Two-dimensional large-area organic-inorganic hybrid perovskite and its preparation, photodetector

Abstract

The present invention discloses a two-dimensional large-area organic-inorganic hybrid perovskite and its preparation method and photodetector. The preparation method includes the following steps: (1) heating a halide precursor powder and a surface passivator to different temperatures respectively to enable the surface passivator to adsorb on the surface of the reaction source, thereby passivating the surface with the most adsorbed surface passivator; growing a two-dimensional halide template on a substrate by chemical vapor deposition; (2) hybridizing by a gas-phase transformation method using an organic salt containing CH3NH3 + or CH(NH2)2 + to convert the two-dimensional halide template into an organic-inorganic hybrid perovskite. The hybrid perovskite prepared by the present invention has a large size, the maximum single crystal wafer area can reach 500 microns, the film area is 1.5 cm × 1.5 cm, high quality and good uniformity. The photodetector containing the hybrid perovskite prepared by the present invention has excellent performance and a fast response time, and its response time is less than 10 μs.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite, and more specifically, relates to a two-dimensional large-area organic-inorganic hybrid perovskite and its preparation method, and a photodetector. Background Art

[0002] In 1839, German chemist and mineralogist Gustav Rose discovered a new mineral in the Ural Mountains within the territory of Russia. Later, it was found that its main component is CaTiO3, and it was named perovskite. In recent years, halide perovskite materials such as MAPbX3 and CsPbX3 (X = Cl, Br, I) with the same structure have been successively discovered and have attracted much attention due to their excellent optoelectronic properties. These materials have a high absorption coefficient, strong photoluminescence characteristics, excellent carrier mobility, and a long carrier diffusion distance. When the halide perovskite is used as a light-absorbing material, the power conversion efficiency (PCE) of the solar cell has been greatly improved from 3.8% to 25.7% in only more than 10 years. In addition, perovskite materials are also widely used in light-emitting diodes, lasers, radiation detection and other fields. Due to the characteristics that the optoelectronic properties of two-dimensional perovskite change with thickness and halogen, it has broad application prospects in integrated optoelectronic devices. So far, the preparation methods of two-dimensional halide perovskite have been widely studied, such as solution method and mechanical exfoliation method. However, when preparing a two-dimensional halide perovskite film by the solution method, there are disadvantages of poor film crystallinity and difficult thickness control. The mechanical exfoliation method can obtain high-quality perovskite nanosheets, but the obtained nanosheets are small in size and irregular in shape, which cannot meet the needs of large-scale research and application.

[0003] Chemical vapor deposition is a solvent-free material preparation method, which can minimize the defects of the material and provide an effective way for the preparation of high-quality, large-area and thickness-tunable two-dimensional perovskite materials. At present, chemical vapor deposition is mostly applied to the preparation of two-dimensional all-inorganic perovskite materials with similar melting points of precursors. Due to the large difference in melting points of organic-inorganic hybrid perovskite precursors, vapor conversion method has attracted extensive attention in the preparation of two-dimensional hybrid halide perovskite. This method first prepares a halide template with a high melting point, and then uses the vapor conversion method to convert the halide template into perovskite. However, the currently prepared two-dimensional halide templates are small in size and large in thickness, which greatly hinders the large-scale preparation and development and utilization of two-dimensional organic-inorganic hybrid perovskite materials. Summary of the Invention

[0004] In view of the above defects or improvement requirements of the prior art, the present invention provides a two-dimensional large-area organic-inorganic hybrid perovskite and its preparation method and photodetector. The purpose is to utilize the different surface passivation degrees of the surface passivator on different surfaces of the halide to prepare a two-dimensional large-area halide template, and hybridize the organic small molecule with the halide precursor to successfully convert it into a hybrid perovskite material. This method solves the problems of small size, large thickness, poor quality, and poor stability in the preparation of two-dimensional hybrid perovskites, and is easy to integrate with devices, laying a foundation for the preparation of hybrid perovskite array devices.

[0005] To achieve the above object, according to one aspect of the present invention, a method for preparing a two-dimensional large-area organic-inorganic hybrid perovskite is provided, including the following steps:

[0006] (1) Heat the halide precursor powder and the surface passivator to different temperatures respectively, so that the surface passivator adsorbs on the surface of the reaction source, thereby passivating the surface with the most adsorbed surface passivator; use chemical vapor deposition to grow a two-dimensional halide template on the substrate;

[0007] (2) Through gas-phase transformation, use an organic salt containing CH3NH3 + or CH(NH2)2 + to hybridize and convert the two-dimensional halide template into an organic-inorganic hybrid perovskite.

