A single-point spectral-resolved photodetector based on perovskite semiconductor and its spectral measurement method

Abstract

This invention discloses a single-point spectral-resolved photodetector based on perovskite semiconductor and its spectral measurement method. By introducing a small-radius alkali metal halide salt into the perovskite active layer to reduce the ion migration activity energy in the semiconductor material, the redistribution of ions in the perovskite under an external field is promoted, causing the perovskite to exhibit a nonlinear response under different external fields, thus constructing a single-point spectral-resolved photodetector. The spectral measurement method includes the following steps: ① calibrating the device's responsivity to different wavelengths under different bias voltages V to obtain the responsivity calibration matrix R(V,λ); ② applying different bias voltage modulations to the device under an unknown light source to obtain the photocurrent matrix I(V) generated by the unknown light source under different bias voltages; ③ solving the linear equation system R(V,λ)x(λ)=I(V) to solve for the unknown spectrum x(λ). The above photodetector and measurement method enable single-point spectral detection, greatly simplifying the device structure of this type of spectrometer and facilitating device miniaturization and cost reduction.

Description

Technical Field

[0001] This invention relates to the field of spectral resolution detection, specifically to a single-point spectral resolution photodetector based on perovskite semiconductor and its spectral measurement method. Background Technology

[0002] Spectrometers are one of the most widely used characterization tools in scientific research and industrial production. Currently, portable or handheld spectroscopic analysis devices require the footprint of these spectroscopic analysis systems to be reduced to centimeters or even smaller. More extreme scales, such as millimeters or even sub-millimeters, hold promise for integrating spectroscopic analysis systems into smartphones or even miniature hyperspectral imaging systems. Since the 1990s, a series of traditional miniaturized spectrometers based on various working principles have emerged. Their principles can be roughly divided into three categories: (1) Dispersive spectrometers represented by prisms, which disperse composite light into monochromatic light and perform spectral analysis by spatially separated detectors; (2) Using narrow-bandpass filters to transmit specific spectral components to different detectors; (3) Fourier transform spectrometers based on Fourier transform. Early traditional spectrometers were all based on these three principles, and their miniaturized design was similar to a scaled-down benchtop spectrometer, i.e., an interferometer using diffractive optics or microelectromechanical systems. The presence of mechanical structures inevitably affects the development of on-chip spectrometers. In addition, spectral resolution also depends heavily on the number of detectors, which also poses a challenge to further reducing the footprint of spectrometers.

[0003] Over the past two decades, with the rapid development of computing technology, a new mode of spectral analysis has emerged. Its principle is based on approximating or reconstructing the unknown incident spectrum from pre-coded calibration information from a set of detectors. In other words, unknown information is reconstructed by solving an inverse problem, where reconstruction refers to solving a set of linear equations. Currently, computational spectrometers employ two main strategies: spectral spatial mapping and detector-dependent spectral response. However, regardless of the strategy, the optical resolution of computational spectrometers remains limited by the number of detectors (the number of linear equations). For example, CN113029338A discloses a spectral-resolved detector assembly that achieves detection of different wavelengths by setting multiple detector structures made of different perovskite materials on a substrate. It is evident that improving resolution inevitably requires increasing the number of detectors, which further limits the reduction of the spectrometer footprint. Therefore, developing an in-situ tunable detector is essential.

