Preparation method and application of double-layer composite material

Abstract

The invention discloses a preparation method and application of a double-layer composite material. The preparation method of the double-layer composite material comprises the following steps: dissolving formamidine hydriodate, methyl ammonium iodide, lead iodide, stannous iodide and an additive in a mixed solution of dimethylformamide and dimethyl sulfoxide to prepare a perovskite precursor solution; a substrate is coated with the perovskite precursor solution in a spin coating mode; an anti-solvent is used for treating the precursor solution in the spin-coating process to obtain an intermediate-phase thin film; and carrying out annealing treatment on the intermediate phase thin film to obtain the fully crystallized double-layer perovskite thin film. By using the method, the problems that the photoelectric conversion efficiency is reduced, the utilization rate of light is not high, the temperature of a device is increased and the application field is limited due to the fact that an existing perovskite cell is poor in near-infrared light absorption can be solved; existing double-layer perovskite thin films are prepared in a layered mode, the number of preparation procedures is increased, and the production efficiency of batteries can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic cells, and in particular to a preparation method of a double-layer composite material and application thereof. Background Art

[0002] The application of perovskite thin film materials in the photovoltaic field has attracted much attention because of its advantages of high efficiency and low cost. However, general perovskite thin films also have some challenges and limitations. The existing perovskite thin films have poor absorption capacity for near-infrared light, which not only limits their application in specific fields (such as photoelectric conversion, photothermal conversion, optoelectronic devices, etc.), but may also lead to a series of technical and performance challenges.

[0003] The poor absorption capacity of perovskite films for near-infrared light will directly lead to low photoelectric conversion efficiency in applications such as solar cells. Since the solar spectrum contains a large amount of near-infrared light components, if it cannot be effectively utilized, the energy conversion efficiency of the entire system will be seriously affected. The unabsorbed near-infrared light is converted into heat energy inside the perovskite film, causing the device temperature to rise. High temperature will not only further reduce the photoelectric performance of perovskite, but may also cause problems such as material aging and decreased stability. Due to the limitations of perovskite films in near-infrared light absorption, their application areas will also be limited, especially in applications that require efficient use of near-infrared light (such as infrared imaging, infrared communications, etc.), which will affect the sensitivity and accuracy of the device.

[0004] The preparation method of double-layer perovskite film now mostly adopts the layered preparation method, first prepare the perovskite film on two substrates respectively, and then laminate the two perovskite films to form a double-layer perovskite film; or first prepare a layer of perovskite film, and then prepare another layer of perovskite film on this layer of perovskite film to obtain a double-layer perovskite film. The layered preparation method of double-layer perovskite film will increase the preparation process of perovskite battery, thereby reducing the production efficiency of perovskite battery, which is not conducive to industrial development. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a double-layer composite material and an application thereof. Through this method and application, the problems that the existing perovskite cells have poor absorption of near-infrared light, resulting in reduced photoelectric conversion efficiency, low light utilization, increased device temperature and limited application fields can be effectively solved. At the same time, the existing double-layer perovskite film preparation method can be solved, such as the large number of preparation steps and low production efficiency of perovskite cells.

[0006] The purpose of the present invention is achieved through the following technical solutions: A method for preparing a double-layer composite material comprises the following steps: S1. Formamidine hydroiodide (FAI), methylammonium iodide (MAI), lead iodide (PbI2), stannous iodide (SnI2) and additives are dissolved in a mixed solvent to prepare a perovskite precursor solution; the mixed solvent includes dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). The additive is a divalent tin halide, which is used to inhibit the oxidation of divalent tin ions in the perovskite precursor solution.

