A preparation method of guanidino lead halide perovskite single crystal and its application in photodetectors

Abstract

A preparation method of a guanidine lead halide perovskite single crystal and its application in a photodetector, which relates to a preparation method of a perovskite single crystal and its application. The present invention uses aminoguanidine cation (AG + ) as an organic cation, a new type of perovskite single crystal material with a suitable single crystal optical band gap and a high light absorption coefficient is obtained, and it is used in the field of visible light detection. Method: 1. Prepare a precursor solution; 2. Prepare a perovskite single crystal; 3. Clean, dry and polish. A guanidino lead halide perovskite single crystal is used to prepare a photodetector. The guanidino lead halide perovskite single crystal prepared by the present invention has excellent light absorption performance, high carrier mobility and carrier lifetime, good crystallinity and high humidity and temperature stability, and good detector photoelectric response performance; in terms of preparation technology, the manufacturing cost is low, the production process is simple, the temperature required for cooling and crystallization is low, the energy consumption is low, and the requirements for experimental conditions are low.

Description

Technical Field

[0001] The invention relates to a preparation method of a perovskite single crystal and application thereof. Background Art

[0002] Photodetectors are essential components of modern imaging and communication systems, playing an increasingly crucial role in modern industrial production, basic scientific research, space development, ocean exploration, military and defense, environmental protection, medical diagnostics, transportation, and other fields. For example, ultraviolet photodetectors are used for ozone sensing and flame sensing; visible photodetectors are used for biosensing, video imaging, and transducer communications; infrared photodetectors are used for infrared night vision; and terahertz photodetectors are used for security inspections at customs, airports, and other specialized locations. Therefore, further research on photodetectors is of great significance. Semiconductor materials are crucial for photodetectors, absorbing incident photons and generating photogenerated carriers. Under the influence of an internal or external electric field, electrodes collect these photogenerated carriers to generate a current signal. To achieve high-performance photodetectors with high sensitivity and fast response, semiconductor materials must possess low defect state density and high carrier mobility to enable efficient charge collection.

[0003] Organic-inorganic lead halide perovskite materials (such as MAPbI3 and FAPbI3) have attracted considerable attention in the field of photodetection due to their advantages, including tunable band gaps and long carrier diffusion lengths. However, three-dimensional (3D) perovskite materials exhibit severe spontaneous phase transitions at room temperature and are unstable in humid environments, hindering their practical application in atmospheric environments. Low-dimensional perovskite materials (including two-dimensional (2D), one-dimensional (1D), and zero-dimensional (0D) structures) have inorganic backbones separated by organic cations, which excel in suppressing ion migration and improving humidity stability. Low-dimensional perovskite single crystal detectors prepared with monoamine ions as organic cations have reduced carrier mobility due to the organic groups between the long lead halide chains, which restricts interlayer charge transfer. Replacing the monoamine ions with diamine ions reduces the distance between the long lead halide chains and improves charge transport, as both ends of the diamine ions are hydrogen-bonded to the inorganic layers. However, the low solubility of diamine ions increases the difficulty and cost of fabrication. Guanidine ions have better thermodynamic stability and stronger hydrogen bonding ability and have been shown to be an ideal substitute for monoammonium cations. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a method for preparing a guanidinium lead halide perovskite single crystal and its application in a photodetector.

[0005] A method for preparing a guanidino lead halide perovskite single crystal is specifically completed by the following steps:

[0006] 1. Preparation of precursor solution:

[0007] Mix hydroiodic acid (HI) and hypophosphorous acid (H3PO2) to obtain a mixed solution of HI and H3PO2; add appropriate amounts of lead oxide and aminoguanidine hydrochloride (AGCl) to the mixed solution, and heat and stir on a hot plate to obtain a light yellow precursor solution;

[0008] 2. Preparation of perovskite single crystals:

[0009] The pale yellow precursor solution was placed in a constant temperature furnace with the same temperature as the hot stage, and the constant temperature furnace was then heated to 100°C, kept at 100°C, and then cooled to room temperature to obtain a perovskite single crystal;

[0010] 3. Cleaning, drying and polishing:

[0011] The perovskite single crystal is taken out, washed several times, and then placed in a drying oven to dry. The surface of the single crystal is then polished to obtain a guanidinium lead halide perovskite AGPbI3 single crystal with a bright surface.

