All-inorganic narrow-band perovskite photodetector and preparation method thereof

Abstract

The application discloses a kind of all-inorganic narrow-band perovskite photoelectric detector and preparation method thereof, wherein, preparation method includes: selecting glass substrate with FTO electrode cathode, and etching groove on the back of glass substrate;Perovskite filter layer is prepared in groove using sintering process on FTO electrode cathode;Perovskite light absorption layer is prepared on TiO2 electron transport layer;Wherein, perovskite light absorption layer and perovskite filter layer are prepared using different all-inorganic perovskite material;Electrode anode is deposited on perovskite light absorption layer, and all-inorganic narrow-band perovskite photoelectric detector is obtained.The method effectively filters a part of light using perovskite filter layer, so that the absorption wavelength range of perovskite light absorption layer is narrowed, and the detection accuracy of photoelectric detector in a specific narrow band is improved;And perovskite filter layer prepared using sintering process has better quality and uniformity, and component adjustment is more free.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device technology, specifically relating to an all-inorganic narrowband perovskite photodetector and its fabrication method. Background Technology

[0002] A photodetector is a device that converts incident light signals (such as ultraviolet, visible, or infrared light) into electrical signals. It is crucial in industrial and scientific applications such as imaging, optical communication, environmental monitoring, and biosensing. Perovskite photodetectors primarily utilize perovskite-type metal halide semiconductors as light-absorbing materials. Metal halide perovskites offer significant advantages, possessing numerous excellent optical and electrical properties, including tunable bandgap, long carrier diffusion length, high mobility, and low defect density.

[0003] Among them, all-inorganic materials are excellent light-absorbing materials for photodetectors due to their superior phase stability. Based on the tunable bandgap of perovskites, some studies have achieved the identification of specific narrow wavelength bands by preparing different perovskite materials on both sides of a glass substrate using a solution method.

[0004] However, perovskite filter layers prepared by traditional solution methods are insufficient for completely filtering incident light, resulting in incomplete filtering and causing severe interference in the detection of small signals in photodetectors based on them. Furthermore, traditional techniques for adjusting the bandgap of perovskites involve composition engineering, but the bandgap adjustment achieved through composition engineering is relatively large, making it difficult to achieve changes in the light absorption range of just a few nanometers. Summary of the Invention

[0005] To address the problems of incomplete filtering, narrow process windows, and difficulty in precisely adjusting the light absorption range in existing narrowband photodetectors, this invention provides an all-inorganic narrowband perovskite photodetector and its fabrication method. The technical problem solved by this invention is achieved through the following technical solution:

[0006] A first aspect of the present invention provides a method for fabricating an all-inorganic narrowband perovskite photodetector, comprising:

[0007] A glass substrate with an FTO electrode cathode is selected, and a groove is etched on the back side of the glass substrate;

[0008] A TiO2 electron transport layer is prepared on the FTO electrode cathode;

[0009] A perovskite filter layer was prepared in the groove using a sintering process.

[0010] A perovskite light-absorbing layer is prepared on the TiO2 electron transport layer; wherein the perovskite light-absorbing layer and the perovskite filter layer are prepared using different all-inorganic perovskite materials;

[0011] An electrode anode is deposited on the perovskite light-absorbing layer to obtain an all-inorganic narrowband perovskite photodetector.

[0012] In one embodiment of the present invention, the groove is rectangular, and the distance between each side of the groove and each side of the glass substrate is 2mm.

[0013] In one embodiment of the present invention, the material of the perovskite filter layer includes CsPbBr3.

[0014] In one embodiment of the present invention, the perovskite filter layer is prepared in the groove using a sintering process, comprising:

[0015] CsBr solid powder and PbBr2 solid powder were mixed to obtain a mixed powder;

[0016] The mixed powder is filled into the groove, and the entire sample is placed on a heating plate to melt the mixed powder into liquid CsPbBr3; then the liquid CsPbBr3 is cooled and crystallized, and finally slowly cooled to room temperature, thereby forming a CsPbBr3 perovskite filter layer in the groove.