[0007] Since the divalent tin cations in the perovskite precursor solution are easily oxidized to tetravalent tin ions, the overall stability of the solution will be reduced, and the perovskite precursor solution will be more easily decomposed or deteriorated, and the film quality of the prepared perovskite film will also be reduced, and the oxidation reaction of the divalent tin ions in the perovskite precursor solution will also produce some harmful by-products, such as oxides, hydroxides, etc., which will cause certain harm to the environment and human health. Therefore, when preparing the perovskite precursor solution, the additive will be added thereto, wherein the additive is selected from divalent tin halides because divalent tin halides can inhibit the oxidation of divalent tin cations in the perovskite precursor solution, and divalent tin ions can generally have better stability in the perovskite precursor solution, avoid the decomposition and deterioration of the perovskite precursor solution, improve the film quality of the perovskite film, and also reduce the generation of harmful by-products, reducing the harm to the environment and human health.

[0008] S2. Spin-coat the perovskite precursor solution on a substrate; use an anti-solvent to treat the perovskite precursor solution during the coating (spin-coating) process to obtain an intermediate phase film; anneal the intermediate phase film to obtain a fully crystallized double-layer perovskite film. The anti-solvent can promote the rapid film formation and crystallization of the perovskite film. The double-layer perovskite film includes a first perovskite layer and a second perovskite layer. The first perovskite layer is composed of FASnI3, which is used to absorb near-infrared light and visible light. The second perovskite layer is composed of FA 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3 is used for secondary absorption of the visible light and the near-infrared light.

[0009] The single-layer perovskite film currently used has poor absorption capacity for near-infrared light, which will reduce the photoelectric conversion efficiency of the perovskite cell. Since the solar spectrum contains a large amount of near-infrared light components, if it cannot be effectively utilized, the unabsorbed near-infrared light will be converted into heat energy inside the perovskite film, causing the device temperature to rise. High temperature will not only further reduce the photoelectric performance of the perovskite, but also cause problems such as material aging and decreased stability. Compared with the single-layer perovskite film, the double-layer perovskite film has an additional first perovskite layer. The component of the first perovskite layer is FASnI3 and the band gap is about 1.4eV. Therefore, the first perovskite layer can absorb infrared light and visible light. The component of the second perovskite layer is FA 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3 and its band gap is about 1.25eV, which can perform secondary absorption of the visible light and the near-infrared light, thereby improving the utilization rate of sunlight by the double-layer perovskite film, and can also reduce the conversion of near-infrared light into heat energy inside the double-layer perovskite film, thereby avoiding the high temperature generated inside the device and thus avoiding reducing the photoelectric conversion performance of the perovskite cell.

[0010] The present invention adds the additive to the perovskite precursor solution, controls the content of divalent tin ions, and then obtains a double-layer perovskite layer (i.e., a double-layer perovskite film) through a common spin coating method and annealing treatment. The entire preparation process is simple, reduces production costs, and improves production efficiency.

[0011] Furthermore, in step S1 of the method for preparing the double-layer composite material, the divalent tin halide is stannous fluoride (SnF2), stannous chloride (SnCl2) or stannous bromide (SnBr2).

[0012] Furthermore, in step S1 of the method for preparing the double-layer composite material, the anti-solvent is chlorobenzene or ethyl acetate. In step S2 of the method for preparing the double-layer composite material, the annealing treatment adopts a two-step annealing, including a first annealing treatment and a second annealing treatment, the temperature of the first annealing treatment is 50-100°C and the annealing time is 1-10min, and the temperature of the second annealing treatment is 100-150°C and the annealing time is 1-10min. Preferably, the temperature of the first annealing treatment is 70°C and the annealing time is 2min, and the temperature of the second annealing treatment is 100°C and the annealing time is 7min.

[0013] At the same time, the present invention also provides a perovskite cell with a double-layer perovskite film, comprising a substrate, a hole transport layer, a double-layer perovskite film, an electron transport layer and a metal electrode, wherein the double-layer perovskite film is prepared by the preparation method of the above-mentioned double-layer composite material.

[0014] The use of a perovskite cell with a double-layer perovskite film can optimize the material's energy band structure and charge transfer characteristics, thereby improving the stability of the perovskite film. The double-layer perovskite film can further absorb near-infrared light through the double-layer structure, achieving full absorption and efficient conversion of sunlight. This can not only improve the photoelectric conversion efficiency of solar cells, but also broaden their application areas.