[0012] A guanidine lead halide perovskite single crystal is used to prepare a photodetector, which is completed according to the following steps:

[0013] 1. Fix one side of the guanidino lead halide perovskite single crystal on a mask with an interdigitated electrode pattern;

[0014] 2. Depositing gold on one side of the guanidino lead halide perovskite single crystal fixed on the mask plate to obtain an interdigitated electrode, which is a photodetector based on a guanidino lead halide perovskite single crystal.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The guanidinium lead halide perovskite single crystal prepared by the present invention has excellent light absorption performance, good crystallinity and high humidity and temperature stability, and the detector has good photoelectric response and excellent weak signal detection capability; in terms of preparation, the manufacturing cost and difficulty are low, the production process is simple, the temperature required for cooling and crystallization is low, the energy consumption is low, and the requirements for experimental conditions are low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a photograph of the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1;

[0018] Figure 2 The crystal structure diagram of the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 in the a-axis direction and the c-axis direction;

[0019] Figure 3 XRD diffraction patterns of the guanidino lead halide perovskite AGPbI3 single crystal, powder, and theoretical simulation prepared in Example 1;

[0020] Figure 4 This is the light absorption graph of the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1;

[0021] Figure 5 IV curve of a photodetector based on a guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 in a dark environment and with an external bias voltage ranging from -5V to 5V;

[0022] Figure 6 IV curves of a photodetector based on a guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 under different light intensities and external bias voltages ranging from -40 V to 40 V;

[0023] Figure 7 A comparison chart of the response current of a photodetector based on a guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 under different light intensities and external bias conditions;

[0024] Figure 8 A comparison chart of the response rates of a photodetector based on a guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 under different light intensities and external bias conditions;

[0025] Figure 9 The photodetector based on a guanidine lead halide perovskite AGPbI3 single crystal prepared in Example 1 was tested under different external bias voltages and a light intensity of 43.6 mW / cm 2 IT curve under certain conditions. DETAILED DESCRIPTION

[0026] Specific embodiment 1: This embodiment provides a method for preparing a guanidinium lead halide perovskite single crystal, which is specifically completed by the following steps:

[0027] 1. Prepare precursor solution:

[0028] Mixing hydroiodic acid and hypophosphorous acid to obtain a mixed solution of HI and H3PO2; adding lead oxide and aminoguanidine hydrochloride to the mixed solution, heating and stirring on a hot plate for a period of time to obtain a light yellow precursor solution;

[0029] 2. Preparation of perovskite single crystals:

[0030] The pale yellow precursor solution is placed in a constant temperature furnace with the same temperature as the hot stage, and then the constant temperature furnace is raised to 100°C, kept at 100°C for a period of time, and then slowly cooled to room temperature to obtain a perovskite single crystal;

[0031] 3. Cleaning, drying and polishing:

[0032] The perovskite single crystal is taken out, washed several times, and then placed in a drying oven to dry. The surface of the single crystal is then polished to obtain a guanidinium lead halide perovskite AGPbI3 single crystal with a bright surface.

[0033] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the mass fraction of the hydroiodic acid in step 1 is 57%; the mass fraction of the hypophosphorous acid in step 1 is 50%; and the volume ratio of the hydroiodic acid to the hypophosphorous acid in step 1 is (3-5):1. The other steps are the same as specific embodiment 1.

[0034] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that the molar ratio of lead oxide to aminoguanidine hydrochloride in step 1 is 1:2. The other steps are the same as those in specific embodiment 1 or 2.

[0035] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the molar concentration of lead oxide in the precursor solution in step 1 is 0.05 mol / L to 1 mol / L. The other steps are the same as those in specific embodiments 1 to 3.

[0036] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the heating and stirring temperature in step 1 is 50°C to 90°C, the heating and stirring time is 60 minutes to 120 minutes, and the heating and stirring speed is 1000 rpm to 3000 rpm. The other steps are the same as specific embodiments 1 to 4.

