Perovskite-based visible-near infrared photoelectric detector array and preparation method thereof

Abstract

The invention discloses a perovskite-based visible-near infrared photoelectric detector array and a preparation method thereof. The perovskite-based visible-near infrared photoelectric detector array comprises a substrate, an up-conversion particle / perovskite heterostructure and an electrode layer, wherein the up-conversion particle / perovskite heterostructure is arranged on the substrate; the heterostructure comprises a perovskite layer arranged on the substrate, the perovskite layer is composed of a plurality of perovskite micro-nanowires in one-dimensional linear arrangement, and an up-conversion material layer wraps the two transverse sides of the perovskite micro-nanowires from the side wall to form an up-conversion particle / perovskite structure; the absorption spectrum of the up-conversion material comprises a near-infrared band, and the emission spectrum is partially or completely matched with the absorption spectrum of the perovskite layer material. The detector array widens the absorption range of the perovskite to the near-infrared band under the condition that the inherent visible band detectability of the perovskite is not influenced, the up-conversion material absorbs near-infrared light and emits light in the visible band, the light can be effectively absorbed by the perovskite and generates electron hole pairs, and the photoelectric conversion efficiency is improved. Energy absorption and detection of the perovskite-based photoelectric detector from a visible spectrum section to a near infrared spectrum section are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano manufacturing and optoelectronic devices, and in particular to a perovskite-based visible-near infrared photodetector array and a preparation method thereof. Background Art

[0002] Broadening the capture range of optical bands is of great significance for various optoelectronic devices, such as solar cells and photodetectors. Traditional photodetectors, such as silicon, gallium arsenide, and gallium nitride-based photodetectors, can be used for photodetection, but the preparation process is cumbersome and its performance cannot meet the detection requirements in complex environments.

[0003] In recent years, as a new type of semiconductor optoelectronic material, metal halide perovskite has broad application prospects in various optoelectronic device fields due to its tunable band gap, long carrier diffusion length, high carrier mobility and solution preparation characteristics. Photodetectors based on 0D perovskite quantum dots, 1D perovskite wires, 2D perovskite materials, 3D perovskite polycrystalline films or single crystals have been widely reported. However, due to the inherent optical band gap of perovskites, single perovskite materials still face challenges in wide-spectrum detection, such as infrared detection (even if the light capture range can be broadened by band gap regulation, its detection range is difficult to exceed 800nm), which limits the application of perovskite devices in many fields.

[0004] Therefore, it is urgent to develop a preparation technology that can fully utilize the excellent performance of perovskite materials and broaden their detection band to achieve better optoelectronic performance. Summary of the invention

[0005] The present invention aims to provide a perovskite-based visible-near-infrared photodetector array and a preparation method thereof, which can broaden the detection wavelength of traditional perovskite photodetectors to the near-infrared band, and has a simple preparation process, is very sensitive to both the visible band and the near-infrared band, and can be prepared on a large area.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a perovskite-based visible-near-infrared photodetector array, comprising a substrate, an upconversion particle / perovskite heterostructure arranged on the substrate, and an electrode layer formed on the heterostructure; the upconversion particle / perovskite heterostructure comprises a perovskite layer, the perovskite layer is a plurality of one-dimensional linearly arranged perovskite micro-nanowires, an upconversion material layer is wrapped around the lateral sides of the perovskite micro-nanowires from the sidewalls to form a sidewall-wrapped upconversion particle / perovskite structure; the absorption spectrum of the upconversion material includes a near-infrared band, and the emission spectrum of the upconversion material partially or completely matches the absorption spectrum of the perovskite layer material.

[0007] The present invention can broaden the detection wavelength of traditional perovskite photodetectors to the near-infrared band. The preparation process of the perovskite-based visible-near-infrared photodetector array is simple, the response to both the visible band and the near-infrared band is very sensitive, and it can be prepared on a large area.

[0008] In one embodiment of the present invention, the substrate is a silicon dioxide sheet, a glass sheet, a quartz sheet, a PDMS film, a PET film, a PU film, a PI film or an aluminum oxide sheet.

[0009] In one embodiment of the present invention, the heterostructure is a structure formed by uniformly attaching a certain thickness of upconversion material to the regions on both sides of the perovskite layer; the electrode layer is oriented and arranged vertically and crosswise with the upconversion particles / perovskite heterostructure.

[0010] In one embodiment of the present invention, the electrode layer includes a plurality of one-dimensional linearly arranged electrodes, and the electrode layer is vertically cross-arranged with the heterostructure, and the upconversion material layer / perovskite layer between adjacent electrode layers forms a detection unit of the device.