[0015] Furthermore, the perovskite cell is a formal perovskite cell or an inverted perovskite cell.

[0016] Furthermore, in the perovskite cell having a double-layer perovskite film, the hole transport layer comprises nickel oxide (NiO x ), 3-hexylthiophene (P3HT), cuprous thiocyanate (CuSCN), [2-(9h-carbazole-9-yl)ethyl]phosphonic acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACZ) and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACZ); the annealing temperature of the hole transport layer is 50-350°C, and the thickness of the hole transport layer is 10-70nm; the electron transport layer is fullerene (C 60 ) or [6,6]-phenyl-C71-butyric acid methyl ester (PC 71 BM), the thickness of the electron transport layer is 10-70nm.

[0017] Furthermore, when the perovskite cell adopts a trans structure, it also includes a hole blocking layer, which is arranged between the electron transport layer and the metal electrode. The material of the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer is 1-10nm.

[0018] Furthermore, in the perovskite cell having a double-layer perovskite film, the substrate is indium tin oxide (ITO) glass, fluorine-doped tin oxide (FTO) glass or aluminum-doped zinc oxide (AZO) glass.

[0019] In addition, the present invention also provides a photoelectric detection system, including a bias adjustment device, an optical power meter, an output device and at least one photodetector; the photodetector is the above-mentioned perovskite cell with a double-layer perovskite film; the photodetector and the optical power meter are both connected to the output device; the bias adjustment device is connected to the photodetector, and is used to apply a positive bias or a negative bias to the photodetector; the optical power meter is used to measure and output an optical power signal of the light to be measured, and is used to read the photocurrent signal of the light to be measured under the corresponding bias; the output device is used to receive the optical power signal and the photocurrent signal and output the spectral information of the light to be measured.

[0020] The photoelectric detection system can improve the detection capability of visible light and near-infrared light. Meanwhile, compared with the traditional photoelectric detection system, it does not require additional filters or spectroscopic devices, thus simplifying the structure of the system and reducing the requirements on the environment and equipment during use.

[0021] Furthermore, in the photoelectric detection system, a plurality of the photodetectors are distributed in a rectangular array to form a photodetector array, the plurality of the photodetectors share a top electrode, the plurality of the photodetectors in each row of the photodetector array share a row bottom electrode, and the plurality of the photodetectors in each column of the photodetector array share a column bottom electrode; the bias device is connected to the photodetector array for applying a bias to each photodetector; the photodetector array is also connected to an output device; the photodetector array can output a photoelectric signal of each photodetector.

[0022] Furthermore, the photoelectric detection system also includes a control circuit, which is connected to the photoelectric detector array and is used to control the readout logic of the photoelectric detector array.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: (1) The preparation method of the double-layer composite material of the present invention, when preparing the perovskite precursor solution, adding divalent tin halide thereto can inhibit the oxidation of divalent tin cations in the perovskite precursor solution. Compared with the single-layer perovskite film, the double-layer perovskite film can absorb further infrared light and visible light, thereby improving the utilization rate of the double-layer perovskite film for sunlight, and can also reduce the conversion of sunlight into heat energy inside the double-layer perovskite film, and the high temperature generated inside the device, thereby avoiding the reduction of the photoelectric conversion performance of the perovskite cell. Additives are added to the perovskite precursor solution, and a common spin coating method and annealing treatment are used to obtain a double-layer perovskite layer. The entire preparation process is simple, reducing production costs and improving production efficiency.

[0024] (2) The perovskite cell with a double-layer perovskite film of the present invention has a double-layer structure. The double-layer perovskite film can further absorb visible light and near-infrared light to achieve efficient conversion of sunlight. This can not only improve the photoelectric conversion efficiency of solar cells, but also broaden their application fields.

[0025] (3) The photoelectric detection system of the present invention uses a perovskite cell with a double-layer perovskite film as a photodetector, which has a high light response in the visible to near-infrared band. Compared with the traditional photoelectric detection system, the photoelectric detection system does not require additional filters or spectroscopic devices, which simplifies the structure of the system and reduces the requirements for the environment and equipment during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is further described in detail below with reference to the accompanying drawings.

