Preparation method of large-size rare earth doped phenethylamine lead bromide perovskite single crystal and perovskite single crystal

Abstract

The application relates to a large-size rare earth doped phenethylamine lead bromide perovskite monocrystal preparation method and perovskite monocrystal, and solves the technical problems that the preparation of the existing large-size rare earth doped two-dimensional perovskite monocrystal needs higher nucleation supersaturation, the preparation period is long, and part of the rare earth bromide is extremely easy to absorb moisture, thereby reducing the crystal quality. The large-size rare earth doped phenethylamine lead bromide perovskite monocrystal preparation method and perovskite monocrystal comprise the following steps: 1) weighing; phenethylamine hydrobromide, lead bromide and rare earth metal bromide are weighed and placed in a glass bottle; 2) obtaining a precursor solution; 3) obtaining a millimeter-level size crystal; 4) screening a seed crystal; and 5) seed crystal growth. In step 4), the open container B is placed at a preset temperature until the seed crystal continues to grow into a rare earth doped phenethylamine lead bromide perovskite monocrystal with a predetermined size, and the size can reach a centimeter level, which has an important supporting role in promoting the performance research of the rare earth doped two-dimensional perovskite monocrystal.

Description

TECHNICAL FIELD

[0001] The present application relates to a large-size rare earth doped phenethylamine lead bromide perovskite single crystal preparation method and perovskite single crystal. BACKGROUND

[0002] Perovskite materials have excellent photoelectric properties. Compared with three-dimensional perovskite, the alternating layered structure of organic macromolecule-inorganic layer of two-dimensional perovskite greatly enhances its stability and quantum confinement effect, and has been widely used. Compared with polycrystal and single crystal, two-dimensional perovskite has fewer grain boundary defects and better photoelectric properties.

[0003] Studies have shown that rare earth doping can adjust the band gap structure of perovskite, thereby adjusting the luminescent properties of perovskite. Due to the spontaneous exclusion of heteroions during the growth of large-size two-dimensional lead bromide perovskite single crystals, the doping of the crystals is more difficult than that of nanocrystals and micrometer crystals. Currently, there are studies on three-dimensional perovskite single crystals doped with rare earth and millimeter-size two-dimensional perovskite single crystals, such as Chinese patent CN114517332A, which discloses "an erbium-doped two-dimensional perovskite single crystal, a preparation method thereof, and a photoelectric detector". However, there is no report on the preparation method and performance of large-size rare earth doped two-dimensional perovskite single crystals. Although Chinese patent CN114395801A discloses "a preparation method of large-size, high-quality two-dimensional halide perovskite single crystals", experiments have shown that a higher nucleation supersaturation is required for a solution doped with rare earth, the seed crystal preparation period is as long as 2 weeks, and some rare earth bromides are extremely hygroscopic. Therefore, when the solvent evaporation method is used, the quality of the rare earth doped crystals is easily reduced due to moisture absorption during the growth process. Therefore, it is necessary to develop a new large-size rare earth doped perovskite preparation technical solution. SUMMARY

[0004] The purpose of the present application is to solve the technical problems of the existing large-size rare earth doped two-dimensional perovskite single crystal preparation, which requires a higher nucleation supersaturation and a long preparation period, and some rare earth bromides are extremely hygroscopic, resulting in reduced crystal quality, and to provide a large-size rare earth doped phenethylamine lead bromide perovskite single crystal preparation method and perovskite single crystal.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solution:

[0006] A large-size rare earth doped phenethylamine lead bromide perovskite single crystal preparation method, which is characterized by comprising the following steps:

[0007] 1) weighing;

[0008] Weigh phenethylamine hydrobromide, lead bromide, and rare earth metal bromide into a glass bottle;

[0009] 2) obtaining a precursor solution;

[0010] The N,N-dimethylformamide is added into a glass bottle, heated and stirred until completely dissolved to obtain a precursor solution;

[0011] 3) obtaining a millimeter-sized crystal;

[0012] The precursor solution is filtered and placed in an open container A, and then the open container A is sealed and connected with the outside through a small hole, and is placed in a preset temperature and low humidity environment for volatilization until a plurality of millimeter-sized or above crystals are precipitated; the low humidity environment refers to a relative humidity less than 40%.

[0013] 4) screening a seed crystal;

[0014] The solution in the open container A is filtered again and placed in an open container B; a piece of the seed crystal is taken from the plurality of independently grown millimeter-sized or above crystals, and is placed in the open container B; the open container B is sealed and heated until the seed crystal is partially dissolved, and then the heating is stopped and the open container B is slowly cooled to a preset temperature;

[0015] 5) seed crystal growth;

[0016] The open container B is placed in a preset temperature environment until the seed crystal continues to grow into a rare earth doped phenethylamine lead bromide perovskite single crystal with a predetermined size.

[0017] Further, in step 1), the molar numbers of the phenethylamine hydrobromide, lead bromide and rare earth metal bromide are n1, n2 and n3 respectively, and n1:n2:n3 = 2:1:x, x = 0.05-0.5.

[0018] Further, in step 1), the rare earth metal bromide is any one of NdBr3, CeBr3 and ErBr3.

[0019] Further, step 2) is specifically as follows:

[0020] After the N,N-dimethylformamide is added into the glass bottle, the heating table or the magnetic stirrer is used to heat to 30-85℃, and the stirring is performed until completely dissolved to obtain a precursor solution with a lead concentration of 1.3-1.5 mol / L.

[0021] Further, the preset temperature is room temperature, and the room temperature is 10-25℃.