[0011] In one embodiment of the present invention, the upconversion material layer / perovskite layer between adjacent electrodes is a detection unit of the device.

[0012] In one embodiment of the present invention, the perovskite layer is a one-dimensional linear structure array assembled by crystallization of perovskite materials, and the perovskite material is an inorganic / organic-inorganic hybrid perovskite material having an absorption spectrum in the visible region.

[0013] In one embodiment of the present invention, the inorganic / organic-inorganic hybrid perovskite material is selected from CsPbBr3, CsPbI2Br, CsPbI 2.2 Br 0.8 , MAPbBr3, MAPbI3, MAPbBr2I, for example, CsPbI 2.2 Br 0.8 .

[0014] In one embodiment of the present invention, the width of the perovskite micro-nanowire is 0.7-5 μm, preferably 0.755-2.51 μm, and more preferably 1-2 μm, for example, 1 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, 2.0 μm or any value within the range of any two of the above values.

[0015] Preferably, the height of the perovskite micro-nanowire is 0.1-3 μm, more preferably 0.1-1 μm, for example, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm or any value within the range of any two of the above values.

[0016] Preferably, the spacing between adjacent perovskite micro-nanowires is 5-40 μm, preferably 10-30 μm, for example, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm or any value within the range of any two of the above values.

[0017] In one embodiment of the present invention, the up-conversion material is a NaYF4-based fluorescent material that can absorb light in the near-infrared spectrum (800-1500nm), and has a particle size of 30-100nm; preferably 30-80nm, for example, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm or any value within the range of any two of the above points.

[0018] In one embodiment of the present invention, the up-conversion material has a regular or irregular shape, for example, a granular shape, a dumbbell shape, a polyhedron shape or a prism shape, and more preferably a granular shape.

[0019] In one embodiment of the present invention, the thickness of the up-conversion material layer is 100-1500 nm, preferably 100-800 nm, and more preferably 100-300 nm.

[0020] For example, 100nm, 120nm, 140nm, 160nm, 180nm, 200nm, 220nm, 240nm, 260nm, 280nm, 300nm or any value within the range of any two of the above points.

[0021] In one embodiment of the present invention, the electrode layer is a metal electrode having a one-dimensional linear structure, and the metal electrode is prepared by using a mask pattern transfer process such as thermal evaporation, magnetron sputtering or Lift-Off process.

[0022] Preferably, the metal electrode is selected from Au, Ag, Pt or Cu; for example, the metal electrode is a gold electrode with a one-dimensional linear structure.

[0023] Preferably, the width of the metal electrode is 20-200 μm, more preferably 20-150 μm, and further preferably 20-100 μm, for example, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or any value within the range of any two of the above values.

[0024] In one embodiment of the present invention, the spacing between adjacent metal electrodes is 5-100 μm, more preferably 5-30 μm, for example, 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 60 μm, 80 μm, 100 μm or any value within the range of any two of the above values.

[0025] Preferably, the thickness of the metal electrode is 20-500 nm, more preferably 30-300 nm, and further preferably 50-100 nm, for example, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm or any value within the range of any two of the above values.

[0026] In one embodiment of the present invention, the upconversion material layer / perovskite layer between adjacent electrodes is a detection unit of a photodetector array, and the length of the detection unit is the spacing between adjacent electrodes, preferably 5-100 μm, more preferably 5-30 μm.

[0027] In one embodiment of the present invention, the width of the detection unit is the width of the heterostructure formed by the upconversion material layer / perovskite layer, preferably 0.6-3 μm, more preferably 0.6-2.5 μm.

[0028] Preferably, the spacing between the detection units is the width of the metal electrodes.

[0029] According to another aspect of the present invention, there is also provided a method for preparing a perovskite-based visible-near infrared photodetector array, comprising the following steps:

[0030] 1) Injecting perovskite material ink onto the micro-column array template, placing a substrate on top of the perovskite material ink, and drying to form a perovskite array on the substrate; the micro-column array template, the perovskite material ink and the substrate form a sandwich structure.

[0031] 2) Injecting upconversion material ink along the channel orientation of the microcolumns and drying, the microcolumn array template induces and limits the upconversion material to in-situ lateral sidewall coating of the perovskite layer array, forming a one-dimensional array of sidewall-wrapped upconversion / perovskite heterostructures on the substrate.