[0017] In one embodiment of the present invention, the perovskite filter layer is prepared in the groove using a sintering process, comprising:

[0018] CsBr solid powder and PbBr2 solid powder were dissolved in dimethyl sulfoxide solution, and CsPbBr3 powder was obtained by co-deposition and drying.

[0019] The CsPbBr3 powder is filled into the groove, and the entire sample is placed on a heating plate to melt the mixed powder into liquid CsPbBr3. The liquid CsPbBr3 is then cooled and crystallized, and finally slowly cooled to room temperature to form a CsPbBr3 perovskite filter layer in the groove.

[0020] In one embodiment of the present invention, the mass ratio of the CsBr solid powder to the PbBr2 solid powder is 0.58.

[0021] In one embodiment of the present invention, the material of the perovskite light-absorbing layer includes Cs2PbI2Cl2.

[0022] In one embodiment of the present invention, a perovskite light-absorbing layer is prepared on the TiO2 electron transport layer, comprising:

[0023] PbI2 solid was dissolved in dimethyl sulfoxide solution and stirred until PbI2 was completely dissolved to obtain PbI2 solution; CsCl solid was dissolved in methanol solution and stirred until CsCl was completely dissolved to obtain CsCl solution;

[0024] In an N2 atmosphere, the PbI2 solution is spin-coated onto the TiO2 electron transport layer and then annealed to form a PbI2 layer on the TiO2 electron transport layer.

[0025] The sample was immersed in CsCl solution to soak the PbI2 layer, and then the sample was annealed to form a Cs2PbI2Cl2 perovskite light absorption layer on the TiO2 electron transport layer.

[0026] In one embodiment of the present invention, the nanostructure of Cs2PbI2Cl2 can be changed by adjusting the concentration of the CsCl solution, thereby forming a Cs2PbI2Cl2 perovskite light-absorbing layer including at least one nanostructure such as nanowires, nanosheets, or thin films.

[0027] A second aspect of the present invention provides an all-inorganic narrowband perovskite photodetector, which is prepared according to the method described in the above embodiments, and includes a glass substrate, an FTO electrode cathode, a TiO2 electron transport layer, a perovskite light absorption layer and an electrode anode arranged sequentially from bottom to top.

[0028] The glass substrate has a groove on its back side, and a perovskite filter layer is disposed in the groove; and the perovskite light absorption layer and the perovskite filter layer are made of different inorganic perovskite materials.

[0029] The beneficial effects of this invention are:

[0030] 1. The preparation method provided by this invention is based on the different absorption spectral wavelength ranges of the perovskite filter layer material and the perovskite light absorption layer material. Different combinations of all-inorganic perovskite materials are selected, and the perovskite filter layer is prepared by sintering process. This can more effectively filter out a part of the incident light, narrowing the absorption wavelength range of the perovskite light absorption layer and improving the detection accuracy of the photodetector in a specific narrow band. Moreover, the perovskite filter layer prepared by sintering process has higher quality, better uniformity, and more flexible composition adjustment, and can achieve changes in the light absorption range of several nanometers.

[0031] 2. The preparation method provided by this invention allows for the selection of different combinations of all-inorganic perovskite materials according to the requirements of the detection band. When the light-absorbing layer uses Cs2PbI2Cl2, the concentration and soaking time of the CsCl soaking solution can be adjusted to achieve controllable adjustment of the Cs2PbI2Cl2 nanostructure, thereby achieving micro-adjustment of the light absorption range and avoiding the core problem of difficulty in precisely adjusting the light absorption range in component engineering. Furthermore, the thickness of the filter layer can be adjusted by etching the thickness of the grooves, thereby achieving adjustment of the filtering effect.

[0032] 3. The preparation method provided by the present invention can use CsPbBr3 powder obtained directly by co-precipitation method when preparing CsPbBr3 perovskite filter layer, so that the filter layer is more dense and uniform and the filtering effect is better.

[0033] 4. The preparation method provided by this invention takes into account both the requirements of preparation process and cost, and shows strong application potential. It has the advantages of low cost, easy implementation and easy reproducibility.