[0008] Preferably, the surface passivator is a hydrophobic organic compound containing an amino group. Preferably, the surface passivator is one of (RNH3)X, RNH4, R2NH2X, R3NHX, and R4NX, where R is an alkyl group with 4-18 carbon atoms, and X is Cl, Br, or I.

[0009] Preferably, the surface passivator is one of butylamine hydrochloride (BACl, CH3(CH2)3NH3Cl), butylamine hydrobromide (BABr, CH3(CH2)3NH3Br), butylamine hydroiodide (BAI, CH3(CH2)3NH3I), pentylamine hydrochloride (PACl, CH3(CH2)4NH3Cl), pentylamine hydrobromide (PABr, CH3(CH2)4NH3Br), pentylamine hydroiodide (PAI, CH3(CH2)4NH3I), hexylamine hydrochloride (HACl, CH3(CH2)5NH3Cl), hexylamine hydrobromide (HABr, CH3(CH2)5NH3Br), hexylamine hydroiodide (HAI, CH3(CH2)5NH3I), butylamine (CH3(CH2)3NH2), pentylamine (CH3(CH2)4NH2), or hexylamine (CH3(CH2)5NH2).

[0010] Preferably, the organic salt is one of methylammonium chloride (MACl), methylammonium bromide (MABr), methylammonium iodide (MAI), formamidinium chloride (FACl), formamidinium bromide (FABr), or formamidinium iodide (FAI).

[0011] Preferably, in step (1), heating the halide precursor powder and the surface passivator to different temperatures respectively: heating the halide precursor powder to 250 - 450 °C, heating the surface passivator to 150 - 250 °C, and the heating time is 10 minutes - 5 hours.

[0012] Preferably, the halide precursor powder is one of SnCl2, SnBr2, SnI2, PbCl2, PbBr2, PbI2, CuCl2, CuBr2, MnCl2, MnBr2, MnI2, CdCl2, CdBr2, and CdI2.

[0013] Preferably, the gas-phase conversion method is as follows: under the conditions of no oxygen and less than 1% - 10% of atmospheric pressure, the heating temperature is 70 - 160 °C, and the reaction time is 15 minutes - 3 hours.

[0014] According to another aspect of the present invention, a two-dimensional large-area organic-inorganic hybrid perovskite is provided. The area of the two-dimensional large-area organic-inorganic hybrid perovskite can reach 500 microns; preferably, when the two-dimensional large-area organic-inorganic hybrid perovskite is placed in the atmosphere for 180 days, there is no degradation on the surface and no decline in the luminescence characteristics.

[0015] According to yet another aspect of the present invention, a photodetector is provided. The photodetector includes a two-dimensional large-area organic-inorganic hybrid perovskite; the response time of the photodetector is less than 10 μs; preferably, when the photodetector is placed in the atmosphere for 180 days, the light detection performance does not decline.

[0016] According to still another aspect of the present invention, a device for preparing a two-dimensional large-area organic-inorganic hybrid perovskite is provided. The device includes: a tube furnace, a heating jacket, a quartz tube with both ends open, a quartz tube with only one end open, an Al2O3 porcelain boat, and a quartz U-shaped groove.

[0017] Among them, the tube furnace and the heating sleeve are sequentially arranged on the outer wall of the quartz tube with both ends open, and are used to heat different positions of the quartz tube with both ends open; along the direction of the protective atmosphere entering inside the quartz tube with both ends open, an Al2O3 ceramic boat and a quartz tube with only one end open are sequentially arranged at intervals, and the open end of the quartz tube with only one end open faces the setting direction of the Al2O3 ceramic boat, and the Al2O3 ceramic boat is located at the heating center T1 of the tube furnace, and the closed end of the quartz tube with only one end open is located at the heating center T2 of the heating sleeve. The quartz tube with only one end open is placed in a quartz U-shaped groove, and the substrate is erected on the top of the quartz U-shaped groove;

[0018] The Al2O3 ceramic boat is provided with a halide precursor powder, and the closed end of the quartz tube with only one end open is provided with a surface passivator.

[0019] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, at least the following beneficial effects can be achieved.

[0020] (1) In the present invention, taking the halide precursor powder as the source, the surface passivator and the halide precursor powder are heated to different temperatures respectively, so that the surface passivator is adsorbed on different surfaces of the halide. Since the adsorption energy of different surfaces of the halide precursor powder for the surface passivator is different, the surface with the most adsorbed passivator is passivated, its surface energy is reduced, the growth of this surface is passivated, and finally a two-dimensional large-area halide template is formed. Then, the halide template is converted into a hybrid perovskite by organic small molecule hybridization. The hybrid perovskite prepared by the present invention has large size, the maximum area can reach 500 microns, high quality and good uniformity. The photodetector containing the hybrid perovskite prepared by the present invention has excellent performance and fast response time, and its response time is less than 10 μs.