[0027] Figure 1 This is a preparation flow chart of the preparation method of the double-layer composite material described in Example 1 of the present invention.

[0028] Figure 2 This is a schematic structural diagram of an inverted perovskite cell of a perovskite cell having a double-layer perovskite film as described in Example 2 of the present invention.

[0029] Figure 3 This is a connection diagram of the photoelectric detection system described in Example 3 of the present invention.

[0030] Figure 4 This is a graph of the IV characteristic of the detector prepared in Example 3 of the present invention when detecting light of different wavelengths.

[0031] Figure 5 This is a connection diagram of the photoelectric detector array distribution of the photoelectric detection system described in Example 4 of the present invention.

[0032] As shown in the figure: 1-substrate; 2-hole transport layer; 3-double-layer perovskite film; 31-first perovskite layer; 32-second perovskite layer; 4-electron transport layer; 5-hole blocking layer; 6-metal electrode. DETAILED DESCRIPTION

[0033] The following is an explanation of the implementation of the present invention by specific specific embodiments. People familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example 1

[0036] like Figure 1 As shown, this embodiment provides a method for preparing a double-layer composite material, comprising the following steps: S1. Preparation of perovskite precursor solution: S11. Weigh a certain amount of formamidine hydroiodide (FAI), methylammonium iodide (MAI), lead iodide (PbI2), stannous iodide (SnI2) and additives respectively for use; mix dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to obtain a mixed solvent for use. The additive is a divalent tin halide, which is used to inhibit the oxidation of divalent tin ions in the perovskite precursor solution. The divalent tin halide is any one of stannous fluoride (SnF2), stannous chloride (SnCl2) and stannous bromide (SnBr2).

[0037] S12. Dissolve the weighed formamidine hydroiodide (FAI), methylammonium iodide (MAI), lead iodide (PbI2), stannous iodide (SnI2) and additives in a mixed solvent to prepare a perovskite precursor solution.

[0038] S2. Preparation of double-layer perovskite film 3: S21. Spin coating the perovskite precursor solution obtained in step S12 onto the substrate to form a precursor wet film.

[0039] S22. During the spin coating process, the precursor wet film is subjected to vacuum-assisted crystallization using an anti-solvent chlorobenzene or ethyl acetate to obtain an intermediate phase film. The anti-solvent can promote rapid film formation and crystallization of the perovskite film.

[0040] S23. The intermediate phase film obtained in step S22 is subjected to annealing treatment, wherein the annealing treatment adopts a two-step annealing treatment, wherein the first step annealing temperature is 70°C, the annealing time is 2 minutes, and the second step annealing temperature is 100°C, the annealing time is 7 minutes. After the annealing treatment is completed, a double-layer perovskite film 3 with a thickness of 500 nm and fully crystallized is prepared.

[0041] The double-layer perovskite film 3 includes a first perovskite layer 31 and a second perovskite layer 32 .

[0042] The first perovskite layer 31 is composed of FASnI3 and is used to absorb near-infrared light and visible light.

[0043] The composition of the second perovskite layer 32 is FA 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3 is used for secondary absorption of the visible light and the near-infrared light.

[0044] Compared with a single-layer perovskite film, the double-layer perovskite film 3 can absorb further infrared light and visible light, thereby improving the utilization rate of the double-layer perovskite film 3 for sunlight, and can also reduce the conversion of sunlight into heat energy inside the double-layer perovskite film 3, and the high temperature generated inside the device, thereby avoiding reducing the photoelectric conversion performance of the perovskite cell. Adding additives to the perovskite precursor solution and using a common spin coating method and annealing treatment can obtain a double-layer perovskite layer, which has a simple preparation process, reduces production costs, and improves production efficiency. Example 2

[0045] Based on the double-layer perovskite film prepared in the embodiment, Figure 2 As shown, this embodiment provides a perovskite cell with a double-layer perovskite film, which includes a substrate 1, a hole transport layer 2, a double-layer perovskite film 3, an electron transport layer 4 and a metal electrode 6.