[0037] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that the holding time at 100° C. in step 2 is 60 min to 360 min. The other steps are the same as those in specific embodiments 1 to 5.

[0038] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that the heating rate in step 2 is 0.3°C / h; the cooling rate in step 2 is 0.2°C / h to 3°C / h. The other steps are the same as specific embodiments 1 to 6.

[0039] Specific Embodiment 8: This embodiment differs from Specific Embodiments 1 to 7 in that: in step 3, the perovskite single crystal is cleaned three times with isopropyl alcohol or chlorobenzene; the drying temperature in step 3 is 40°C to 60°C, and the drying time is 1 hour; and the surface of the single crystal is polished with 10,000-grit fine sandpaper in step 3. The other steps are the same as in Specific Embodiments 1 to 7.

[0040] Specific embodiment 9: This embodiment is a guanidine lead halide perovskite single crystal used to prepare a photodetector, which is specifically completed by the following steps:

[0041] 1. Fixing one side of a guanidinium lead halide perovskite single crystal on a mask having an interdigitated electrode pattern;

[0042] The area of ​​the interdigitated electrodes described in step 1 is 1.2×10 -3 cm 2 ;

[0043] 2. Depositing gold on one side of a guanidino lead halide perovskite single crystal to which a mask is fixed to obtain an interdigitated electrode, i.e., a photodetector based on a guanidino lead halide perovskite single crystal;

[0044] Specific embodiment 10: This embodiment differs from the application embodiment 1 in that the thickness of the interdigital electrodes in step 2 is 80-100 nm.

[0045] The following examples are used to verify the beneficial effects of the present invention:

[0046] Example 1: A method for preparing a guanidino lead halide perovskite single crystal is specifically completed by the following steps:

[0047] 1. Preparation of precursor solution:

[0048] Mixing hydroiodic acid and hypophosphorous acid to obtain a mixed solution of HI and H3PO2; adding lead oxide and aminoguanidine hydrochloride to the mixed solution, heating and stirring on a hot plate at 80°C for 60 minutes at a heating and stirring speed of 1500 rpm to obtain a light yellow precursor solution;

[0049] The mass fraction of the hydroiodic acid described in step 1 is 57%;

[0050] The mass fraction of the hypophosphorous acid described in step 1 is 50%;

[0051] The volume ratio of hydroiodic acid to hypophosphorous acid described in step 1 is 5:1;

[0052] The molar ratio of lead oxide to aminoguanidine hydrochloride in step 1 is 1:2;

[0053] The concentration of lead oxide in the precursor solution described in step 1 is 0.067 mol / L;

[0054] 2. Preparation of perovskite single crystals:

[0055] The pale yellow precursor solution was placed in a constant temperature furnace at 80°C, and then the temperature of the constant temperature furnace was raised to 100°C, kept at 100°C for 360 minutes, and then slowly cooled to room temperature to obtain a perovskite single crystal;

[0056] The heating rate in step 2 is 0.3°C / h;

[0057] The cooling rate in step 2 is 0.2°C / h;

[0058] 3. Cleaning, drying and polishing:

[0059] The perovskite single crystal was taken out, rinsed repeatedly with isopropyl alcohol three times, placed in a drying oven at 60°C for 60 minutes, and then polished with 10,000 mesh fine sandpaper to obtain a guanidine lead halide perovskite AGPbI3 single crystal with a bright surface.

[0060] Table 1 shows the crystal structure data of the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1;

[0061]

[0062] Example 2: A method for preparing a guanidino lead halide perovskite single crystal is specifically completed by the following steps:

[0063] 1. Preparation of precursor solution:

[0064] Mixing hydroiodic acid and hypophosphorous acid to obtain a mixed solution of HI and H3PO2; adding lead oxide and aminoguanidine hydrochloride to the mixed solution, heating and stirring on a hot plate at 80°C for 120 minutes at a heating and stirring speed of 1000 r / min to obtain a light yellow precursor solution;

[0065] The mass fraction of the hydroiodic acid described in step 1 is 57%;

[0066] The mass fraction of the hypophosphorous acid described in step 1 is 50%;