[0032] 3) With the aid of a gate electrode mask, an electrode array arranged crosswise to the direction of step 1) is formed on the upconversion / perovskite array by using a mask pattern transfer process. The mask pattern transfer process is thermal evaporation, magnetron sputtering or lift-off process.

[0033] In one embodiment of the present invention, the micro-column array template includes a substrate and a plurality of wall-shaped micro-columns arranged on the substrate and distributed in an array.

[0034] In one embodiment of the present invention, the substrate is a silicon wafer, a silicon dioxide wafer, a glass wafer, a quartz wafer, an iron wafer, a copper wafer, a PDMS film, a PET film, a PU film, a PI film, an aluminum sheet or an aluminum oxide sheet.

[0035] In one embodiment of the present invention, the wall-shaped microcolumns are produced by photolithography.

[0036] Preferably, the wall width of the wall-type microcolumn is 2-5 μm and the height is 5-20 μm;

[0037] Preferably, the pitch of the microcolumn array is 10-60 μm, more preferably 20-40 μm, further preferably 20-30 μm, for example, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm.

[0038] In one embodiment of the present invention, the wetting angle of the substrate is 10°-60°, preferably 10°-40°, for example, 10°, 20°, 30°, 40°, 60°.

[0039] In one embodiment of the present invention, a weight of a certain mass may be arranged on the top of the substrate on the sandwich structure formed in step 1), and the sandwich structure and the weight together constitute a printing system. The weight may be a weight, an iron block, a glass sheet or a quartz sheet with a regular plane, preferably a weight, and the weight is preferably 1-20 g, more preferably 2 g-10 g.

[0040] In one embodiment of the present invention, the step 1) further comprises modifying a fluorosilane molecular layer on the surface of the micro-pillar array template as a hydrophobic layer.

[0041] Preferably, the fluorosilane is selected from one or more of perfluorooctyltriethoxysilane, perfluorodecyltrichlorosilane, perfluorooctyltrichlorosilane and perfluorodecyltrimethoxysilane.

[0042] Preferably, the perovskite material ink comprises a perovskite material and a solvent, the perovskite material has the definition as described above, and the solvent is an organic solvent, preferably an alcohol, an ester or a ketone.

[0043] For example, one or more of DMSO, DMF, γ-butyrolactone, acetonitrile, ethanol, and dioxane.

[0044] Preferably, the concentration of the perovskite material ink is 5-160 mg / mL, preferably 20-80 mg / mL, more preferably 20-60 mg / mL, for example, 20 mg / mL, 30 mg / mL, 40 mg / mL, 50 mg / mL, 60 mg / mL or any value within the range of any two of the above values.

[0045] Preferably, the perovskite material ink is CsPbI 2.2 Br 0.8 The material is dissolved in the solvent DMSO to form a solution with a concentration of 10-60 mg / mL, for example, 10 mg / mL, 20 mg / mL, 40 mg / mL, 60 mg / mL.

[0046] In one embodiment of the present invention, in the step 1), the perovskite material ink is dried under heating conditions, and the heating temperature is 60-120°C, preferably 90-110°C, for example, 90°C, 95°C, 100°C, 105°C, 110°C or any value within the range of any two of the above points.

[0047] In one embodiment of the present invention, the cross-section of the perovskite wires in the perovskite wire array formed after drying in step 1) is a "trapezoidal" structure, wherein the formation of the "trapezoidal" structure is related to the shrinkage behavior of the liquid during the printing process and the difference in wettability between the substrate and the microcolumn template. After the perovskite material forms a uniform liquid column under the induction of the microcolumn template, it will further shrink and supersaturate crystallize as the solvent evaporates. In this process, the line width is smaller in the area with a larger contact angle, and the line width is larger in the area with a smaller contact angle (the place in contact with the substrate is the bottom of the "trapezoidal" structure, the substrate has a smaller contact angle, and the bottom is wider; the place in contact with the microcolumn template is the top of the "trapezoidal" structure, the microcolumn template has a larger contact angle, and the top is narrower, thereby forming a trapezoidal structure with a narrow top and a wide bottom), and finally a perovskite wire array with a "trapezoidal" cross-section is formed.

[0048] Among them, the "trapezoidal" structure can be controlled by regulating the wettability of the substrate and template, the weight mass, and the concentration of the printing ink. The height and top width of the "trapezoidal" structure will affect the coating morphology of the subsequent secondary printing upconversion material. If the top width is too narrow, it will cause the subsequent secondary printing upconversion material to be coated on the top, further affecting the contact between the electrode and the perovskite material and the absorption of light by the perovskite material, affecting the device performance. The height of the "trapezoidal" structure can be adjusted in the range of 0.1-3μm, and the top width can be adjusted in the range of 0.7-5μm.