[0021] (2) In the present invention, a hydrophobic organic compound containing an amino group is used as the surface passivator. Since the hydrophobic long-chain organic compound is adsorbed on the surface of the hybrid perovskite, the stability of the perovskite is greatly improved, promoting the development of its practical application. The hybrid perovskite prepared by the present invention is placed in the air for 180 days, and its morphology and luminescence characteristics do not change significantly; while the same perovskite thin film prepared by the spin-coating method in the prior art is placed for 12 hours under the same conditions, surface degradation occurs, and the luminescence intensity drops significantly. After being placed for 2 days, a large amount of degradation appears on the film surface, and there is almost no luminescence characteristic, and the degraded substance is no longer a perovskite material. The hybrid perovskite material prepared by the present invention is placed in the air for 180 days, and its light detection performance does not change significantly; while the same perovskite thin film prepared by the spin-coating method in the prior art is placed for 2 days under the same conditions, the light detection performance drops significantly, and after being placed for 3 days under the same conditions, the light detection performance drops significantly, and the perovskite material is no longer in the photodetector channel after degradation.

[0022] (3) It is found through research in the present invention that self-limiting chemical vapor deposition can be achieved only when the heating temperatures of the halide precursor powder and the surface passivator are different, and a two-dimensional large-area halide template can be obtained; this is one of the necessary conditions for the present invention to be able to prepare two-dimensional large-area organic-inorganic hybrid perovskites. It is necessary to satisfy that the growth temperature of the passivated halide is between the halide precursor powder and the evaporation temperature of the passivator. Therefore, the ordinary tube furnace is improved in the present invention. A heating jacket is creatively set, different substances are respectively placed at the centers of the tube furnace and the heating jacket, and the setting position of the substrate is also regulated, thereby realizing the successful preparation of two-dimensional large-area organic-inorganic hybrid perovskites.

[0023] Specifically, the halide powder is placed in an Al2O3 porcelain boat and placed at the central position of the tube furnace, and the set temperature is T1. The passivator is placed in a small quartz tube with one end open and one end sealed. The open end of the small quartz tube is adjacent to the Al2O3 porcelain boat of the halide precursor powder, and the closed end is placed at the central position of the heating jacket. The gas used as the carrier gas and the protective gas is introduced from the upstream inlet of the tube furnace. The evaporated halide volatilizes along the gas direction to the downstream of the tube furnace. At the same time, the gas changes the evaporated passivator in the opposite direction, and the passivator also volatilizes to the downstream of the tube furnace. Among them, the substrate is set between T1 and T2, and the distance from T1 is 12 cm, and a relatively large number and thin two-dimensional halides can be realized. If the position of the substrate is set at a distance of 14 cm from T1, two-dimensional halides with very large sizes are likely to appear. If the position of the substrate is set farther away from T1, two-dimensional halides with a relatively large number and large sizes are likely to appear. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the device for self-limiting chemical vapor deposition in a tube furnace in Step 1 of Example 1, using lead bromide (PbBr2) as the precursor and hexylammonium hydrobromide (HABr) with a long-chain organic compound as the surface passivator;

[0025] Figure 2 It is an optical microscope picture of a 230-micron PbBr2 single crystal grown on a mica substrate at a distance of 16 cm from T1 in Example 2;

[0026] Figure 3 It is an optical microscope picture of a sub-millimeter PbBr2 single crystal grown on a mica substrate at a distance of 14 cm from T1 in Example 3;

[0027] Figure 4 It is an optical microscope picture of a PbBr2 single crystal grown on a silicon oxide substrate in Example 4;

[0028] Figure 5 It is a photo of a 1.5 cm × 1.5 cm PbBr2 thin film grown on a mica substrate in Example 5;

[0029] Figure 6 It is the Raman spectrum of the large-area PbBr2 template single crystal wafer in Example 2;

[0030] Figure 7 It is the Raman mapping of the large-area PbBr2 template single crystal wafer in Example 2;

[0031] Figure 8 It is the scanning electron microscope image of the large-area PbBr2 template single crystal wafer in Example 2;

[0032] Figure 9 It is the elemental composition analysis of the large-area PbBr2 template single crystal wafer in Example 2;