[0004] Organic-inorganic halide perovskites possess large optical absorption constants, good band gaps, large exciton binding energies, and excellent photoresponse capabilities, making them promising candidate materials for photodetectors. Their photoconductive gain increases significantly, exceeding 100%, under different external electric fields. Furthermore, even under the same external electric field excitation, the optical gain produced by incident light of different wavelengths varies due to the migration of intrinsic ions under external electric field excitation. When recombination light interacts with the perovskite, the location of photogenerated carriers is asymmetrical; short-wavelength incident light only generates photogenerated carriers near the surface, while long-wavelength infrared light generates photogenerated carriers distributed throughout the entire film. Moreover, under external electric field excitation, most photogenerated carriers are generated in the barrier region, as this region bears the majority of the voltage drop. Under the excitation of an external electric field, the migration of intrinsic ions in perovskite along the direction of the electric field causes the directional movement of the barrier region, which gradually transitions from a short-wavelength excitation position to a long-wavelength excitation position. This results in different optical gains for incident light of different wavelengths, thus realizing that the responsivity function changes with the external electric field. However, relying on the migration of intrinsic halide ions in perovskite will cause the following two problems: (1) the migration of halide ions with larger radii is not obvious under the excitation of an external electric field; (2) the migration of intrinsic ions will destroy the lattice structure of perovskite and thus affect the photoelectric properties. Summary of the Invention

[0005] The technical problem to be solved by this invention is to improve the photoresponse rate as a function of the external electric field and to reduce the stability problems caused by intrinsic ion redistribution to the semiconductor itself. This invention provides a single-point spectral-resolved photodetector based on perovskite semiconductor and its spectral measurement method.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] The first aspect of the present invention provides a single-point spectral-resolved photodetector based on perovskite semiconductor, characterized in that a small-radius alkali metal halide salt is introduced into the perovskite material of the photodetector, wherein the alkali metal in the small-radius alkali metal halide salt is lithium, sodium, potassium or rubidium.

[0008] Furthermore, the small-radius alkali metal halide salt is preferably LiCl and / or NaCl.

[0009] Furthermore, the molar ratio of the small-radius alkali metal halide salt to the perovskite material is 0.01-0.1:1.

[0010] If the doping amount of small-radius alkali metal halide salts in the perovskite layer is higher than 10%, it will cause the perovskite to form a large amount of lead iodide, affecting the crystallinity of the perovskite and thus affecting its photoelectric properties.

[0011] Furthermore, the photodetector is composed of, from bottom to top, a transparent conductive substrate, an electron transport layer, a perovskite active layer, a hole transport layer, and a top electrode.

[0012] Furthermore, the material of the transparent conductive substrate is selected from ITO, FTO, and AZO.

[0013] Furthermore, the material of the electron transport layer is selected from SnO2, ZnO, and TiO2.

[0014] Furthermore, the thickness of the electron transport layer is preferably 50-100 nm.

[0015] Furthermore, the material of the perovskite active layer is selected from FAPbI3, MAPbI3, and Cs. x FA y MA 1-x-y Pb(I z Br 1-z One of 3, where FA is formamidin, MA is methylamine, and 0 <x,y,z<1,x+y<1。

[0016] Furthermore, the thickness of the perovskite active layer is preferably 200-500 nm.

[0017] Furthermore, the material of the hole transport layer is selected from Spiro-OMeTAD and PTAA.

[0018] Furthermore, the thickness of the hole transport layer is preferably 100-300 nm.

[0019] Furthermore, the top electrode is made of gold or silver.

[0020] Furthermore, the method for fabricating the photodetector includes the following steps:

[0021] S1: Perform surface hydrophilic treatment on the transparent conductive substrate;

[0022] S2: The electron extraction material colloid is mixed with a solvent to obtain an electron extraction layer precursor solution, which is then coated onto the substrate surface treated by S1 to obtain an electron transport layer.

[0023] S3: Dissolve the perovskite component material in a solvent to obtain a perovskite precursor solution, then add an alkali metal halide salt, heat and stir to obtain a mixed solution, and coat the obtained mixed solution onto the electron transport layer to obtain a perovskite active layer.

[0024] S4: Spin-coat the hole transport material onto the perovskite active layer to obtain the hole transport layer;

[0025] S5: Finally, metal electrode material is deposited on the surface of the hole transport layer to prepare the photodetector.

[0026] Furthermore, in S1, the surface hydrophilic treatment specifically involves placing the transparent conductive substrate in a surface ozone cleaning machine for 5-30 minutes.