[0049] In one embodiment of the present invention, before injecting the upconversion material ink in step 2), the weight disposed on the top of the substrate in step 1) is first removed.

[0050] In one embodiment of the present invention, the orientation of the upconversion material ink injected in step 2) is consistent with the orientation of the micro-pillar array template in step 1).

[0051] In one embodiment of the present invention, the upconversion material ink includes an upconversion material and a dispersion solvent, wherein the upconversion material has the definition as described above, and the dispersion solvent is an organic solvent that is insoluble in perovskite, preferably benzene or alcohol, for example, toluene, chlorobenzene, o-dichlorobenzene or isopropanol.

[0052] In one embodiment of the present invention, the concentration of the upconversion material is 5-50 mg / mL, preferably 5-20 mg / mL, for example, 5 mg / mL, 8 mg / mL, 10 mg / mL, 12 mg / mL, 16 mg / mL, 18 mg / mL, 20 mg / mL or any value within the range of any two of the above values.

[0053] Preferably, the upconversion material ink is dried under heating conditions, and the preferred heating temperature is 90-140°C, and more preferably 110-130°C, for example, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C or any value within the range of any two of the above points.

[0054] In step 1), the micro-pillar array template is used to induce the shrinkage and segmentation of the perovskite solution to form a uniform liquid column with the same orientation as the micro-pillar template. During the drying process of the perovskite solution, the perovskite material crystallizes and assembles due to supersaturation to form a one-dimensional ordered linear structure on the substrate.

[0055] In step 2), the micro-pillar array template induces and restricts the upconversion material to perform in-situ lateral sidewall coating on the perovskite layer array, forming a one-dimensional array of sidewall-wrapped upconversion / perovskite heterostructures on the substrate.

[0056] Beneficial effects of the present invention:

[0057] 1) The present invention uses a template, perovskite material ink and a substrate to form a sandwich structure. The template induces the perovskite material ink to a designated area and dries and crystallizes to form a one-dimensional perovskite array with high orientation and crystallinity; the assembly system is kept stationary, and the upconversion material ink is injected inward along the template orientation to obtain a sidewall-coated upconversion / perovskite visible-near infrared photodetector array. The present invention has a simple preparation process, high precision, and can be prepared on a large area.

[0058] 2) The sidewall-wrapped upconversion / perovskite visible-near infrared photodetector array prepared in the present invention includes a substrate, a heterostructure formed by a perovskite layer and an upconversion material layer disposed on the substrate, and an electrode layer. The upconversion material is only wrapped on the lateral sides of the perovskite array, and the top is not covered with upconversion material. Without affecting the inherent visible band detection capability of perovskite, the absorption range of perovskite is broadened to the near-infrared band. The upconversion material (such as NaYF4@Yb, Er) absorbs near-infrared light and emits light in the visible band, which can be effectively absorbed by perovskite and generate electron-hole pairs, realizing the energy absorption and detection of perovskite-based photodetectors from the visible spectrum to the near-infrared spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a flow chart for preparing the sidewall-wrapped upconversion / perovskite photodetector in Example 1 of the present invention.

[0060] Figure 2 It is an electron microscope characterization image of the one-dimensional perovskite line array and the sidewall-wrapped upconversion particle / perovskite array obtained by printing in Example 1 of the present invention.

[0061] Figure 3 This is a real-time in-situ confocal microscope image of the two-step printing process in Example 1 of the present invention.

[0062] Figure 4 This is the spectral characterization of the perovskite material and the upconversion particle material in Example 1 of the present invention.

[0063] Figure 5 It is a schematic diagram of regulating the width and height of the one-dimensional perovskite array in Example 2 of the present invention.

[0064] Figure 6 It is a phase diagram and characterization diagram of the factors affecting the printing morphology of the upconversion particles in Example 2 of the present invention.

[0065] Figure 7 It is a characterization diagram of the fully wrapped type and sidewall wrapped type photoelectric detectors in Example 2 of the present invention and the corresponding visible-near infrared photoelectric response performance diagram.

[0066] Figure 8 It is an IV curve diagram of the sidewall encapsulated photodetector in Example 3 of the present invention at different wavelengths and different light intensities.