[0033] Figure 10 It is the schematic diagram of the device in Step 2 of Example 1, where large-area PbBr2 is used as a template and the organic small molecule methylammonium hydrobromide (MABr) is intercalated, and the gas-phase transformation process occurs in a tube furnace;

[0034] Figure 11 It is the optical microscope image of converting 230-μm PbBr2 single crystal into MAPbBr3 in Example 1;

[0035] Figure 12 It is the optical microscope image of converting submillimeter PbBr2 single crystal into MAPbBr3 in Example 6;

[0036] Figure 13 In (a), it is the X-ray diffraction pattern of the large-area PbBr2 template in Example 2; Figure 13 In (b), it is the X-ray diffraction pattern of MAPbBr3 perovskite in Example 1;

[0037] Figure 14 It is the photoluminescence spectrum and absorption spectrum of different wavelengths of laser of the large-area MAPbBr3 perovskite under 532-nm laser irradiation in Example 1;

[0038] Figure 15 It is the device schematic diagram of the large-area MAPbBr3 perovskite in Example 7;

[0039] Figure 16 It is the current-voltage curve of the large-area MAPbBr3 perovskite device in the dark state and under 532-nm laser irradiation in Example 7;

[0040] Figure 17 It is the on-state curve of the light response of the large-area MAPbBr3 perovskite device in Example 7;

[0041] Figure 18In Example 7, it is the off-state curve of the large-area MAPbBr3 perovskite device's light response;

[0042] Figure 19 In Example 1, it is an optical microscope image of the morphology change of the MAPbBr3 perovskite prepared by the conversion method over time in an atmospheric environment;

[0043] Figure 20 In Comparative Example 1, it is an optical microscope image of the morphology change of the MAPbBr3 perovskite prepared by the traditional spin-coating method over time in an atmospheric environment;

[0044] Figure 21 In Example 1 and Comparative Example 1, it is a graph showing the change of the photoluminescence intensity of the MAPbBr3 perovskite prepared by the spin-coating method and the conversion method over time in an atmospheric environment; where the conversion method - MAPbBr3 is the MAPbBr3 perovskite prepared in Example 1, and the spin-coating method - MAPbBr3 is the MAPbBr3 perovskite prepared in Comparative Example 1;

[0045] Figure 22 In Example 1 and Comparative Example 1, it is a graph showing the change of the responsivity of the MAPbBr3 perovskite devices prepared by the spin-coating method and the conversion method to a 532 nm laser over time in an atmospheric environment; where the conversion method - MAPbBr3 is the MAPbBr3 perovskite prepared in Example 1, and the spin-coating method - MAPbBr3 is the MAPbBr3 perovskite prepared in Comparative Example 1.

[0046] In all the drawings, the same reference numerals are used to represent the same elements or structures, where:

[0047] 1 - tubular furnace; 2 - heating jacket; 3 - quartz tube with both ends open, 4 - quartz tube with only one end open. Detailed implementation manners

[0048] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] Example 1

[0050] This example provides a two-dimensional large-area organic-inorganic hybrid perovskite, and its preparation process is as follows:

[0051] Step 1: Figure 1It is a schematic diagram of the specific implementation of the self-limiting chemical vapor deposition method involved in the present invention. The PbBr2 precursor powder is placed at the center (T1) of the tube furnace. Since the growth temperature of the PbBr2 template is higher than the evaporation temperature of HABr, the HABr powder is placed at the center (T2) of the external heating jacket of the furnace. The quartz tube is flushed with argon to discharge air. Then argon is introduced until the air pressure in the quartz tube is equal to the atmospheric pressure, and heating is started. The temperature is increased to 370 °C (T1) and 225 °C (T2) at a heating rate of 20 °C / min, and then held for 3 hours. Then the quartz tube is naturally cooled to room temperature, and the sample is taken out. A large-area PbBr2 template is obtained on the substrate. Among them, the substrate is a mica substrate, and the distance between the mica substrate and T1 is 16 cm.

[0052] Step 2: Figure 10 It is a schematic diagram of the specific implementation of the conversion of a large-area PbBr2 template into MAPbBr3 perovskite involved in the present invention. The MABr powder is placed at the center of the tube furnace, and the substrate carrying the large-area PbBr2 is placed at a position 5-6 cm away from the center of the tube furnace. The quartz tube is flushed with argon to discharge air. Then argon is introduced until the air pressure in the quartz tube reaches 1% of the atmospheric pressure, and heating is started. The temperature is increased to 120 °C at a heating rate of 20 °C / min and held for between 15 minutes and 2 hours. Then the tube furnace is naturally cooled to room temperature, and the sample is taken out. A two-dimensional large-area organic-inorganic hybrid perovskite is obtained.