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0035] Figure 1 This is a schematic flowchart of a method for fabricating an all-inorganic narrowband perovskite photodetector provided in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the process for fabricating an all-inorganic narrowband perovskite photodetector provided in an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of an all-inorganic narrowband perovskite photodetector provided in an embodiment of the present invention;

[0038] Explanation of reference numerals in the attached figures:

[0039] 1-Glass substrate, 2-FTO electrode cathode, 3-TiO2 electron transport layer, 4-Perovskite light absorption layer, 5-Electrode anode, 6-Perovskite filter layer. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0041] Example 1

[0042] Please see Figure 1 , Figure 1 This is a schematic flowchart of a method for fabricating an all-inorganic narrowband perovskite photodetector according to an embodiment of the present invention. The method includes:

[0043] Step 1: Select a glass substrate with an FTO electrode cathode and etch grooves on the back side of the glass substrate.

[0044] Specifically, in this embodiment, a glass substrate with an FTO electrode cathode is selected, denoted as Glass / FTO substrate. The glass substrate with the FTO electrode cathode can be soda-lime glass. The thickness of the FTO electrode cathode can be 100 nm to 120 nm, and the thickness of the glass substrate excluding the FTO electrode cathode can be 1.5 mm to 2.5 mm.

[0045] Understandably, pretreatment is required before etching the glass substrate, specifically including:

[0046] First, the glass substrate with the FTO electrode cathode was sequentially immersed in Decon-90 aqueous solution, deionized water, acetone, and anhydrous ethanol for ultrasonic cleaning for 15 minutes.

[0047] Among them, Decon 90 aqueous solution is Decon-90 alkaline cleaning solution, which is a surface-active cleaner / radioactive contaminant purifier. It can be used for various applications in laboratories, medical and specialized industries. It is provided in the form of a non-viscous concentrated liquid, which can be diluted with water. It is biodegradable, completely rinseable and non-flammable.

[0048] Then, the cleaned glass substrate with the FTO electrode cathode is placed in UV-OZONE for 15 to 30 minutes.

[0049] Finally, grooves are etched on the back side of the pretreated glass substrate.

[0050] Optionally, the groove is rectangular in shape, with each side approximately 2 mm from the edge of the glass substrate and a thickness of approximately 250 μm. Understandably, the thickness of the groove can be adjusted according to the required filtering performance.

[0051] Step 2: Prepare a TiO2 electron transport layer on the FTO electrode cathode.

[0052] Specifically, TiO2 (titanium dioxide) sol is spin-coated onto the FTO electrode cathode and then annealed to form a TiO2 electron transport layer on the FTO electrode cathode.

[0053] Optionally, as one implementation, in this embodiment, 80 μL of TiO2 sol is spin-coated onto a UV-OZONE-treated glass substrate with an FTO electrode cathode in air at a rotation speed of 3000 rpm for 30 s using a spin coater. The TiO2-coated glass substrate with the FTO electrode cathode is then placed in a muffle furnace and annealed at 500°C in air for 1 h to prepare a TiO2 electron transport layer with a thickness of 50 nm to 80 nm, resulting in a Glass / FTO / TiO2 substrate.

[0054] Step 3: Prepare a perovskite filter layer in the groove using a sintering process.

[0055] In this embodiment, an all-inorganic perovskite material can be selected to prepare the perovskite filter layer. For example, CsPbBr3 perovskite filter layer can be prepared using CsBr and PbBr2 materials; CsPbI2Br perovskite filter layer can also be prepared using CsBr and PbI2 materials.

[0056] Preferably, in this embodiment, CsPbBr3 perovskite filter layer is prepared using CsBr solid powder and PbBr2 solid powder. Therefore, step 3 specifically includes:

[0057] 31) Mix CsBr solid powder and PbBr2 solid powder to obtain mixed powder.

[0058] Optionally, in this embodiment, the mass ratio of CsBr solid powder to PbBr2 solid powder is 0.58 when preparing the mixed powder.