[0067] Fig. 9 It is a responsivity diagram calculated for the sidewall-wrapped photodetector in Example 3 of the present invention at different wavelengths and different light intensities.

[0068] Fig.10 Graphs showing the detectivity and external quantum efficiency of the sidewall-wrapped photodetector in Example 3 of the present invention calculated at different wavelengths. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be emphasized that the specific embodiments described herein are only used to better illustrate the present invention, are some embodiments of the present invention, not all embodiments, and are not used to limit the present invention. In addition, the technical features involved in the embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0070] Example 1

[0071] like Figure 1 As shown, the preparation of sidewall-wrapped upconversion / perovskite photodetector arrays is divided into the following three steps:

[0072] In the first step, a silicon substrate is provided, and wall-shaped microcolumns are made on the silicon substrate by photolithography to form a template; the wall width of the wall-shaped microcolumns is 2 μm, the height is 10 μm, and the spacing of the microcolumn array is 20 μm.

[0073] The perovskite solution is injected into the template, and a silica substrate is set on top of the perovskite solution. A weight of 5g is set on top of the silica substrate. The perovskite array is printed on the silica substrate, and the template induces the perovskite solution to shrink and crystallize to form a one-dimensional perovskite micrometer wire array. The perovskite solution is CsPbI 2.2 Br 0.8 The solution has a concentration of 20 mg / mL and the assembly temperature of the system is 110°C.

[0074] The width of the perovskite micro-nano wire is 1.6 μm, the height is 0.375 μm, and the spacing between adjacent perovskite micro-nano wires is 20 μm.

[0075] In the second step, after the first step of printing is completed, UCNPs ink is injected into the "sandwich" printing system in situ along the template orientation. Due to the lateral barrier of the perovskite array obtained by the first step of printing, the upconversion particles are only distributed on both sides of the perovskite array structure, forming a sidewall-wrapped upconversion particle / perovskite lateral heterogeneous array. In order to match the emission spectrum of the upconversion material with the absorption spectrum of the perovskite material, in order to achieve a better near-infrared response of the upconversion particle / perovskite photodetector. The upconversion particles are selected as NaYF4@Yb,Er nanoparticles, and the perovskite is selected as CsPbI 2.2 Br 0.8 .

[0076] The thickness of the up-conversion material layer is 200 nm, the particle size of the up-conversion particles is between 40-60 nm, the concentration is 10 mg / mL, and the assembly temperature of the system is 120°C.

[0077] The third step is to evaporate a 100nm thick Au electrode array on the surface of the sidewall-wrapped upconversion particle / perovskite lateral heterogeneous array with the aid of a mask to obtain a sidewall-wrapped upconversion particle / perovskite photodetector array. The Au electrode array is perpendicularly crossed with the upconversion / perovskite photodetector array. The width of the metal electrode Au is 50μm, and the spacing between adjacent metal Au electrodes is 5 microns. The upconversion material layer / perovskite layer between adjacent electrodes is the detection unit of the photodetector array, and the length of the detection unit is the spacing between adjacent electrodes. The width of the detection unit is 2μm.

[0078] The template, ink, and substrate together form a "sandwich" printing system. In the first printing process, the template induces the segmentation and contraction of the perovskite ink, forming a liquid column of uniform size. As the solvent evaporates, the perovskite ink is supersaturated and nucleates, crystallizes, and grows, resulting in an ordered one-dimensional perovskite array on the substrate, see Figure 2 As shown in a.

[0079] In the second printing process, under the induction effect of the template and the co-confinement effect of the template and the perovskite array obtained by the first printing step, the upconversion particles are only coated on both sides of the perovskite array structure, forming a sidewall-wrapped upconversion particle / perovskite lateral heterogeneous array, see Figure 2 As shown in b. The liquid bridge shrinkage behavior during the first printing process and the second printing process can be seen in Figure 3 shown.

[0080] from Figure 4 It can be seen that under the excitation of 980nm light, the emission spectrum of the upconversion material matches the peak position of the absorption spectrum of the perovskite material, indicating that the light excited by the upconversion particles can be fully absorbed by the perovskite material, revealing the energy transfer mechanism of the upconversion particle / perovskite photodetector to achieve near-infrared response.

[0081] Example 2

[0082] This embodiment is intended to illustrate the controlled preparation of different coating structures and the differences in light response performance of different coating structures.