[0053] Example 2

[0054] This example provides a method for growing a large-area single crystal of PbBr2 on a substrate. That is, only Step 1 in Example 1 is completed in this example, and there is no Step 2. Among them, the substrate is a mica substrate, and the distance between the mica substrate and T1 is 16 cm.

[0055] Example 3

[0056] This example provides a method for growing a large-area single crystal of PbBr2 on a substrate. That is, only Step 1 in Example 1 is completed in this example, and there is no Step 2. Among them, the substrate is a mica substrate, and the distance between the mica substrate and T1 is 14 cm.

[0057] Example 4

[0058] This example provides a method for growing a large-area single crystal of PbBr2 on a substrate. That is, only Step 1 in Example 1 is completed in this example, and there is no Step 2. Among them, the substrate is a silicon oxide substrate.

[0059] Example 5

[0060] This embodiment provides a method for growing a large-area PbBr2 film on a substrate. That is, only step 1 in embodiment 1 is completed in this embodiment, and there is no step 2. The difference between this embodiment and embodiment 2 is that in step 1, after the quartz tube is cleaned with argon, argon is introduced until the air pressure in the quartz tube reaches 100 Pa, and then heating is started.

[0061] Embodiment 6

[0062] This embodiment provides a two-dimensional large-area organic-inorganic hybrid perovskite, which is prepared by using the same steps 1 and 2 as in embodiment 1. The difference between this embodiment and embodiment 1 is that in step 1, the substrate is a mica substrate, and the distance between the mica substrate and T1 is 14 cm.

[0063] Embodiment 7

[0064] This embodiment provides a MAPbBr3 perovskite lateral device, specifically:

[0065] Using mica as the substrate and the pre-etched device pattern on the stainless steel plate as the template, Cr / Au with thicknesses of 10 / 90 nm are deposited on the surface of the MAPbBr3 perovskite prepared in embodiment 1 to form a lateral device. By applying a suitable bias voltage and light illumination to the source and drain electrodes, the device exhibits excellent optoelectronic properties, and a fast optical response is obtained by applying a light pulse.

[0066] Comparative Example 1

[0067] This comparative example provides a method for preparing a MAPbBr3 perovskite film using the traditional spin-coating method, specifically:

[0068] The quartz substrate is ultrasonically cleaned with ethanol for 15 minutes and then treated with oxygen plasma for 20 minutes. 16.8 mg of MABr and 55 mg of PbBr2 powders are dissolved in a mixed solvent (DMF / DMSO = 1:1), and stirred at 70 °C for 2 hours. The fully reacted solution is filtered through a sieve to remove impurities. Then, 90 μL of the precursor solution is spun at 3500 rpm for 60 seconds. Finally, the film is annealed at 70 - 90 °C for 10 minutes to obtain the MAPbBr3 perovskite film.

[0069] Embodiments 8 - 19

[0070] These embodiments use the same preparation method as in embodiment 1 to prepare two-dimensional large-area organic-inorganic hybrid perovskites. The differences are shown in Table 1.

[0071] Table 1 Raw Material Table for Embodiments 8 - 19

[0072]

[0073]

[0074] The two-dimensional large-area organic-inorganic hybrid perovskites prepared by Examples 8-19 all have the properties of large size, high quality, and good uniformity. The photodetector containing the hybrid perovskites prepared by Examples 8-19 of the present invention has excellent performance and fast response time.

[0075] Results and analysis:

[0076] Figure 1 Schematic diagram of the device used for the self-limiting chemical vapor deposition reaction of the present invention. When heated to a certain temperature in an Ar gas atmosphere, PbBr2 and HABr are decomposed into Pb 2+ / Br - and HA + / Br - , HA + The ions are adsorbed on the surface of PbBr2, thereby changing the growth rate of each crystal face and preparing a two-dimensional large-area PbBr2.

[0077] The surface morphology of the large-area PbBr2 prepared in Example 2-5 was characterized by an optical microscope. Figure 2 , Figure 3 , Figure 4 and Figure 5 . Under normal pressure, PbBr2 prepared by self-limiting chemical vapor deposition presents a regular square shape on mica and silicon oxide substrates at a distance of 16 cm from T1, with a maximum area of 230 microns. When further away from T1 by 14 cm, it grows into an irregular shape on the mica substrate, with a maximum size of sub-millimeter level. Under low pressure conditions, with sufficient source supply, PbBr2 spreads evenly on the entire substrate, forming a dense film of 1.5 cm × 1.5 cm.