[0067] The volume ratio of hydroiodic acid to hypophosphorous acid described in step 1 is 5:1;

[0068] The molar ratio of lead oxide to aminoguanidine hydrochloride in step 1 is 1:2;

[0069] The concentration of lead oxide in the precursor solution described in step 1 is 0.067 mol / L;

[0070] 2. Preparation of perovskite single crystals:

[0071] The pale yellow precursor solution was placed in a constant temperature furnace at 80°C, and then the temperature of the constant temperature furnace was raised to 100°C, kept at 100°C for 360 minutes, and then slowly cooled to room temperature to obtain a perovskite single crystal;

[0072] The heating rate in step 2 is 0.3°C / h;

[0073] The cooling rate in step 2 is 3°C / h;

[0074] 3. Cleaning, drying and polishing:

[0075] The perovskite single crystal was taken out, rinsed repeatedly with chlorobenzene three times, placed in a drying oven at 60°C for 60 minutes, and then polished with 10,000 mesh fine sandpaper to obtain a guanidine lead halide perovskite AGPbI3 single crystal with a bright surface.

[0076] Example 3: A method for preparing a guanidino lead halide perovskite single crystal is specifically completed by the following steps:

[0077] 1. Preparation of precursor solution:

[0078] Mixing hydroiodic acid and hypophosphorous acid to obtain a mixed solution of HI and H3PO2; adding lead oxide and aminoguanidine hydrochloride to the mixed solution, heating and stirring on a hot plate at 80°C for 120 minutes at a heating and stirring speed of 1500 rpm to obtain a light yellow precursor solution;

[0079] The mass fraction of the hydroiodic acid described in step 1 is 57%;

[0080] The mass fraction of the hypophosphorous acid described in step 1 is 50%;

[0081] The volume ratio of hydroiodic acid to hypophosphorous acid described in step 1 is 5:1;

[0082] The molar ratio of lead oxide to aminoguanidine hydrochloride in step 1 is 1:2;

[0083] The concentration of lead oxide in the precursor solution described in step 1 is 0.4 mol / L;

[0084] 2. Preparation of perovskite single crystals:

[0085] The pale yellow precursor solution was placed in a constant temperature furnace at 80°C, and then the temperature of the constant temperature furnace was raised to 100°C, kept at 100°C for 360 minutes, and then slowly cooled to room temperature to obtain a perovskite single crystal;

[0086] The heating rate in step 2 is 0.3°C / h;

[0087] The cooling rate in step 2 is 1°C / h;

[0088] 3. Cleaning, drying and polishing:

[0089] The perovskite single crystal was taken out, rinsed repeatedly with chlorobenzene three times, placed in a drying oven at 60°C for 60 minutes, and then polished with 10,000 mesh fine sandpaper to obtain a guanidine lead halide perovskite AGPbI3 single crystal with a bright surface.

[0090] Example 4: A method for preparing a guanidino lead halide perovskite single crystal is specifically completed by the following steps:

[0091] 1. Preparation of precursor solution:

[0092] Mixing hydroiodic acid and hypophosphorous acid to obtain a mixed solution of HI and H3PO2; adding lead oxide and aminoguanidine hydrochloride to the mixed solution, heating and stirring on a hot plate at 80°C for 120 minutes at a heating and stirring speed of 1500 rpm to obtain a light yellow precursor solution;

[0093] The mass fraction of the hydroiodic acid described in step 1 is 57%;

[0094] The mass fraction of the hypophosphorous acid described in step 1 is 50%;

[0095] The volume ratio of hydroiodic acid and hypophosphorous acid described in step 1 is 3:1;

[0096] The molar ratio of lead oxide to aminoguanidine hydrochloride in step 1 is 1:2;

[0097] The concentration of lead oxide in the precursor solution described in step 1 is 0.4 mol / L;

[0098] 2. Preparation of perovskite single crystals:

[0099] The pale yellow precursor solution was placed in a constant temperature furnace at 80°C, and then the temperature of the constant temperature furnace was raised to 100°C, kept at 100°C for 60 minutes, and then slowly cooled to room temperature to obtain a perovskite single crystal;

[0100] The heating rate in step 2 is 0.3°C / h;

[0101] The cooling rate in step 2 is 1°C / h;

[0102] 3. Cleaning, drying and polishing:

[0103] The perovskite single crystal was taken out, rinsed repeatedly with chlorobenzene three times, placed in a drying oven at 60°C for 60 minutes, and then polished with 10,000 mesh fine sandpaper to obtain a guanidine lead halide perovskite AGPbI3 single crystal with a bright surface.