[0083] The coating morphology of the upconversion particles on the perovskite array will affect the performance of the upconversion particles / perovskite visible-near infrared photodetector. In the first printing process, the width and height of the perovskite array will affect the heterostructure morphology of the upconversion particles / perovskite array. The width of the perovskite array can be adjusted by controlling the concentration of the perovskite ink, see Figure 5 As shown in a, the width of the perovskite array micro-nanowires ranges from 755nm to 2.51μm; the height of the perovskite array can be adjusted by controlling the pressure applied to the printing system, see Figure 5As shown in (b), the height of the perovskite array ranges from 245nm to 1.41μm.

[0084] When the pressure applied to the printing system is controlled at 0.2-1 KPa and the concentration of the perovskite ink is controlled at 20-80 mg / mL, the desired sidewall-wrapped upconversion particle / perovskite heterostructure is obtained, see Figure 6 shown.

[0085] In this embodiment, by simultaneously regulating the concentration of the perovskite ink and the pressure applied to the printing system, upconversion particles / perovskite heterostructures with different morphologies can be obtained, such as a fully wrapped heterostructure and a sidewall wrapped heterostructure, see Figure 7 As shown in a. Due to the covering of the upconversion particles in the fully encapsulated heterostructure, the light capture ability of the fully encapsulated heterostructure is reduced, thereby weakening its response ability to various bands. Figure 7 As shown in Figure b, under the excitation of visible light (450nm) and near-infrared light (980nm) of equal power, the photocurrent in the fully wrapped heterostructure is weaker than that in the sidewall wrapped heterostructure. The above results show that the upconversion particle / perovskite photodetector with sidewall wrapped structure has more advantages in response to light than the fully wrapped structure.

[0086] Example 3

[0087] This embodiment is intended to illustrate the light response performance of the sidewall-wrapped upconversion particle / perovskite visible-near infrared photodetector.

[0088] The performance of the sidewall-wrapped upconversion particle / perovskite lateral heterogeneous photodetector prepared in Example 1 was characterized using the semiconductor test platform Keithley 4200. Lasers of various wavelengths (450nm, 532nm, 650nm, 980nm) in the visible band and near-infrared band were vertically irradiated onto the surface of the photodetector, and the scanning voltage was 0-5V. The photocurrent-voltage (IV) curves of the photodetector under different wavelengths and different incident light intensities were tested, as shown in FIG. Figure 8 As shown, it can be seen that the upconversion particle / perovskite lateral heterostructure photodetector can broaden the absorption range of perovskite from the visible band to the near-infrared band, and has excellent dynamic photoresponse to light in the visible-near-infrared band.

[0089] Using the measured IV curves, the responsivity (R), detectivity (D*) and external quantum efficiency (EQE) of the sidewall-wrapped upconversion particle / perovskite lateral heterogeneous photodetector to different wavelengths are calculated, such as Fig. 9 and Fig.10As shown, under 5V bias, the maximum responsivities under 450nm, 532nm, 650nm and 980nm laser irradiation are 1084A / W, 604A / W, 102A / W and 150.5mA / W, respectively, the maximum detectivities are 3.34×1014Jones, 1.86×1014Jones, 3.15×1013Jones and 4.63×1010Jones, respectively, and the maximum external quantum efficiencies are 299414%, 141095%, 19586%, and 19.1%, respectively.

[0090] From the above results, it can be seen that the sidewall-wrapped upconversion particle / perovskite lateral heterogeneous visible-near-infrared photodetector has excellent photoelectric detection performance in both the visible light band and the near-infrared band.

[0091] The above describes the embodiments of the present invention in detail. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A perovskite-based visible-near infrared photodetector array, characterized in that: It includes a substrate, an upconversion particle / perovskite heterostructure disposed on the substrate, and an electrode layer formed on the heterostructure; The upconversion particle / perovskite heterostructure comprises a perovskite layer disposed on a substrate, wherein the perovskite layer is a plurality of one-dimensional linearly arranged perovskite micro-nanowires, and an upconversion material layer is wrapped around the lateral sides of the perovskite micro-nanowires from the sidewalls to form a sidewall-wrapped upconversion particle / perovskite structure; The absorption spectrum of the up-conversion material includes a near-infrared band, and the emission spectrum of the up-conversion material partially or completely matches the absorption spectrum of the perovskite layer material.

2. The perovskite-based visible-near infrared photodetector array according to claim 1, characterized in that: The electrode layer is oriented to be arranged in a cross arrangement with the perovskite layer and the up-conversion material layer. Preferably, the heterostructure is a structure formed by uniformly attaching a certain thickness of up-conversion material to regions on both sides of the perovskite layer.