[0027] Furthermore, in S2, the volume ratio of the electron extraction material colloid to the solvent is preferably 1:1-6; the solvent includes, but is not limited to, ultrapure water and chlorobenzene.

[0028] Furthermore, in S2, the electron extraction layer precursor solution is coated onto the substrate surface by spin coating;

[0029] Furthermore, in S3, the temperature for heating and stirring is 70-100℃, and the stirring time is 15-20 minutes.

[0030] Further, in S4, the hole transport material is first mixed with 4-tert-butylpyridine and Li-TFSI, and then the resulting mixed solution is spin-coated onto the perovskite layer; the spin-coating speed is 1000-3000 rpm and the spin-coating time is 20-40 s.

[0031] A second aspect of the present invention provides a spectral measurement method for the single-point spectral-resolution photodetector described in the first aspect, specifically comprising the following steps:

[0032] (1) Apply different bias voltages between the top electrode and the transparent conductive substrate to calibrate the responsivity of the device to different wavelengths λ under different bias voltages V, and obtain the responsivity calibration matrix R(V,λ);

[0033] (2) Under the light source to be tested, different bias voltage modulations are applied to the photodetector to obtain the photocurrent matrix I(V) generated by the unknown light source under different bias voltages;

[0034] (3) Construct a linear system of equations R(V,λ)x(λ)=I(V) and solve for the unknown spectrum x(λ).

[0035] Furthermore, in steps (1) and (2), the applied bias voltage is 0. <V≤0.7V。

[0036] At a voltage of 0–0.7V, ion migration can be induced without damaging the perovskite crystal structure. However, if the voltage is too high, irreversible damage to the perovskite lattice will occur.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1. This invention introduces small-radius alkali metal halide salts into perovskite materials, using small-radius exogenous ions to replace the migration of intrinsic halide ions in perovskite, thereby reducing the impact of intrinsic ion migration and redistribution on semiconductor stability. In addition, the doping of small-radius alkali metal halide salts reduces the activation energy of ion migration, thereby improving the change of photoresponse rate with the external electric field, and further reducing the correlation of perovskite response functions under different external fields, thus satisfying the conditions for in-situ voltage-optical response modulation.

[0039] 2. The single-point spectral-resolved photodetector based on perovskite semiconductor prepared by this invention does not contain any optical or mechanical structures. It can realize the spectral line resolution of unknown light through a single detector site. Compared with the prior art, which realizes the detection of different wavelengths by setting multiple detection structures made of different perovskite materials on the substrate, the single-point spectral-resolved photodetector provided by this invention greatly simplifies the structure of the device, breaks the theoretical trade-off between spectral resolution and pixel resolution of reconstructed spectrometers, and is conducive to the miniaturization of the device and the control of costs. Attached Figure Description

[0040] Figure 1 XRPD comparison images of perovskite films with different LiCl doping concentrations;

[0041] Figure 2 a is the curve showing the change in ion migration activation energy of perovskite films doped with 5% LiCl and undoped;

[0042] Figure 2 b is a graph showing the electronic conductivity of 5% LiCl-doped and undoped perovskite films as a function of time.

[0043] Figure 3 a is a schematic diagram of the structure of the single-point spectral resolution detector prepared in Example 2;

[0044] Figure 3 b is a scanning electron microscope image of the cross-section of the single-point spectral resolution detector prepared in Example 2;

[0045] Figure 4 a is a graph showing the change in responsivity of the single-point spectral resolution detector prepared in Example 2 as a function of the external electric field;

[0046] Figure 4 b is a graph showing the change of the external quantum efficiency of the single-point spectral resolution detector prepared in Example 2 as a function of the external electric field;

[0047] Figure 4 c represents the light detectivity of the single-point spectral resolution detector prepared in Example 2 under conditions without an external electric field.