[0104] Example 5: A method for preparing a guanidino lead halide perovskite single crystal is specifically completed by the following steps:

[0105] 1. Preparation of precursor solution:

[0106] Mixing hydroiodic acid and hypophosphorous acid to obtain a mixed solution of HI and H3PO2; adding lead oxide (PbO) and aminoguanidine hydrochloride to the mixed solution, heating and stirring on a hot plate at 80°C for 120 minutes at a heating and stirring speed of 1500 r / min to obtain a light yellow precursor solution;

[0107] The mass fraction of the hydroiodic acid described in step 1 is 57%;

[0108] The mass fraction of the hypophosphorous acid described in step 1 is 50%;

[0109] The volume ratio of hydroiodic acid and hypophosphorous acid described in step 1 is 3:1;

[0110] The molar ratio of lead oxide to aminoguanidine hydrochloride in step 1 is 1:2;

[0111] The concentration of lead oxide in the precursor solution described in step 1 is 0.2 mol / L;

[0112] 2. Preparation of perovskite single crystals:

[0113] The pale yellow precursor solution was placed in a constant temperature furnace at 80°C, and then the temperature of the constant temperature furnace was raised to 100°C, kept at 100°C for 360 minutes, and then slowly cooled to room temperature to obtain a perovskite single crystal;

[0114] The heating rate in step 2 is 0.3°C / h;

[0115] The cooling rate in step 2 is 0.2°C / h;

[0116] 3. Cleaning, drying and polishing:

[0117] The perovskite single crystal was taken out, rinsed repeatedly with chlorobenzene three times, placed in a drying oven at 60°C and dried for 60 minutes, and then polished with 10,000 mesh fine sandpaper to obtain a guanidine lead halide perovskite AGPbI3 single crystal with a bright surface.

[0118] Application Example 1: The preparation of a photodetector using the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 is specifically completed by the following steps:

[0119] 1. Fixing one side of a guanidinium lead halide perovskite single crystal on a mask having an interdigitated electrode pattern;

[0120] The area of ​​the interdigitated electrodes described in step 1 is 1.2×10 -3 cm 2 ;

[0121] 2. Depositing 80 nm of gold on one side of a guanidino lead halide perovskite single crystal to which a mask is fixed to obtain an interdigitated electrode, i.e., a photodetector based on a guanidino lead halide perovskite single crystal;

[0122] Application Example 2: The preparation of a photodetector using the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 2 is specifically completed by the following steps:

[0123] 1. Fixing one side of a guanidinium lead halide perovskite single crystal on a mask having an interdigitated electrode pattern;

[0124] The area of ​​the interdigitated electrodes described in step 1 is 1.2×10 -3 cm 2 ;

[0125] 2. Depositing 100 nm of gold on one side of a guanidino lead halide perovskite single crystal to which a mask is fixed to obtain an interdigitated electrode, i.e., a photodetector based on a guanidino lead halide perovskite single crystal;

[0126] Application Example 3: The preparation of a photodetector using the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 3 is specifically completed by the following steps:

[0127] 1. Fixing one side of a guanidinium lead halide perovskite single crystal on a mask having an interdigitated electrode pattern;

[0128] The area of ​​the interdigitated electrodes described in step 1 is 1.2×10 -3 cm 2 ;

[0129] 2. Depositing 85 nm of gold on one side of a guanidino lead halide perovskite single crystal to which a mask is fixed to obtain an interdigitated electrode, i.e., a photodetector based on a guanidino lead halide perovskite single crystal;

[0130] Application Example 4: The preparation of a photodetector using the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 4 is specifically completed by the following steps:

[0131] 1. Fixing one side of a guanidinium lead halide perovskite single crystal on a mask having an interdigitated electrode pattern;

[0132] The area of ​​the interdigitated electrodes described in step 1 is 1.2×10 -3 cm 2 ;

[0133] 2. Depositing 100 nm of gold on one side of a guanidino lead halide perovskite single crystal to which a mask is fixed to obtain an interdigitated electrode, i.e., a photodetector based on a guanidino lead halide perovskite single crystal;

[0134] Application Example 5: The preparation of a photodetector using the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 5 is specifically completed by the following steps:

[0135] 1. Fixing one side of a guanidinium lead halide perovskite single crystal on a mask having an interdigitated electrode pattern;

[0136] The area of ​​the interdigitated electrodes described in step 1 is 1.2×10 -3 cm 2 ;

[0137] 2. Depositing 90 nm of gold on one side of a guanidino lead halide perovskite single crystal to which a mask is fixed to obtain an interdigitated electrode, i.e., a photodetector based on a guanidino lead halide perovskite single crystal;

[0138] Figure 1 This is a photograph of the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1;

[0139] from Figure 1 It can be seen that the single crystal size is 7×3×2mm 3 .

[0140] Figure 2 The crystal structure diagram of the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 in the a-axis direction and the c-axis direction;

[0141] from Figure 2 It can be seen that the adjacent inorganic octahedra of the prepared AGPbI3 single crystal are connected by sharing faces and present a chain-like distribution.

[0142] Figure 3 XRD diffraction patterns of the guanidino lead halide perovskite AGPbI3 single crystal, powder, and theoretical simulation prepared in Example 1;

[0143] from Figure 3 It can be seen that the XRD diffraction pattern of AGPbI3 single crystal has sharp diffraction peaks, and the XRD diffraction peaks of the powder are basically consistent with those of theoretical simulation, indicating that the single crystal has high crystallinity and good growth orientation.

[0144] Figure 4 This is the light absorption graph of the guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1;

[0145] from Figure 4 It can be seen that single crystals have good optical properties.

[0146] Figure 5IV curve of a photodetector based on a guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 in a dark environment and with an external bias voltage ranging from -5V to 5V;

[0147] from Figure 5 It can be seen that the single crystal has a smaller dark current, indicating that the single crystal has a stronger detection capability for weak light.

[0148] Figure 6 IV curves of a photodetector based on a guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 under different light intensities and external bias voltages ranging from -40 V to 40 V;

[0149] from Figure 6 It can be seen that the AGPbI3 single crystal photodetector has a good photoelectric response. 2 The response current is 5.04×10 -8 A.

[0150] Figure 7 A comparison chart of the response current of a photodetector based on a guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 under different light intensities and external bias conditions;

[0151] from Figure 7 It can be seen that with the increase of light intensity and external bias, the response current also increases. This is because the increase of external bias leads to an acceleration of the carrier separation rate, and the increase of light intensity leads to an increase in the carrier concentration inside the single crystal, which leads to an increase in the response current.

[0152] Figure 8 A comparison chart of the response rates of a photodetector based on a guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 under different light intensities and external bias conditions;

[0153] from Figure 8 It can be seen that the response rate increases with the increase of light intensity and external bias voltage. When the external bias voltage is 40V and the light intensity is 3.8mW / cm 2 The response rate under these conditions is 3.6mA / W.

[0154] Figure 9 IT curves of a photodetector based on a guanidino lead halide perovskite AGPbI3 single crystal prepared in Example 1 under different external bias voltages and a light intensity of 43.6 mW / A;

[0155] from Figure 9It can be seen that the AGPbI3 single crystal photodetector has a good switching response. As the external bias voltage increases, the response current increases accordingly, which is consistent with the volt-ampere characteristic measurement results, indicating that the device has a good photoelectric response.

[0156] In summary, the above embodiments of the present invention disclose: (1) providing a method for preparing a novel perovskite single crystal material and a detector thereof, obtaining a novel perovskite single crystal material with high humidity and temperature stability, suitable optical band gap, and high light absorption coefficient by a cooling crystallization method, and successfully developing a device to realize its relevant application in perovskite photodetectors; (2) providing specific applications of the material.