[0046] The substrate 1 is indium tin oxide (ITO) glass, fluorine-doped tin oxide (FTO) glass or aluminum-doped zinc oxide (AZO) glass.

[0047] The hole transport layer 2 is nickel oxide (NiO x), 3-hexylthiophene (P3HT), cuprous thiocyanate (CuSCN), [2-(9h-carbazole-9-yl)ethyl]phosphonic acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACZ) and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACZ); the annealing temperature of the hole transport layer 2 is 50-350°C, and the thickness of the hole transport layer 2 is 10-70nm.

[0048] The double-layer perovskite film 3 is prepared by the preparation method of the double-layer composite material in Example 1.

[0049] The electron transport layer 4 is fullerene (C 60 ) or [6,6]-phenyl-C71-butyric acid methyl ester (PC 71 BM), the thickness of the electron transport layer 4 is 10-70nm.

[0050] The material of the metal electrode 6 is silver, and the thickness of the metal electrode 6 is about 200 nm.

[0051] The perovskite cell using the double-layer perovskite film 3 can optimize the energy band structure and charge transfer characteristics of the material, thereby improving the stability of the perovskite film. The double-layer perovskite film 3 can further absorb near-infrared light through the double-layer structure, achieving full absorption and efficient conversion of sunlight. This can not only improve the photoelectric conversion efficiency of the solar cell, but also broaden its application field.

[0052] Let's take the inverse perovskite battery as an example. Figure 2 The figure shows an inverse perovskite cell, which includes a substrate 1, a hole transport layer 2, a double-layer perovskite film 3, an electron transport layer 4, a hole blocking layer 5 and a metal electrode 6 stacked and connected from bottom to top. The double-layer perovskite film includes a first perovskite layer 31 and a second perovskite layer 32. The material of the hole blocking layer 5 is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer 5 is 1-10nm.

[0053] The preparation process of the inverse perovskite cell is as follows: A. Preparation of the substrate 1: The substrate 1 was ultrasonically cleaned with anhydrous ethanol, and after being fully dried, was subjected to UV-ozone treatment for 20 minutes.

[0054] B. Preparation of the hole transport layer 2: In this embodiment, the hole transport layer 2 (NiO x), the substrate 1 is transferred to the base of the sputtering equipment, and NiO x The target is fixed at the target position of the sputtering gun or sputtering chamber. Set the relevant parameters of the sputtering equipment and set the gas to argon. Evacuate the vacuum to 10 -6 Sputtering was started after T, and the deposition rate was controlled to be 2nm / min. After 40nm of deposition, the sample was taken out for post-processing.

[0055] C. Preparation of the double-layer perovskite film 3: Prepare a perovskite precursor solution. In this embodiment, a certain amount of FAI, PbI2, MAI, SnI2 and the additives are weighed and dissolved in a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to prepare the perovskite precursor solution. The perovskite precursor solution is applied on the top surface of the hole transport layer 2 by spin coating. 200 μL of anti-solvent chlorobenzene is added 20s before the end of spin coating. The double-layer perovskite film 3 is annealed in two steps, with the first step annealing temperature of 70°C and the annealing time of 2min, and the second step annealing temperature of 100°C and the annealing time of 7min. A double-layer perovskite film 3 with a thickness of 500nm is prepared. The obtained double-layer perovskite film 3 includes a first perovskite layer 31 and a second perovskite layer 32.

[0056] D. Preparation of the electron transport layer 4 and the hole blocking layer 5: the thickness of the electron transport layer 4 is 30 nm; the material of the hole blocking layer 5 is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer is 6 nm.

[0057] E. Preparation of the metal electrode 6: The material of the metal electrode 6 in this embodiment is silver, and the thickness of the metal electrode 6 is 200 nm. Example 3

[0058] Based on Example 2, this embodiment further provides a photoelectric detection system, which includes a photoelectric detector, a bias adjustment device, an optical power meter and an output device. In the photoelectric detection system, at least one perovskite cell with a double-layer perovskite film as described in Example 2 is used as a photoelectric detector.