[0048] Figure 4d represents the light detectivity of the single-point spectral resolution detector prepared in Example 2 under different external electric fields;

[0049] Figure 4 e represents the scintillation noise of the single-point spectral resolution detector prepared in Example 2 under different voltages as a function of frequency;

[0050] Figure 4 f is the shot noise curve of the single-point spectral resolution detector prepared in Example 2 as a function of the applied voltage value;

[0051] Figure 5 a is a spectral reconstruction image of semiconductor lasers of different wavelengths obtained by the single-point spectral resolution detector prepared in Example 2;

[0052] Figure 5 b is the spectral reconstruction of the LED by the single-point spectral resolution detector prepared in Example 2;

[0053] Figure 5 c is the spectral reconstruction of a halogen lamp by the single-point spectral resolution detector prepared in Example 2. Detailed Implementation

[0054] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0056] Example 1: Study on the effect of LiCl doping amount on perovskite crystallinity

[0057] Different amounts of LiCl (doping amount is a mass percentage relative to the perovskite material, 0%, 1%, 3%, 5%, 10%, 15%) were doped into a perovskite precursor solution. Undoped or differently doped perovskite films were prepared by spin-coating on the same electron transport layer. The effect of LiCl doping amount on the crystallinity and electrical properties of perovskite was observed. The preparation methods of the perovskite films with different doping amounts are shown below:

[0058] (1) The ITO substrate was placed in a UV-ozone environment for 20 minutes to make the substrate surface hydrophilic;

[0059] (2) Mix SnO2 colloid with ultrapure water at a ratio of 1:6, and stir on a cold table for 15 min to obtain SnO2 aqueous solution;

[0060] (3) 50 μL of SnO2 aqueous solution was applied to the substrate, and then the substrate was spin-coated at 5000 rpm for 20 s. The substrate was then placed on a hot plate at 150 °C for 10 min to anneal and remove the residual aqueous solution, thus preparing the electron transport layer.

[0061] (4) Dissolve 1.15M PbI2, 1.1M FAI, 0.2M PbBr and 0.2M MABr in 0.96mL of DMF solvent to obtain a perovskite precursor solution. Then add 40μL of CsI / DMSO solution (1.5M) and LiCl solution to the perovskite precursor solution and stir at 70℃ for 20min.

[0062] (5) The prepared perovskite precursor solution was spin-coated onto an ITO substrate coated with SnO2 using a two-step spin-coating method: first, the spin speed was 1000 rpm with an acceleration of 400 rpm / s, and then the speed was 4000 rpm with an acceleration of 1000 rpm / s. 25 s before the end of the spin-coating, 100 μL of chlorobenzene was added as an antisolvent. Finally, the spin-coated perovskite film was annealed at 100 °C for 10 min.

[0063] XRPD characterization was performed on perovskites with different doping concentrations, and the characterization results are as follows: Figure 1 As shown, doping a small amount of LiCl into perovskite materials fills the gaps in the perovskite crystal structure and has little effect on its crystal structure. When the doping amount increases to more than 10%, diffraction peaks that can be attributed to PbI2 appear on the XRPD pattern, indicating that a large amount of lead iodide is formed in the highly doped perovskite material. It is speculated that the excessive accumulation of LiCl causes the partial collapse of the perovskite crystal structure, thereby affecting the overall photoelectric properties of the material.

[0064] Comparing the ion migration activation energies of perovskite films before and after LiCl doping, such as Figure 2 As shown in Figure a, compared to the undoped sample, the ion migration activation energy of the perovskite film doped with 5% LiCl decreased from 0.5 eV to 0.32 EV, and the change in conductivity is as follows: Figure 2 As shown in b, the ionic conductivity of the doped sample is higher than that of the undoped sample. The changes in ion migration activation energy and conductivity indicate that the introduced exogenous alkali metal ions are more likely to migrate under the influence of an external field.