[0059] Specifically, 213 mg of CsBr and 367 mg of PbBr2 solid powder were mixed to obtain a mixed powder.

[0060] Understandably, the total amount of mixed powder can be adjusted according to the thickness of the groove, but the mass ratio remains constant.

[0061] 32) Fill the groove with the mixed powder and place the entire sample on a heating plate to melt the mixed powder into liquid CsPbBr3; then cool and crystallize the liquid CsPbBr3, and finally slowly cool it to room temperature to form a CsPbBr3 perovskite filter layer in the groove.

[0062] Specifically, the mixed powder is filled into the groove, and the substrate is placed on a heating plate heated to 575°C. The solid powder begins to melt, and the liquid CsPbBr3 is cooled to 560°C at a variable cooling rate to crystallize. Then, it is slowly cooled to room temperature (cooling rate of 1 K·min). -1 ), thus obtaining the CsPbBr3 / Glass / FTO / TiO2 substrate.

[0063] The perovskite filter layer prepared by the sintering process of this invention has higher quality and better uniformity. Moreover, it does not need to consider the solubility of halide precursors, and the composition can be adjusted more freely, enabling changes in the light absorption range of several nanometers.

[0064] Furthermore, based on different filtering performance requirements, the thickness of the CsPbBr3 perovskite filter layer can be adjusted by changing the thickness of the etched grooves, without the need for thickness control through secondary polishing or other technical methods.

[0065] Step 4: Prepare a perovskite light-absorbing layer on the TiO2 electron transport layer.

[0066] Specifically, in this embodiment, the perovskite light absorption layer and the perovskite filter layer are prepared using different all-inorganic perovskite materials.

[0067] Optionally, in this embodiment, the perovskite filter layer is CsPbBr3, and the perovskite light absorption layer can be Cs2PbI2Cl2. Step 4 then specifically includes:

[0068] 41) Dissolve solid PbI2 in dimethyl sulfoxide solution and stir until PbI2 is completely dissolved to obtain PbI2 solution; dissolve solid CsCl in methanol solution and stir until CsCl is completely dissolved to obtain CsCl solution.

[0069] First, 461 mg of solid PbI2 was dissolved in 1 mL of dimethyl sulfoxide solution and stirred at 80 °C until completely dissolved to obtain a PbI2 solution.

[0070] Then, 8 mg of CsCl solid was dissolved in 1 mL of methanol solution and stirred at room temperature until all CsCl was dissolved to obtain a CsCl solution.

[0071] 42) In an N2 atmosphere, a PbI2 solution was spin-coated onto the TiO2 electron transport layer and then annealed to form a PbI2 layer on the TiO2 electron transport layer.

[0072] Specifically, the CsPbBr3 / Glass / FTO / TiO2 substrate obtained in step 3 was placed in an N2 atmosphere, and 80 μL of PbI2 solution was spin-coated onto the CsPbBr3 / Glass / FTO / TiO2 substrate at 2000 rpm for 30 s. Then, it was placed on a hot plate and annealed at 200 °C for 10 min to obtain the CsPbBr3 / Glass / FTO / TiO2 / PbI2 substrate.

[0073] 43) The above sample was placed sideways in CsCl solution to soak the PbI2 layer, and then the sample was annealed to form a Cs2PbI2Cl2 perovskite light absorption layer on the TiO2 electron transport layer.

[0074] Specifically, the PbI2 side of the CsPbBr3 / Glass / FTO / TiO2 / PbI2 substrate obtained in step 42) is immersed in CsCl solution for 30 seconds, and then placed on a hot plate and annealed at 250°C for 10 minutes to obtain the CsPbBr3 / Glass / FTO / TiO2 / Cs2PbI2Cl2 substrate.

[0075] It should be noted that in this embodiment, the nanostructure of Cs2PbI2Cl2 can be changed by adjusting the concentration of the CsCl solution, thereby forming a Cs2PbI2Cl2 perovskite light-absorbing layer including at least one nanostructure such as nanowires, nanosheets, or thin films.