[0059] The photoelectric detector and the optical power meter are both connected to the output device.

[0060] The bias voltage adjustment device is connected to the photodetector and is used to apply a positive bias voltage or a negative bias voltage to the photodetector.

[0061] The optical power meter is used to measure and output the optical power signal of the light to be measured, and is used to read the photocurrent signal of the light to be measured under the application of the corresponding bias voltage.

[0062] The output device is used to receive the optical power signal and the photocurrent signal and output the spectrum information of the light to be measured.

[0063] The identification method of the output device is as follows: (1) Calibration of the test system: The test system of the output device is calibrated by a known single wavelength light source. n The light sources are incident on the photoelectric detection system one by one, and the optical power P(λ n ), the photodetector obtains the photocurrent I(λ under the corresponding bias voltage n ,V). Then the photocurrent of each wavelength is normalized according to the optical power, that is, I'(λ n ,V)=I(λ n ,V) / P(λ n ). Label the data of each wavelength λ n .

[0064] (2) Function fitting: The obtained data is brought into the neural network for training, and a function of the IV characteristic curve and wavelength of the incident light can be fitted.

[0065] (3) Measurement of actual spectrum: After obtaining the IV characteristic curve of the unknown light, the spectrum information of the unknown light can be obtained by solving it using the function.

[0066] like Figure 4 The IV characteristic curves of the prepared detector under the detection of light of different wavelengths, covering red, green, blue and near-infrared light in the visible light. At the same time, its dark current was measured, such as Figure 4 As shown in the figure, the detector detection range can be extended from visible light to near infrared. The photocurrent of red light reaches 10 -3 A, the photocurrent of near-infrared light also reached 10 -4 A. It can be seen that the detector can be used in fields such as infrared night vision. At the same time, the photoelectric response curves of different wavelengths also have a high degree of distinction, which provides a good basis for spectral recognition. Example 4

[0067] like Figure 5 As shown, this embodiment further provides a photoelectric detection system based on the embodiment 3. In addition to the structure described in the embodiment 3, the photoelectric detection system also includes a control circuit.

[0068] In the photoelectric detection system, a plurality of the photoelectric detectors are distributed in a rectangular array to form a photoelectric detector array, the plurality of photoelectric detectors share a top electrode, each row of photoelectric detectors in the photoelectric detector array shares a row bottom electrode, and each column of photoelectric detectors in the photoelectric detector array shares a column bottom electrode. The top electrode of the photoelectric detector array uses an ITO electrode, and both the row bottom electrode and the column bottom electrode use copper electrodes.

[0069] The bias device is connected to the photodetector array and is used to apply a bias voltage to each photodetector in the photodetector array.

[0070] The photodetector array is also connected to an output device, and the photodetector array can output the photoelectric signal of each photodetector.

[0071] The control circuit is connected to the photodetector array and is used to control the readout logic of the photodetector array. The control circuit first selects a specific row through the row bottom electrode, and then controls the column bottom electrode through the control circuit to select a specific photodetector and reads out the photocurrent signal under the bias and transmits it to the output device. Under the condition that the applied bias remains unchanged, the control circuit repeats the above steps by controlling different row bottom electrodes and column bottom electrodes to obtain the photocurrent signal of the photodetector array under a specific bias. The bias device changes the applied bias and repeatedly reads the entire photodetector array. Thus, the output device obtains the IV curve of each photodetector, and obtains the spectrum of the light signal received by each photodetector in the array through function recovery. The obtained spectral information can be used to realize color imaging of the photodetector array. Since its detection wavelength can reach the near-infrared range, the photodetector array can be used in all-weather imaging security and other fields.

[0072] Other aspects of the present invention that are not described in detail are all conventional techniques known to those skilled in the art.