[0078] The large area PbBr2 prepared in Example 2 was tested using a Raman spectrometer. The results are shown in Figure 6 and Figure 7 The results show that the Raman peak of the prepared PbBr2 is at 34cm -1 and 106cm -1 , PbBr2 at 106cm -1 The Raman peak scan is uniform, indicating that the prepared large-area PbBr2 has good crystallinity and a uniform surface.

[0079] The large-area PbBr2 sheet prepared in Example 2 was characterized by scanning electron microscopy. Figure 8 The results showed that the surface of PbBr2 was smooth and the material was dense, indicating that the prepared large-area PbBr2 template was of high quality.

[0080] Elemental analysis (carbon, nitrogen, lead, and bromine) of the large-area PbBr2 template prepared in Example 2 was performed using energy-dispersive X-ray spectroscopy in a scanning electron microscope. The results are shown in Figure 9 . The results show that trace amounts of carbon and nitrogen elements are present in PbBr2, which are brought by HA + ions adsorbed on the surface of PbBr2.

[0081] Figure 10 Figure is a schematic diagram of the device for converting large-area PbBr2 into MAPbBr3 perovskite. Under an Ar gas atmosphere, MABr is heated to a certain temperature and decomposed into MA + / Br - , MA + ions are intercalated into the PbBr6 interstitial sites, and Br - ions are redistributed to obtain MAPbBr3 perovskite.

[0082] The surface morphology of the large-area MAPbBr3 prepared in Example 1 was characterized using an optical microscope. The results are shown in Figure 11 and 12 . The results show that compared with Figure 2 and Figure 3 the unconverted PbBr2 template, MAPbBr3 maintains the original morphology of PbBr2 and has a clean surface.

[0083] The phase characterization of PbBr2 and MAPbBr3 prepared in Examples 1 and 2 was performed using an X-ray diffractometer. The results are shown in Figure 13 . The results show that for PbBr2, the (006) and (008) crystal planes are perpendicular to the c-axis, and there are also (121), (103), and (202) crystal planes. After reaction with MABr, the (002), (003), (111), and (210) crystal planes of MAPbBr3 were observed.

[0084] The optical absorption and luminescence properties of the MAPbBr3 prepared in Example 1 were characterized using a Raman spectrometer and a UV-visible absorption spectrometer. The results are shown in Figure 14 . The results show that the converted MAPbBr3 has obvious absorption of light with wavelengths of 530 - 550 nm, which corresponds to its photoluminescence spectrum. In addition, the converted MAPbBr3 has very strong photoluminescence properties at room temperature, indicating its high quality.

[0085] The MAPbBr3 perovskite materials prepared by the conversion method and the spin-coating method in Example 1 and Comparative Example 1 and the MAPbBr3 devices prepared by Example 7 were placed in air at room temperature of 23 °C and humidity of 30% RH, and the changes in the morphology, optical luminescence properties, and device responsivity of the perovskite materials over time were observed.

[0086] The optoelectronic properties of the MAPbBr3 device in Example 7 were characterized using a probe station and a semiconductor analyzer. The results are shown in Figure 15 , Figure 16 , Figure 17 and Figure 18 . The results show that the MAPbBr3 lateral device converted in Example 7 has an obvious optical response to the 532 nm laser and exhibits a fast optical response under the optical pulse of 50 Hz.

[0087] The stability of the MAPbBr3 prepared by the conversion method and the spin-coating method in Example 1 and Comparative Example 1 was characterized using an optical microscope, a Raman spectrometer, a probe station, and a semiconductor analyzer. The results are shown in Figure 19 , Figure 20 , Figure 21 and Figure 22 . The results show that in the atmospheric environment, the morphology and photoluminescence intensity of the MAPbBr3 prepared by the conversion method in Example 1 did not change within 180 days, while the MAPbBr3 prepared by the spin-coating method in Comparative Example 1 began to decompose within 12 hours, a large amount of water droplets appeared on the material surface after 2 days of placement, and the photoluminescence intensity also decreased sharply. After 3 days, there was basically no luminescence property. Among the prepared devices, in the atmospheric environment, the responsivity of the MAPbBr3 device prepared by the conversion method in Example 1 hardly changed within 180 days, the performance of the MAPbBr3 device prepared by the spin-coating method in Comparative Example 1 decreased after 2 days of placement, and the device performance decreased sharply after 3 days. The performance shown was brought by the degraded material. The stability of the MAPbBr3 converted in Example 1 may be due to the hydrophobic effect of HA + adsorbed on the surface during self-limiting chemical vapor deposition.