[0076] The Cs2PbI2Cl2 layer formed here is a hybrid structure of nanosheets and thin films.

[0077] The preparation method provided by this invention allows for the selection of different combinations of all-inorganic perovskite materials according to the requirements of the detection band; when the light-absorbing layer is Cs2PbI2Cl2, the Cs2PbI2Cl2 nanostructure can be controllably adjusted by adjusting the concentration of the CsCl soaking solution and the soaking time.

[0078] Step 5: Deposit an electrode anode on the perovskite light-absorbing layer to obtain an all-inorganic narrowband perovskite photodetector.

[0079] Specifically, at room temperature, conductive carbon paste was deposited on the CsPbIBr2 perovskite light-absorbing layer using screen printing, and then annealed on a hot plate at 120°C for 15 min to obtain a thickness of 5 μm to 10 μm and an area of ​​0.085 cm². 2 The carbon electrode anode was used to complete the fabrication of the all-inorganic narrowband perovskite photodetector.

[0080] The preparation method provided by this invention is based on the different absorption spectral wavelength ranges of the perovskite filter layer material and the perovskite light absorption layer material. Different combinations of all-inorganic perovskite materials are selected, and a perovskite filter layer is prepared using a sintering process. This method can more effectively filter out a portion of the incident light, narrowing the absorption wavelength range of the perovskite light absorption layer and improving the detection accuracy of the photodetector in a specific narrow band. Furthermore, this method simultaneously addresses the requirements of fabrication process and cost, demonstrating strong application potential and possessing the advantages of low cost, ease of implementation, and reproducibility.

[0081] Example 2

[0082] The following describes another embodiment of the fabrication method of the all-inorganic narrowband perovskite photodetector proposed in this invention.

[0083] Please see Figure 2 , Figure 2 This is a schematic diagram of the process for fabricating an all-inorganic narrowband perovskite photodetector according to an embodiment of the present invention. The fabrication method of this all-inorganic narrowband perovskite photodetector includes the following steps:

[0084] Step 1: Select a glass substrate with an FTO electrode cathode and etch grooves on the back side of the glass substrate.

[0085] Specifically, such as Figure 2 As shown in Figure (a), a rectangular groove is etched on the back side of a glass substrate with an FTO electrode cathode. The distance between each side of the groove and each side of the glass substrate is about 2 mm, and the thickness is about 250 μm.

[0086] It is understood that pretreatment is required before etching the glass substrate, including cleaning and UV-OZONE treatment. For details, please refer to Example 1 above.

[0087] Step 2: Prepare a TiO2 electron transport layer on the FTO electrode cathode.

[0088] 80 μL of TiO2 (titanium dioxide) sol was spin-coated onto a UV-OZONE-treated glass substrate with an FTO electrode cathode in air at 3000 rpm for 30 s using a spin coater. The TiO2-coated glass substrate with the FTO electrode cathode was then placed in a muffle furnace and annealed at 500 °C in air for 1 h to prepare a TiO2 electron transport layer with a thickness of 50 nm to 80 nm, resulting in a Glass / FTO / TiO2 substrate. Figure 2 As shown in Figure (b) of the document.

[0089] Step 3: Prepare a CsPbI2Br perovskite filter layer in the groove using a sintering process.

[0090] 3a) CsBr solid powder and PbBr2 solid powder were dissolved in dimethyl sulfoxide solution, and CsPbBr3 powder was obtained by co-deposition and drying.

[0091] Specifically, 213 mg of CsBr and 367 mg of PbBr2 solid powder by mass ratio were dissolved in 1 ml of dimethyl sulfoxide solution, and CsPbBr3 powder was obtained by co-deposition and drying.

[0092] 3b) Fill the groove with CsPbBr3 powder and place the entire sample on a heating plate to melt the mixed powder into liquid CsPbBr3; then cool the liquid CsPbBr3 to crystallize, and finally slowly cool it to room temperature to form a CsPbBr3 perovskite filter layer in the groove.