[0073] It should be noted that the terms "comprises", "includes" or any other variations are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0074] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific implementation methods. Any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a double-layer composite material, characterized in that: The following steps are involved: S1. dissolving formamidine hydroiodide (FAI), methylammonium iodide (MAI), lead iodide (PbI2), stannous iodide (SnI2) and an additive in a mixed solvent to prepare a perovskite precursor solution; the mixed solvent includes dimethylformamide (DMF) and dimethyl sulfoxide (DMSO); the additive is a divalent tin halide, which is used to inhibit the oxidation of divalent tin ions in the perovskite precursor solution; S2. coating the perovskite precursor solution on a substrate; During the coating process, the perovskite precursor solution is treated with an anti-solvent to obtain an intermediate phase film; the intermediate phase film is annealed to obtain a fully crystallized double-layer perovskite film; The double-layer perovskite film comprises a first perovskite layer and a second perovskite layer; the first perovskite layer is composed of FASnI3, which is used to absorb near-infrared light and visible light; the second perovskite layer is composed of FA 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3 is used for secondary absorption of the visible light and the near-infrared light.

2. The method for preparing the double-layer composite material according to claim 1, characterized in that: The divalent tin halide is stannous fluoride (SnF2), stannous chloride (SnCl2) or stannous bromide (SnBr2).

3. The method for preparing the double-layer composite material according to claim 1, characterized in that: The anti-solvent is chlorobenzene or ethyl acetate, the annealing treatment includes a first annealing treatment and a second annealing treatment, the temperature of the first annealing treatment is 50-100° C. and the annealing time is 1-10 min, and the temperature of the second annealing treatment is 100-150° C. and the annealing time is 1-10 min.

4. A perovskite cell having a double-layer perovskite film, characterized in that: The invention comprises a substrate, a hole transport layer, a double-layer perovskite film, an electron transport layer and a metal electrode, wherein the double-layer perovskite film is prepared by the preparation method of the double-layer composite material according to any one of claims 1 to 3.

5. The perovskite cell with a double-layer perovskite film according to claim 4, characterized in that: The perovskite cell is a formal perovskite cell or an inverted perovskite cell.

6. The perovskite cell with a double-layer perovskite film according to claim 4, characterized in that: The hole transport layer comprises nickel oxide (NiO x ), 3-hexylthiophene (P3HT), cuprous thiocyanate (CuSCN), [2-(9h-carbazole-9-yl)ethyl]phosphonic acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACZ) and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACZ); the annealing temperature of the hole transport layer is 50-350°C, and the thickness of the hole transport layer is 10-70nm; the electron transport layer is fullerene (C 60 ) or [6,6]-phenyl-C71-butyric acid methyl ester (PC 71 BM), the thickness of the electron transport layer is 10-70nm.

7. The perovskite cell with a double-layer perovskite film according to claim 5, characterized in that: When the perovskite cell adopts a trans structure, it also includes a hole blocking layer, which is arranged between the electron transport layer and the metal electrode; the material of the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer is 1-10nm.

8. A photoelectric detection system, characterized in that: It comprises a bias adjustment device, an optical power meter, an output device and at least one photodetector; the photodetector is a perovskite cell with a double-layer perovskite film as described in any one of claims 4 to 7; the photodetector and the optical power meter are both connected to the output device; the bias adjustment device is connected to the photodetector, and is used to apply a positive bias or a negative bias to the photodetector; the optical power meter is used to measure and output an optical power signal of the light to be measured, and is used to read a photocurrent signal of the light to be measured under a corresponding bias; the output device is used to receive the optical power signal and the photocurrent signal and output the spectral information of the light to be measured.

9. The photoelectric detection system according to claim 8, characterized in that: A plurality of the photodetectors are distributed in a rectangular array to form a photodetector array, wherein the plurality of the photodetectors share a top electrode, the plurality of the photodetectors in each row of the photodetector array share a row bottom electrode, and the plurality of the photodetectors in each column of the photodetector array share a column bottom electrode; the bias device is connected to the photodetector array for applying a bias to each photodetector; the photodetector array is also connected to an output device; the photodetector array can output a photoelectric signal of each photodetector.

10. The photoelectric detection system according to claim 9, characterized in that: The device also includes a control circuit, which is connected to the photodetector array and is used to control the readout logic of the photodetector array.

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