[0065] Example 2: Fabrication of a single-point spectral resolution detector

[0066] A method for fabricating a single-point spectral resolution detector based on perovskite semiconductor is as follows:

[0067] (1) The ITO substrate was placed in a UV-ozone environment for 20 minutes to make the substrate surface hydrophilic;

[0068] (2) Mix SnO2 colloid with ultrapure water at a ratio of 1:6, and stir on a cold table for 15 min to obtain SnO2 aqueous solution;

[0069] (3) 50 μL of SnO2 aqueous solution was applied to the substrate, and then the substrate was spin-coated at 5000 rpm for 20 s. The substrate was then placed on a hot plate at 150 °C for 10 min to anneal and remove the residual aqueous solution, thus preparing the electron transport layer.

[0070] (4) Dissolve 1.15M PbI2, 1.1M FAI, 0.2M PbBr and 0.2M MABr in 0.96mL of DMF solvent to obtain a perovskite precursor solution. Then add 40μL of CsI / DMSO solution (1.5M) and 20μL of LiCl / DMSO solution (1M) to the perovskite precursor solution and stir at 70℃ for 20min.

[0071] (5) The prepared perovskite precursor solution was spin-coated onto an ITO substrate coated with SnO2 using a two-step spin-coating method: first, the spin speed was 1000 rpm with an acceleration of 400 rpm / s, and then the speed was 4000 rpm with an acceleration of 1000 rpm / s. 25 s before the end of the spin-coating, 100 μL of chlorobenzene was added as an antisolvent. The spin-coated perovskite film was annealed at 100 °C for 10 min.

[0072] (6) Dissolve 72.3 mg Spiro-OMeTAD in 1 mL of chlorobenzene, then add 29 μL of 4-tert-butylpyridine and 18 μL of Li-TFSI solution (dissolved in acetonitrile, concentration 520 mg / mL), and stir for 3 hours to obtain Spiro-OMeTAD solution. Take 50 μL of the Spiro-OMeTAD solution after stirring and spin-coat it onto a perovskite film at 2000 rpm to prepare a hole transport layer;

[0073] (7) The single-point spectral resolution detector is prepared by evaporating metal electrode material on the surface of the hole transport layer.

[0074] A schematic diagram of the structure of the single-point spectral resolution detector prepared above is shown in the figure. Figure 3 As shown in Figure a, the cross-sectional morphology of the detector was observed using a scanning electron microscope, such as... Figure 3 As shown in b.

[0075] Example 3

[0076] The single-point spectral resolution detector prepared in this embodiment differs from the detector prepared in Example 2 only in its electron transport layer; all other aspects are the same. The preparation of the electron transport layer in this embodiment is shown below:

[0077] Add 1 mL of chlorobenzene to 20 mg of PCBM and stir for 3 h to obtain a PCBM solution; apply 50 μL of PCBM solution to an FTO substrate, then spin-coat at 5000 rpm for 20 s, and then anneal on a hot plate at 100 °C for 10 min.

[0078] Example 4

[0079] The single-point spectral resolution detector prepared in this embodiment differs from the detector prepared in Example 2 in that its perovskite layer is different, but all other aspects are the same. The preparation of the perovskite layer in this embodiment is shown below:

[0080] 1.15M PbI2, 1.1M MAI, 0.2M PbBr and 0.2M MABr were dissolved in 0.96 mL of DMSO solvent to prepare a perovskite precursor solution. Then, 40 μL of CsI / DMSO solution (1.5M) and 20 μL of LiCl / DMSO solution (1M) were added to the perovskite precursor solution and stirred at 70 °C for 20 min to obtain a mixed solution.

[0081] The above mixed solution was spin-coated onto an ITO substrate coated with SnO2 using a two-step spin-coating method: first at a spin speed of 1000 rpm and an acceleration of 400 rpm / s, and then at 4000 rpm and an acceleration of 1000 rpm / s. 25 s before the end of spin-coating, 100 μL of chlorobenzene was added as an antisolvent. The spin-coated perovskite film was annealed at 100 °C for 10 min to obtain the perovskite layer.