3. The perovskite-based visible-near infrared photodetector array according to claim 1, characterized in that: The electrode layer comprises a plurality of one-dimensionally linearly arranged electrodes, and the electrode layer is vertically cross-arranged with the heterostructure, and the up-conversion material layer / perovskite layer between adjacent electrode layers forms a detection unit of the device.

4. The perovskite-based visible-near infrared photodetector array according to claim 1, characterized in that: The perovskite layer is a one-dimensional linear structure array assembled by crystallization of perovskite materials, and the perovskite material is an inorganic / organic-inorganic hybrid perovskite material with an absorption spectrum in the visible region. Preferably, the inorganic / organic-inorganic hybrid perovskite material is selected from CsPbBr3, CsPbI2Br, CsPbI 2.2 Br 0.8 , MAPbBr3, MAPbI3, MAPbBr2I, for example, CsPbI2.2Br 0.8 .

5. The perovskite-based visible-near infrared photodetector array according to claim 1, characterized in that: The width of the perovskite micro-nanowire is 0.7-5 μm, preferably 0.755-2.51 μm, and more preferably 1-2 μm, for example, 1 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, 2.0 μm or any value within the range of any two of the above values. Preferably, the height of the perovskite micro-nanowire is 0.1-3 μm, more preferably 0.245-1.41 μm, further preferably 0.1-1 μm, for example, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm or any value within the range of any two of the above values. Preferably, the spacing between adjacent perovskite micro-nanowires is 5-40 μm, preferably 10-30 μm, for example, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm or any value within the range of any two of the above values.

6. The perovskite-based visible-near infrared photodetector array according to claim 1, characterized in that: The up-conversion material is a NaYF4-based fluorescent material that can absorb light in the near-infrared spectrum of 800-1500nm, and has a particle size of 30-100nm; preferably 30-80nm, for example, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm or any value within the range of any two of the above points. Preferably, the up-conversion material has a regular or irregular shape, for example, a granular shape, a dumbbell shape, a polyhedron shape or a prism shape, more preferably a granular shape. Preferably, the thickness of the upconversion material layer is 100-1500nm, preferably 100-800nm, further preferably 100-300nm, for example, 100nm, 120nm, 140nm, 160nm, 180nm, 200nm, 220nm, 240nm, 260nm, 280nm, 300nm or any value within the range of any two of the above points. Preferably, the heterostructure formed by the perovskite layer and the up-conversion material layer is a lateral heterostructure formed by the up-conversion material only being uniformly wrapped on both lateral sides of the perovskite line.

7. The perovskite-based visible-near infrared photodetector array according to claim 1, characterized in that: The electrode layer is a metal electrode with a one-dimensional linear structure. Preferably, the metal electrode is prepared by using a mask pattern transfer process such as thermal evaporation, magnetron sputtering or Lift-Off process. Preferably, the metal electrode is selected from Au, Ag, Pt or Cu; for example, the metal electrode is a gold electrode with a one-dimensional linear structure. Preferably, the width of the metal electrode is 20-200 μm, more preferably 20-150 μm, and further preferably 20-100 μm, for example, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or any value within the range of any two of the above values. Preferably, the spacing between adjacent metal electrodes is 5-100 μm, more preferably 5-30 μm, for example, 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 60 μm, 80 μm, 100 μm or any value within the range of any two of the above values. Preferably, the thickness of the metal electrode is 20-500 nm, more preferably 30-300 nm, further preferably 50-100 nm. For example, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm or any value within the range of any two of the above points. Preferably, the upconversion material layer / perovskite layer between adjacent electrodes is a detection unit of a photodetector array, and the length of the detection unit is the spacing between adjacent metal electrodes, preferably 5-100 μm, more preferably 5-30 μm; the width of the detection unit is the width of the lateral heterostructure micro-nanowire formed by the upconversion material layer / perovskite layer, preferably 0.6-3 μm, further preferably 0.6-2.5 μm. Preferably, the spacing between the detection units is the width of the metal electrodes.