[0088] It should be noted that in the above embodiments, the device used in Step 1 specifically includes: a tube furnace 1, a heating jacket 2, a quartz tube 3 with both ends open, a quartz tube 4 with only one end open, an Al2O3 porcelain boat, and a quartz U-shaped groove; wherein, the tube furnace 1 and the heating jacket 2 are sequentially arranged on the outer wall of the quartz tube 3 with both ends open for heating different positions of the quartz tube 3 with both ends open; inside the quartz tube 3 with both ends open, along the direction of the protective atmosphere entering, the Al2O3 porcelain boat and the quartz tube 4 with only one end open are sequentially arranged at intervals, and the open end of the quartz tube 4 with only one end open faces the setting direction of the Al2O3 porcelain boat, and the Al2O3 porcelain boat is located at the heating center T1 of the tube furnace 1, and the closed end of the quartz tube 4 with only one end open is located at the heating center T2 of the heating jacket 2. The quartz tube 4 with only one end open is placed in the quartz U-shaped groove, and the substrate is erected on the top of the quartz U-shaped groove; the Al2O3 porcelain boat is provided with a halide precursor powder, and the closed end of the quartz tube 4 with only one end open is provided with a surface passivator.

[0089] Specifically, when preparing large-area halides, the tube furnace 1 has a diameter of 30 mm and a length of 35 cm. The heating sleeve 2 has openings at both ends, a diameter of 30 mm, and a length of 10 cm. A quartz tube 3 with an opening at both ends, a diameter of 25 mm, and a length of 100 cm passes through the tube furnace. The heating sleeve 2 is sleeved on the downstream of the quartz tube 3 with openings at both ends and is placed outside the tube furnace. The halide precursor powder is placed in an Al2O3 porcelain boat and placed at the heating center position T1 of the tube furnace. The surface passivation agent powder is placed in a quartz tube 4 with only one end open and one end closed. The open end is adjacent to the Al2O3 porcelain boat of the halide precursor powder, and the closed end is placed at the center position T2 of the heating sleeve. The quartz tube 4 with only one end open containing the surface passivation agent powder is placed in a quartz U-shaped groove with a length of 12 cm. Multiple substrates are placed flat in the quartz U-shaped groove in sequence, facilitating the deposition and growth of materials on them. The substrates are arranged between T1 and T2 and are 12 cm, 14 cm, and 16 cm away from T1 respectively. The gas used as the carrier gas and the protective gas is introduced through the upstream inlet of the quartz tube 3. The evaporated halides volatilize along the gas direction to the downstream of the quartz tube 3. At the same time, the gas changes the evaporated passivation agent gas in the opposite direction, and the passivation agent gas also volatilizes to the downstream of the quartz tube 3. The halides nucleate and grow at the temperature between T1 and T2, and the passivation agent also adsorbs on different surfaces of the halides here, changing the surface energy of different surfaces of the halides. The surface with a higher surface energy continuously adsorbs the source of the growing halides along the direction perpendicular to its surface for growth, and the growth result exposes the surface with the lowest surface energy.

[0090] In the above embodiment, when converting the prepared halides into perovskite in step 2, the device used is as follows: the tube furnace 1 has a diameter of 30 mm and a length of 35 cm. A quartz tube 3 with an opening at both ends, a diameter of 25 mm, and a length of 100 cm passes through the tube furnace. At this time, there is no need to set up a heating sleeve again. The organic salt containing CH3NH3 + or CH(NH2)2 + is placed in a quartz U-shaped groove with a length of 10 cm and placed at the heating center position of the tube furnace, and the heating temperature is set to T3. The substrate with the prepared halide template is placed flat in the quartz U-shaped groove and is 5 cm away from the center of the tube furnace.