[0082] Example 5

[0083] The single-point spectral resolution detector prepared in this embodiment differs from the detector prepared in Example 2 in that its perovskite layer is different, but all other aspects are the same. The preparation of the perovskite layer in this embodiment is shown below:

[0084] A perovskite precursor solution was prepared by dissolving 0.06 M CsI, 0.97 M FAI, 0.97 M PbI2, 0.17 M MABr, and 0.17 M PbBr2 in 1 mL of a DMSO / DMF (volume ratio 4:1) mixed solvent. Then, 20 μL of LiCl / DMSO solution (1 M) was added and the mixture was stirred at 60 °C for 2 h to obtain a mixed solution.

[0085] The above mixed solution was spin-coated onto an ITO substrate coated with SnO2 using a two-step spin-coating method. The spin-coating speeds were 1000 rpm and 4000 rpm, and the spin-coating times were 10 s and 30 s, respectively. Ten s before the end of the second spin-coating step, 20 μL of chlorobenzene was added dropwise onto the film as an antisolvent. The spin-coated perovskite film was then annealed at 100 °C for 60 min to obtain the perovskite layer.

[0086] Performance characterization of single-point spectral resolution detectors

[0087] The responsivity, external quantum efficiency, detectivity, and noise current of the single-point spectral resolution detector prepared in Example 2 were studied as a function of the external electric field.

[0088] Figure 4 Figures a and 4b show the changes in responsivity and external quantum efficiency of the single-point spectral resolution detector with the external electric field. As can be seen from the figure, the increase in responsivity and external quantum efficiency with increasing voltage is greater in the high-wavelength band (600-750nm) than in the low-wavelength band (350-600nm), indicating that the responsivity and external quantum efficiency of the detector prepared in this invention exhibit nonlinear gain with increasing voltage. Figure 4 c and 4d are the detector detectivity of the detector for light under the influence of no external electric field and different external electric field intensities, respectively (detectivity reflects the lowest signal intensity that the detector can detect from noise). Under different conditions, the detector detectivity of light generally increases with the increase of wavelength. Among them, when a voltage is applied, the detector detectivity for light of the same wavelength increases with the increase of voltage. Figure 4 e represents the curve of the detector's flicker noise changing with frequency under different voltages. Figure 4 f represents the curve of the detector's shot noise changing with the applied voltage. As shown in the figure, when the applied voltage is 0.7V, its noise current is only 2μm. The above characterization results demonstrate that the detector prepared in this invention has high responsivity and detectivity.

[0089] Spectral testing using a single-point spectral resolution detector

[0090] The method for performing spectral measurements using a single-point spectral resolution detector is as follows:

[0091] (1) Calibration of the responsivity matrix: The voltage sweep mode of 4200-SCS was used to calibrate the responsivity of the perovskite detector prepared in Example 1 for different wavelengths, and the responsivity matrix R(V,λ) was obtained. The specific experimental operation was as follows: a halogen lamp light source was used as the calibration light source, the single voltage application time was 0.1s, and the idle time was 5s.

[0092] The wavelength range is 350-750nm, the wavelength sampling interval is 10nm, the voltage sampling interval under a single wavelength is 0.001V, and the voltage sampling range is 0-0.7V.

[0093] (2) Measurement of unknown spectrum: The sampling matrix I(V) is obtained by sampling the photocurrent generated by the unknown incident light source, where the voltage sampling interval is 0.001V and the voltage range is set to 0-0.7V; the spectrum of the unknown incident light source is calculated by iteratively solving min║Rx-I║2 using the non-negative least squares method.

[0094] The spectra of semiconductor lasers, LEDs, and halogen lamps at different wavelengths were tested using the above method. The reconstructed spectra were compared with the original spectra, and the results are as follows: Figure 5 As shown, Figure 5 Figures a and c show the comparison between the spectra of semiconductor lasers, LEDs, and halogen lamps of different wavelengths and the reconstructed spectra, respectively. As can be seen from the figures, the reconstructed spectra after testing different light sources can be well superimposed on the original spectra, which confirms that the single-point spectral resolution detector prepared in this invention can realize the spectral measurement of unknown light sources and has high testing accuracy.