[0157] The present invention has the following unforeseen benefits: (1) The novel perovskite single crystal material prepared using the present invention has excellent light absorption properties, high carrier mobility, long carrier lifetime, good crystallinity, high humidity and temperature stability, and the detector has a good photoelectric response. (2) In terms of preparation technology, the manufacturing cost is low, the production process is simple, the temperature required for cooling and crystallization is low, energy consumption is low, and the experimental conditions are low.

Claims

1. A method for preparing a guanidino lead halide perovskite single crystal, characterized in that The preparation method is specifically completed according to the following steps:

1. Preparation of precursor solution: Mixing hydroiodic acid and hypophosphorous acid to obtain a mixed solution of HI and H3PO2; adding lead oxide and aminoguanidine hydrochloride to the mixed solution, heating and stirring on a hot plate for a period of time to obtain a light yellow precursor solution; 2. Preparation of perovskite single crystals: The pale yellow precursor solution is placed in a constant temperature furnace with the same temperature as the hot stage, and then the constant temperature furnace is raised to 100°C, kept at 100°C for a period of time, and then slowly cooled to room temperature to obtain a perovskite single crystal; 3. Cleaning, drying and polishing: The perovskite single crystal is taken out, washed several times, and then placed in a drying oven to dry. The surface of the single crystal is then polished to obtain a guanidinium lead halide perovskite AGPbI3 single crystal with a bright surface.

2. The method for preparing a guanidino lead halide perovskite single crystal according to claim 1, wherein The mass fraction of the hydroiodic acid in step 1 is 57%; the mass fraction of the hypophosphorous acid in step 1 is 50%; the volume ratio of the hydroiodic acid to the hypophosphorous acid in step 1 is (3-5):

1.

3. The method for preparing a guanidino lead halide perovskite single crystal according to claim 1, wherein The molar ratio of lead oxide to aminoguanidine hydrochloride in step 1 is 1:

2.

4. The method for preparing a guanidino lead halide perovskite single crystal according to claim 1, wherein The concentration of lead oxide in the precursor solution in step 1 is 0.05 mol / L to 1 mol / L.

5. The method for preparing a guanidino lead halide perovskite single crystal according to claim 1, wherein The temperature of the heating and stirring in step 1 is 50-90° C., the time of the heating and stirring is 60 min-120 min, and the speed of the heating and stirring is 1000 r / min-3000 r / min.

6. The method for preparing a guanidino lead halide perovskite single crystal according to claim 1, wherein In step 2, the temperature is kept at 100° C. for 60 to 360 minutes.

7. The method for preparing a guanidino lead halide perovskite single crystal according to claim 1, wherein The heating rate in step 2 is 0.3°C / h; the cooling rate in step 2 is 0.2°C / h to 3°C / h.

8. The method for preparing a guanidino lead halide perovskite single crystal according to claim 1, wherein In step 3, the perovskite single crystal is cleaned three times using isopropyl alcohol or chlorobenzene; the drying temperature in step 3 is 40° C. to 60° C., and the drying time is 1 hour; in step 3, the surface of the single crystal is polished using fine sandpaper, and the fine sandpaper is 10,000 mesh.

9. Use of a guanidino lead halide perovskite single crystal prepared by the preparation method according to claim 1, characterized in that A guanidine lead halide perovskite single crystal is used to prepare a photodetector.

10. The use of a guanidino lead halide perovskite single crystal according to claim 9, characterized in that The preparation of a photodetector using a guanidine-based lead halide perovskite single crystal is specifically completed in the following steps:

1. Fixing one side of a guanidinium lead halide perovskite single crystal on a mask having an interdigitated electrode pattern; The area of ​​the interdigitated electrodes described in step 1 is 1.2×10 -3 cm 2 ; 2. Depositing gold on one side of a guanidino lead halide perovskite single crystal to which a mask is fixed to obtain an interdigitated electrode, i.e., a photodetector based on a guanidino lead halide perovskite single crystal; The thickness of the interdigitated electrodes in step 2 is 80-100 nm.

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