8. A method for preparing a perovskite-based visible-near infrared photodetector array according to any one of claims 1 to 7, characterized in that: The following steps are involved: 1) injecting perovskite material ink onto the micro-column array template, placing a substrate on top of the perovskite material ink, and drying to form a perovskite array on the substrate; 2) injecting upconversion material ink along the channel orientation of the microcolumns and drying, wherein the microcolumn array template induces and restricts the upconversion material to in-situ lateral sidewall coating of the perovskite layer array, thereby forming a one-dimensional array of sidewall-wrapped upconversion / perovskite heterostructures on the substrate; 3) With the assistance of a gate electrode mask, a mask pattern transfer process is used to form an electrode array on the upconversion / perovskite array that is arranged crosswise with the direction of step 1). Preferably, the micro-pillar array template in step 1) comprises a substrate and a plurality of wall-shaped micro-pillars arranged on the substrate in an array. The substrate is a silicon wafer, a silicon dioxide wafer, a glass wafer, a quartz wafer, an iron wafer, a copper wafer, a PDMS film, a PET film, a PU film, a PI film, an aluminum sheet or an aluminum oxide sheet. The wall-shaped microcolumns are made by photolithography and etching. Preferably, the wall width of the wall-type microcolumn is 2-5 μm and the height is 5-20 μm; Preferably, the pitch of the microcolumn array is 10-60 μm, more preferably 20-40 μm, further preferably 20-30 μm, for example, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm. Preferably, the substrate is a silicon wafer, a silicon dioxide wafer, a glass wafer, a quartz wafer or a PET film. The wetting angle of the substrate is 10°-60°, preferably 10°-40°, for example 10°, 20°, 30°, 40°, 60°. Preferably, the micro-pillar array template, the perovskite material ink and the substrate form a sandwich structure. Preferably, the sandwich structure formed in step 1) further comprises a weight of a certain mass arranged on the top of the base. The weight is an object with a regular plane such as a weight, an iron block, a glass sheet or a quartz sheet, preferably a weight, and the weight has a mass of 1-20g, preferably 2g-10g, such as 1g, 2g, 5g, 10g, 20g. The sandwich structure and the weight together constitute a printing system. Preferably, the mask pattern transfer process used in step 3) is thermal evaporation, magnetron sputtering or Lift-Off process.

9. The preparation method according to claim 8, characterized in that: The step 1) further includes modifying a fluorosilane molecular layer on the surface of the micro-pillar array template as a hydrophobic layer. Preferably, the fluorosilane is selected from one or more of perfluorooctyltriethoxysilane, perfluorodecyltrichlorosilane, perfluorooctyltrichlorosilane and perfluorodecyltrimethoxysilane. Preferably, the perovskite material ink is prepared from a perovskite material and a solvent, and the solvent is an organic solvent, preferably an alcohol, an ester or a ketone. For example, one or more of DMSO, DMF, γ-butyrolactone, acetonitrile, ethanol, and dioxane. Preferably, the concentration of the perovskite material ink is 5-160 mg / mL, preferably 20-80 mg / mL, and more preferably 20-60 mg / mL. For example, 20 mg / mL, 30 mg / mL, 40 mg / mL, 50 mg / mL, 60 mg / mL or any value within the range of any two of the above values. Preferably, the perovskite material ink is CsPbI 2.2 Br 0.8 The material is dissolved in the solvent DMSO to form a solution with a concentration of 10-60 mg / mL. Preferably, in the step 1), the perovskite material ink is dried under heating conditions, and the heating temperature is 60-120°C, preferably 90-110°C, for example, 90°C, 95°C, 100°C, 105°C, 110°C or any value within the range of any two of the above points. Preferably, the cross-section of the perovskite wires in the perovskite wire array formed after drying in step 1) is a "trapezoidal" structure; the height of the "trapezoidal" structure can be adjusted in the range of 0.1-3 μm, and the width of the narrow end ranges from 0.7-5 μm. Preferably, the orientation of the upconversion material ink injected in step 2) is consistent with the orientation of the micro-pillar array template in step 1). Preferably, before injecting the upconversion material ink in step 2), the weight disposed on the top of the substrate in step 1) is first removed.

10. The preparation method according to claim 8, characterized in that: The up-conversion material ink is formed by an up-conversion material and a dispersion solvent. The dispersion solvent is an organic solvent that does not dissolve perovskite, preferably a benzene or alcohol, such as toluene, chlorobenzene, o-dichlorobenzene or isopropyl alcohol. Preferably, the concentration of the upconversion material is 5-50 mg / mL, preferably 5-20 mg / mL. For example, 5 mg / mL, 8 mg / mL, 10 mg / mL, 12 mg / mL, 16 mg / mL, 18 mg / mL, 20 mg / mL or any value within the range of any two of the above points. Preferably, the upconversion material ink is dried under heating conditions, and the preferred heating temperature is 90-140°C, and more preferably 110-130°C, for example, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C or any value within the range of any two of the above points.

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