[0093] Specifically, CsPbBr3 powder was used to fill the grooves, and the substrate was placed on a heating plate heated to 575°C. The solid powder began to melt, and the liquid CsPbBr3 was cooled to 560°C at a variable cooling rate to crystallize. Then, it was slowly cooled to room temperature (cooling rate of 1 K·min). -1 ), to obtain a CsPbBr3 / Glass / FTO / TiO2 substrate, such as Figure 2 As shown in Figure (c).

[0094] In this embodiment, CsPbBr3 powder obtained directly by co-precipitation is used when preparing the CsPbBr3 perovskite filter layer, which makes the prepared filter layer more dense and uniform and has a better filtering effect.

[0095] Step 4: Prepare a Cs2PbI2Cl2 perovskite light absorption layer on the TiO2 electron transport layer.

[0096] Take 461 mg of solid PbI2 and dissolve it in 1 mL of dimethyl sulfoxide solution. Stir at 80 °C until completely dissolved to obtain PbI2 solution.

[0097] The CsPbBr3 / Glass / FTO / TiO2 substrate was placed in an N2 atmosphere, and 80 μL of PbI2 solution was spin-coated onto the CsPbBr3 / Glass / FTO / TiO2 substrate at 2000 rpm for 30 s. The substrate was then placed on a hot plate and annealed at 200 °C for 10 min to obtain the CsPbBr3 / Glass / FTO / TiO2 / PbI2 substrate.

[0098] Take 6 mg of CsCl solid and dissolve it in 1 mL of methanol solution. Stir at room temperature until all CsCl is dissolved to obtain a CsCl solution.

[0099] The PbI2 side of the CsPbBr3 / Glass / FTO / TiO2 / PbI2 substrate was immersed in CsCl solution for 30 s, and then annealed on a hot plate at 250 °C for 10 min to obtain the CsPbBr3 / Glass / FTO / TiO2 / Cs2PbI2Cl2 substrate. Figure 2 As shown in Figure (d), this Cs₂PbI₂Cl₂ layer is a hybrid structure of nanowires and nanosheets.

[0100] Step 5: Deposit an electrode anode on the perovskite light-absorbing layer to obtain an all-inorganic narrowband perovskite photodetector.

[0101] Conductive carbon paste was deposited on a Cs₂PbI₂Cl₂ perovskite light-absorbing layer using screen printing at room temperature, and then annealed at 120°C for 15 min to obtain a thickness of 5 μm–10 μm and an area of ​​0.085 cm². 2 The carbon electrode anode, such as Figure 2 As shown in Figure (e).

[0102] This completes the fabrication of the all-inorganic narrowband perovskite photodetector.

[0103] Example 3

[0104] Based on Embodiments 1 and 2 above, this embodiment provides an all-inorganic narrowband perovskite photodetector. Please refer to... Figure 3 , Figure 3 This is a schematic diagram of the structure of an all-inorganic narrowband perovskite photodetector provided in an embodiment of the present invention. The all-inorganic narrowband perovskite photodetector includes:

[0105] The following components are arranged from bottom to top: glass substrate 1, FTO electrode cathode 2, TiO2 electron transport layer 3, perovskite light absorption layer 4, and electrode anode 5.

[0106] The glass substrate 1 has a groove on its back side, and a perovskite filter layer 6 is provided in the groove; and the perovskite light absorption layer 4 and the perovskite filter layer 6 are made of different inorganic perovskite materials.

[0107] In this embodiment, the glass substrate 1 has a thickness of 1.5 mm to 2.5 mm, the FTO cathode 2 has a thickness of 100 nm to 120 nm, and the TiO2 electron transport layer 3 has a thickness of 50 nm to 80 nm. The anode 5 can be a carbon electrode with a thickness of 5 μm to 10 μm and an area of ​​0.085 cm². 2 .

[0108] Optionally, the material of the perovskite light-absorbing layer 4 can be CsPbBr3, with a thickness of 250μm to 300μm; the material of the perovskite filter layer 6 can be Cs2PbI2Cl2, with a thickness of 450nm to 550nm.