[0095] The embodiments described above are merely preferred embodiments for fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A single-point spectral-resolution photodetector based on perovskite semiconductor, characterized in that, The photodetector is composed of a transparent conductive substrate, an electron transport layer, a perovskite active layer, a hole transport layer, and a top electrode, from bottom to top. A small-radius alkali metal halide salt is introduced into the perovskite material of the photodetector, and the alkali metal in the small-radius alkali metal halide salt is lithium, sodium, potassium, or rubidium. The molar ratio of the small-radius alkali metal halide salt to the perovskite material is 0.01-0.1:1; The preparation of the perovskite layer includes the following steps: dissolving the perovskite component material in a solvent to obtain a perovskite precursor solution, then adding an alkali metal halide salt, heating and stirring to obtain a mixed solution, and coating the above mixed solution onto an electron transport layer to obtain a perovskite active layer. The thickness of the perovskite active layer is 200-500 nm.

2. The single-point spectral-resolution photodetector based on perovskite semiconductor according to claim 1, characterized in that, The small-radius alkali metal halide salt is LiCl and / or NaCl.

3. A single-point spectral-resolution photodetector based on perovskite semiconductor according to claim 1, characterized in that, The transparent conductive substrate is made of a material selected from ITO, FTO, and AZO; the electron transport layer is made of a material selected from SnO2, ZnO, and TiO2; the hole transport layer is made of a material selected from Spiro-OMeTAD and PTAA; and the top electrode is made of gold or silver.

4. A single-point spectral-resolution photodetector based on perovskite semiconductor as described in claim 1, characterized in that, The material of the perovskite active layer is selected from FAPbI3, MAPbI3, and Cs. x FA y MA 1-x-y Pb(I z Br 1-z One of 3, where FA is formamidin, MA is methylamine, and 0 <x,y,z<1,x+y<1。 5. A single-point spectral-resolution photodetector based on perovskite semiconductor as described in claim 1, characterized in that, The method for fabricating the photodetector includes the following steps: S1: Perform surface hydrophilic treatment on the transparent conductive substrate; S2: The electron extraction material colloid is mixed with a solvent to obtain an electron extraction layer precursor solution, which is then coated onto the substrate surface treated by S1 to obtain an electron transport layer. S3: Dissolve the perovskite component material in a solvent to obtain a perovskite precursor solution, then add an alkali metal halide salt, heat and stir to obtain a mixed solution, and coat the above mixed solution onto the electron transport layer to obtain a perovskite active layer. S4: Spin-coat the hole transport material onto the perovskite active layer to obtain the hole transport layer; S5: Finally, metal electrode material is deposited on the surface of the hole transport layer to prepare the photodetector.

6. A single-point spectral-resolution photodetector based on perovskite semiconductor as described in claim 5, characterized in that, In S3, the temperature for heating and stirring is 70-100 ℃, and the stirring time is 15-20 min.

7. A spectral measurement method based on the single-point spectral-resolution photodetector according to any one of claims 1 to 6, characterized in that, The spectral measurement method includes the following steps: (1) Apply different bias voltages between the top electrode and the transparent conductive substrate, and calibrate the device under different bias voltages. V Below are different wavelengths λ The response rate is obtained by measuring the response rate and obtaining the response rate calibration matrix R( V , λ ); (2) Under the light source under test, different bias voltage modulations are applied to the photodetector to obtain the photocurrent matrix I( ) generated by the light source under test under different bias voltages. V ); (3) Construct a system of linear equations R( V , λ ) x ( λ )=I( V Solve for the spectrum of the light source under test. x ( λ ).

8. The spectral measurement method according to claim 7, characterized in that, In steps (1) and (2), the applied bias voltage is 0. <V≤0.7 V。

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