[0091] It is easy for those skilled in the art to understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing two-dimensional large-area organic-inorganic hybrid perovskite, characterized in that, The method includes the following steps: (1) Heat the halide precursor powder and the surface passivator to different temperatures respectively, so that the surface passivator is adsorbed on the surface of the reaction source, thereby passivating the surface with the most adsorbed surface passivator; use chemical vapor deposition to grow a two-dimensional halide template on the substrate; the surface passivator is one of (RNH3)X, RNH4, R2NH2X, R3NHX and R4NX, where R is an alkyl group with 4-18 carbon atoms, and X is Cl, Br or I; (2) By means of a gas-phase conversion method, using an organic salt containing CH3NH3 + or CH(NH2)2 + for hybridization to convert a two-dimensional halide template into an organic-inorganic hybrid perovskite; The device used in the method includes a tube furnace (1), a heating jacket (2), a quartz tube with both ends open (3), a quartz tube with only one end open (4), an Al2O3 porcelain boat and a quartz U-shaped groove; The tube furnace (1) and the heating jacket (2) are sequentially arranged on the outer wall of the quartz tube with both ends open (3) for heating different positions of the quartz tube with both ends open (3); along the direction of the protective atmosphere entering inside the quartz tube with both ends open (3), the Al2O3 porcelain boat and the quartz tube with only one end open (4) are sequentially arranged at intervals, and the open end of the quartz tube with only one end open (4) faces the setting direction of the Al2O3 porcelain boat, and the Al2O3 porcelain boat is at the heating center T1 of the tube furnace (1), and the closed end of the quartz tube with only one end open (4) is at the heating center T2 of the heating jacket (2). The quartz tube with only one end open (4) is placed in the quartz U-shaped groove, and the substrate is mounted on the top of the quartz U-shaped groove; The halide precursor powder is arranged in the Al2O3 porcelain boat, and the surface passivator is arranged at the closed end of the quartz tube with only one end open (4).

2. The method according to claim 1, wherein The surface passivator is one of butylamine hydrochloride, butylamine hydrobromide, butylamine hydroiodide, pentylamine hydrochloride, pentylamine hydrobromide, pentylamine hydroiodide, hexylamine hydrochloride, hexylamine hydrobromide, hexylamine hydroiodide, butylamine, pentylamine or hexylamine.

3. The method according to claim 1, wherein The organic salt is one of methylamine hydrochloride, methylamine hydrobromide, methylamine hydroiodide, methyl ether hydrochloride, methyl ether hydrobromide, or methyl ether hydroiodide.

4. The method according to claim 1, wherein In the step (1), heating the halide precursor powder and the surface passivator to different temperatures respectively means: heating the halide precursor powder to 250-450 °C, heating the surface passivator to 150-250 °C, and the heating time is 10 minutes - 5 hours.

5. The method according to any one of claims 1 to 4, characterized in that, The halide precursor powder is one of SnCl2, SnBr2, SnI2, PbCl2, PbBr2, PbI2, CuCl2, CuBr2, MnCl2, MnBr2, MnI2, CdCl2, CdBr2 and CdI2.

6. The method according to claim 1, characterized in that, The gas-phase conversion method is: under the conditions of no oxygen and less than 1%-10% of atmospheric pressure, the heating temperature is 70-160 °C, and the reaction time is 15 minutes - 3 hours.

7. A two-dimensional large-area organic-inorganic hybrid perovskite prepared by the method according to any one of claims 1-6, characterized in that, The single crystal wafer area of the two-dimensional large-area organic-inorganic hybrid perovskite can reach up to 500 microns at most, and the film area is 1.5 cm × 1.5 cm.

8. The two-dimensional large-area organic-inorganic hybrid perovskite according to claim 7, wherein, The two-dimensional large-area organic-inorganic hybrid perovskite is placed in the atmosphere for 180 days, and there is no degradation on the surface and no decline in the luminescence characteristics.

9. A photodetector, characterized in that, The photodetector includes the two-dimensional large-area organic-inorganic hybrid perovskite as described in claim 7 or 8; the response time of the photodetector is less than 10 μs; the photodetector is placed in the atmospheric condition for 180 days, and its light detection performance does not degrade.

10. An apparatus for preparing the two-dimensional large-area organic-inorganic hybrid perovskite according to claim 7 or 8, characterized in that, The device includes: a tube furnace (1), a heating jacket (2), a quartz tube with both ends open (3), a quartz tube with only one end open (4), an Al2O3 porcelain boat, and a quartz U-shaped groove; Wherein, the tube furnace (1) and the heating jacket (2) are sequentially arranged on the outer wall of the quartz tube with both ends open (3) for heating different positions of the quartz tube with both ends open (3); inside the quartz tube with both ends open (3) along the direction of the protective atmosphere entering, the Al2O3 porcelain boat and the quartz tube with only one end open (4) are sequentially arranged at intervals, and the open end of the quartz tube with only one end open (4) faces the setting direction of the Al2O3 porcelain boat, and the Al2O3 porcelain boat is located at the heating center T1 of the tube furnace (1), the closed end of the quartz tube with only one end open (4) is located at the heating center T2 of the heating jacket (2), the quartz tube with only one end open (4) is placed in the quartz U-shaped groove, and the substrate is mounted on the top of the quartz U-shaped groove; The Al2O3 porcelain boat is provided with a halide precursor powder, and the closed end of the quartz tube with only one end open (4) is provided with a surface passivator.

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