 0.88 Ga 0.12 As 0.26 P 0.74 Photocathode assembly.

[0062] like Figure 6 As shown, when the cylindrical linewidth is 440nm, the cathode of the present invention exhibits significantly enhanced light absorption at 1075nm compared to the conventional cathode, thereby helping to improve the quantum efficiency of the photocathode assembly at a specific wavelength in the near-infrared region.

[0063] Example 2

[0064] Unlike Example 1, the nanoarray structure In 0.88 Ga 0.12 As 0.26 P 0.74 Nanostructure array In of photocathode module 0.52 Al 0.48 The nanoarray structure of the As window layer is cylindrical or square, and its nanoarray structure adopts a square or 1 / 2 staggered periodic arrangement with a period P of 500 nm. The structure height is 150 nm. In the window layer 0.52 Al 0.48 The As planar layer is 50nm; the structural linewidth is: 440nm for cylindrical lines and 400nm for square lines.

[0065] Example 3

[0066] Unlike Example 1, a photoresist with a circular array pattern having a period of 585 nm and linewidths of 360 nm and 240 nm was obtained by electron beam lithography or nanoimprint lithography. Using this patterned photoresist as a mask, the pattern was etched onto a Si3N4 dielectric layer using reactive ion etching. Finally, using the Si3N4 dielectric layer as a mask, the pattern was etched onto an In… 0.52 Al 0.48 On the As window layer, In with a cylindrical nanoarray structure is obtained. 0.52 Al 0.48 As a window layer. This In 0.52 Al 0.48 The cylindrical array of As window layer has a period of 585nm and a cylinder height of 150nm. The In in the window layer... 0.52 Al 0.48 The planar As layer is 50nm. When the cylindrical linewidth is 360nm, such as Figure 7 As shown, the cathode of this invention exhibits significantly enhanced light absorption at 1064 nm compared to conventional cathodes; when the cylindrical linewidth is 240 nm, as... Figure 8 As shown, the cathode of the present invention exhibits significantly enhanced light absorption at 1050 nm, which helps to improve the quantum efficiency of the cathode.

[0067] Example 4

[0068] In nanoarray structure prepared by self-assembly of nanospheres 0.88 Ga 0.12 As 0.26 P 0.74 Photocathode:

[0069] First, In was epitaxially grown sequentially on an intrinsic InP substrate using molecular beam epitaxy. 0.52 Al 0.48 As corrosion barrier layer, In 0.88 Ga 0.12 As 0.26 P 0.74 Emitting layer and In 0.52 Al 0.48 As the window layer.

[0070] Unlike Example 1, In with a nanoarray structure was prepared using a self-assembled nanosphere method. 0.52 Al 0.48 As a window layer. Monolayer SiO2 nanospheres are uniformly attached to In using a self-assembly method. 0.52 Al 0.48 The surface of the As window layer was etched, and the SiO2 nanospheres were etched using reactive ion etching technology to reduce the linewidth of the nanospheres to 240 nm, which is consistent with the linewidth of the target cylinder.

[0071] With In 0.52 Al 0.48 An array of SiO2 nanospheres on the surface of the As window layer is used as a mask layer, and In is etched using inductively coupled plasma etching technology. 0.52 Al 0.48 As a window layer, in In 0.52 Al 0.48 A nanoarray structure with a top SiO2 nanosphere mask layer, a height of 150 nm, and a planar layer with a height of 50 nm are formed on the As window layer.

[0072] The SiO2 nanosphere mask was removed by etching with a solution of 10% HF:40% NH4F diluted with 10 times the volume of deionized water at a volume ratio of 1:6, followed by rinsing with deionized water. This process yielded In... 0.52 Al 0.48 As nanostructure array, thus completing In 0.52 Al 0.48 As the window layer is constructed.

[0073] Si3N4 material was deposited 130 nm above the structure using plasma-enhanced chemical vapor deposition (PECVD) to obtain a Si3N4 antireflection layer and an In array structure with cylindrical or square columnar structures whose interstices were filled with Si3N4 dielectric. 0.52 Al0.48 As the window layer.

[0074] The glass is thermally bonded to the Si3N4 antireflective layer.

[0075] The InP substrate layer was selectively etched away by immersing the sample in a mixed solution of HCl:H3PO4:CH3COOH. The InP substrate layer was then removed by immersing the sample in a mixed solution of HCl:H2O. 0.52 Al 0.48 As a corrosion barrier layer.