[0109] The all-inorganic narrowband perovskite photodetector provided in this embodiment can be prepared by the method provided in Embodiment 1 or 2 above. The implementation process and technical effects are similar, and will not be described again here.

[0110] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for fabricating an all-inorganic narrowband perovskite photodetector, characterized in that, include: A glass substrate with an FTO electrode cathode is selected, and a groove is etched on the back side of the glass substrate; A TiO2 electron transport layer is prepared on the FTO electrode cathode; A perovskite filter layer was prepared in the groove using a sintering process. A perovskite light-absorbing layer is prepared on the TiO2 electron transport layer; wherein the perovskite light-absorbing layer and the perovskite filter layer are prepared using different all-inorganic perovskite materials; An electrode anode is deposited on the perovskite light-absorbing layer to obtain an all-inorganic narrowband perovskite photodetector. The material of the perovskite filter layer includes CsPbBr3; The preparation of the perovskite filter layer in the groove using a sintering process includes: CsBr solid powder and PbBr2 solid powder are mixed to obtain a mixed powder; the mixed powder is filled into the groove, and the entire sample is placed on a heating plate to melt the mixed powder into liquid CsPbBr3; the liquid CsPbBr3 is then cooled and crystallized, and finally slowly cooled to room temperature to form a CsPbBr3 perovskite filter layer in the groove. or, CsBr solid powder and PbBr2 solid powder were dissolved in dimethyl sulfoxide solution, and CsPbBr3 powder was obtained by co-deposition and drying. The CsPbBr3 powder was used to fill the groove, and the entire sample was placed on a heating plate to melt the CsPbBr3 powder into liquid CsPbBr3. The liquid CsPbBr3 was then cooled and crystallized, and finally slowly cooled to room temperature to form a CsPbBr3 perovskite filter layer in the groove.

2. The method for fabricating an all-inorganic narrowband perovskite photodetector according to claim 1, characterized in that, The groove is rectangular.

3. The method for fabricating an all-inorganic narrowband perovskite photodetector according to claim 1, characterized in that, The mass ratio of the CsBr solid powder to the PbBr2 solid powder is 0.

58.

4. The method for fabricating an all-inorganic narrowband perovskite photodetector according to claim 1, characterized in that, The material of the perovskite light-absorbing layer includes Cs2PbI2Cl2.

5. The method for fabricating an all-inorganic narrowband perovskite photodetector according to claim 4, characterized in that, The perovskite light-absorbing layer is prepared on the TiO2 electron transport layer, comprising: PbI2 solid was dissolved in dimethyl sulfoxide solution and stirred until PbI2 was completely dissolved to obtain PbI2 solution; CsCl solid was dissolved in methanol solution and stirred until CsCl was completely dissolved to obtain CsCl solution; In an N2 atmosphere, the PbI2 solution is spin-coated onto the TiO2 electron transport layer and then annealed to form a PbI2 layer on the TiO2 electron transport layer. The sample was immersed in CsCl solution to soak the PbI2 layer, and then the sample was annealed to form a Cs2PbI2Cl2 perovskite light absorption layer on the TiO2 electron transport layer.

6. The method for fabricating an all-inorganic narrowband perovskite photodetector according to claim 5, characterized in that, The nanostructure of Cs2PbI2Cl2 can be altered by adjusting the concentration of the CsCl solution, thereby forming a Cs2PbI2Cl2 perovskite light-absorbing layer comprising at least one nanostructure, such as nanowires, nanosheets, or thin films.

7. A fully inorganic narrowband perovskite photodetector, characterized in that, Prepared by the method according to any one of claims 1-6, comprising a glass substrate (1), an FTO electrode cathode (2), a TiO2 electron transport layer (3), a perovskite light absorption layer (4), and an electrode anode (5) arranged sequentially from bottom to top; The glass substrate (1) has a groove on its back side, and a perovskite filter layer (6) is provided in the groove; and the perovskite light absorption layer (4) and the perovskite filter layer (6) are made of different inorganic perovskite materials.

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