[0076] The component was placed in an ultra-high vacuum system for high-temperature purification. After cooling, a Cs / O or Cs / NF3 activation layer was attached to the clean emitter layer surface, ultimately producing an In nanoarray structure. 0.88 Ga 0.12 As 0.26 P 0.74 Photocathode assembly.

[0077] This invention constructs a nanostructure array on the window layer of a photocathode module by using a fabrication process that is compatible with emerging micro-nano fabrication techniques and traditional inversion processes. By adjusting the morphology of the nanoarray structure, the absorption rate of the photocathode module at a specific wavelength can be improved, thereby ultimately improving the quantum efficiency of the photocathode module at that specific wavelength.

Claims

1. A thin-layer nano-array structure InGaAsP photocathode assembly with enhanced near-infrared response, characterized in that, comprises In 0.88 Ga 0.12 As 0.26 P 0.74 emitting layer (1), In 0.52 Al 0.48 As window layer (2), Si3N4 antireflection layer (3) and glass (4), wherein the In 0.52 Al 0.48 As window layer (2) comprises In 0.52 Al 0.48 As planar layer and In 0.52 Al 0.48 As planar layer comprises In 0.52 Al 0.48 As nanostructure array; The In 0.88 Ga 0.12 As 0.26 P 0.74 The material of the emission layer (1) is p-type doped material, the doping concentration is 1×10 18 ~1×10 19 cm -3 , the thickness is 500~3000nm, the In 0.52 Al 0.48 As window layer (2) is p-type doped material, the doping concentration is 1×10 18 ~1×10 19 cm -3 , the thickness is 100~600nm; In filled with Si3N4 medium 0.52 Al 0.48 As the gap in the nanostructure array of As, and the height of the nanoarray structure is set as the Si3N4 antireflection layer (3); The thickness of the Si3N4 anti-reflection layer is (2k+1)λ / 4n, wherein n is the refractive index, k is a non-negative integer, and λ is the target wavelength; The In 0.52 Al 0.48 As nanostructure array is a cylindrical or square column structure arranged periodically on an In 0.52 Al 0.48 The arrangement period of the cylindrical structure is 200-800 nm, the height of the cylindrical structure is 50-500 nm, and the diameter of the cylindrical structure is 100-600 nm; the arrangement period of the square column structure is 200-800 nm, the height of the square column structure is 50-500 nm, and the width of the square column structure is 100-600 nm.

2. The near-infrared response enhanced thin-layer nanorarray structure InGaAsP photocathode assembly of claim 1, wherein, The In 0.52 Al 0.48 As the plane layer thickness is 50-400 nm.

3. A method for preparing a near-infrared response enhanced thin-layer nanometer array structure InGaAsP photocathode assembly as claimed in claim 1 or 2, characterized in that, The specific steps are: Step 1, on InP substrate, In 0.52 Al 0.48 As etching stopper, In 0.88 Ga 0.12 As 0.26 P 0.74 emitting layer and In 0.52 Al 0.48 As window layer, then PECVD deposit Si3N4 dielectric; Step 2, uniformly cover the photoresist with Si3N4 medium by the spin coating method; Step 3, making the Si3N4 dielectric layer into a nano-array structure with the same pattern as the In 0.52 Al 0.48 As a mask with a nano-array structure pattern consistent with the window layer Step 4, using Si3N4 medium layer as mask, adopting inductive coupled plasma etching technology to etch In 0.52 Al 0.48 As the window layer, a periodic nano-array structure is formed, and the Si3N4 medium layer is removed by selective etching with a specific chemical reagent; Step 5, again in In 0.52 Al 0.48 As the Si3N4 medium is deposited on the window layer, the nano-array structure gap is completely filled, and the Si3N4 antireflection layer is formed by rising above the structure. Step 6, heat bonding the glass and the Si3N4 anti-reflection layer; Step 7, the sample is immersed in a mixed solution of HC1:H3PO4:CH3COOH to selectively etch and remove the InP substrate layer, and the sample is immersed in a mixed solution of HC1:H2O to remove In 0.52 Al 0.48 As an etching barrier Step 8, by ultra-high vacuum activation process, in In 0.88 Ga 0.12 As 0.26 P 0.74 A layer of Cs / O or Cs / NF3activation layer is formed on the surface of the emission layer, and finally the In 0.88 Ga 0.12 As 0.26 P 0.74 Cathode assembly is obtained.

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