[0022] Further, step 3) is specifically as follows:

[0023] The precursor solution is filtered by using a polytetrafluoroethylene filter head with a pore size of 0.45 microns or 0.22 microns, and the filtered solution is placed in an open container A, and then the open container A is sealed and a small hole with a diameter of 0.5-1 mm is punched, and is placed in a room temperature and low humidity environment for volatilization until a plurality of millimeter-sized or above crystals are precipitated.

[0024] Further, in step 3), the size is greater than or equal to 2 mm.

[0025] Further, it further comprises step 6):

[0026] The rare earth doped phenethylamine lead bromide perovskite monocrystal of a predetermined size is taken out of the open container B, washed with chlorobenzene or cyclohexane to remove the surface-attached solution, vacuum dried at room temperature, and stored in the dark.

[0027] Further, the length and width of the rare earth doped phenethylamine lead bromide perovskite monocrystal of a predetermined size are both centimeter level, and the thickness is millimeter level.

[0028] A large-size rare earth doped phenethylamine lead bromide perovskite monocrystal is prepared by the method.

[0029] The rare earth doped phenethylamine lead bromide perovskite monocrystal has a chemical formula of (C8H 12 N)2PbBr4:Re 3+ , wherein Re represents any one of Nd, Ce and Er.

[0030] The present application has the following beneficial effects:

[0031] 1. The method for preparing a large-size rare earth doped phenethylamine lead bromide perovskite monocrystal uses phenethylamine hydrobromide, lead bromide and rare earth metal bromide as raw materials, and the prepared rare earth doped phenethylamine lead bromide perovskite monocrystal has a size of centimeter level, which can meet the needs of most photoelectric detection devices and has an important supporting role in promoting the performance research of rare earth doped two-dimensional perovskite monocrystals.

[0032] 2. The method for preparing a large-size rare earth doped phenethylamine lead bromide perovskite monocrystal dissolves the raw materials (i.e. phenethylamine hydrobromide, lead bromide and rare earth metal bromide) by heating to obtain a supersaturated precursor solution, and nucleation is achieved by solvent evaporation, which solves the nucleation difficulty caused by heterovalent rare earth ions and shortens the nucleation time.

[0033] 3. The method for preparing a large-size rare earth doped phenethylamine lead bromide perovskite monocrystal seals the open container B after introducing a seed crystal, and the supersaturation of the solution makes the seed crystal grow into a large-size rare earth doped phenethylamine lead bromide perovskite monocrystal, which avoids the problem of water absorption and metamorphism during the growth of the rare earth doped phenethylamine lead bromide perovskite monocrystal. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a flow chart of embodiment 1 of the method for preparing a large-size rare earth doped phenethylamine lead bromide perovskite monocrystal.

[0035] Figure 2(a) is a schematic diagram of the morphology and size of the rare earth doped phenethylamine lead bromide perovskite single crystal prepared by the large-size rare earth doped phenethylamine lead bromide perovskite single crystal preparation method embodiment 1 of the present application;

[0036] Figure 2(b) is a schematic diagram of the morphology and size of the rare earth doped phenethylamine lead bromide perovskite single crystal prepared by the large-size rare earth doped phenethylamine lead bromide perovskite single crystal preparation method embodiment 2 of the present application;

[0037] Figure 2(c) is a schematic diagram of the morphology and size of the single crystal obtained without adding rare earth metal bromide by the large-size rare earth doped phenethylamine lead bromide perovskite single crystal preparation method comparative example;

[0038] Figure 3 is the crystal absorption spectrum (dotted line) and emission spectrum (solid line) of the crystal prepared by the large-size rare earth doped phenethylamine lead bromide perovskite single crystal preparation method embodiment 1 (blue), 2 (red) and comparative example (black) of the present application;

[0039] Figure 4 is the X-ray photoelectron spectrogram of the crystal prepared by the large-size rare earth doped phenethylamine lead bromide perovskite single crystal preparation method embodiment 2 and comparative example of the present application. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0041] Embodiment 1

[0042] A large-size rare earth doped phenethylamine lead bromide perovskite single crystal preparation method, as shown in Figure 1 room temperature 10℃, 20mmol phenethylamine hydrobromide (C8H 12NBr), 10 mmol of lead bromide (PbBr2) and 0.5 mmol of neodymium bromide (NdBr3) in a clean glass bottle; 7.695 mL of N,N-dimethylformamide (DMF) was added to the glass bottle, heated to 30°C using a heating table and stirred until completely dissolved to prepare a precursor solution with a concentration of 1.3 mol / L (expressed in terms of the concentration of lead); the precursor solution was filtered while hot using a polytetrafluoroethylene filter head with a pore size of 0.45 microns, then placed in a clean 100 mL glass beaker and sealed with tin paper, a small hole (1 mm in diameter) was punched in the tin paper using a 10 mL syringe needle, and the beaker was placed in a dry environment for volatilization; within 1 week, crystals with a size of more than a millimeter were precipitated. The solution was filtered into another clean 100 mL beaker, and a piece of crystal that grew independently was selected as a seed crystal and added to the bottom center of the beaker; a heating table was used to place the beaker at 60°C, and after 1 minute, the seed crystal was observed to dissolve significantly; heating was stopped and the beaker was slowly cooled to room temperature (10°C); after 10 days of growth in a quiet place, a centimeter-level two-dimensional lead bromide perovskite single crystal (i.e., a rare earth-doped phenethylamine lead bromide perovskite single crystal) was obtained, as shown in FIG. 2(a); as can be seen from FIG. 2(a), the crystal is hexagonal, with a size of centimeter level and high transparency. The large-size two-dimensional lead bromide perovskite single crystal was taken out using tweezers, the surface solution was absorbed using filter paper, and then the crystal was quickly rinsed with chlorobenzene; after vacuum drying of the room-temperature crystal, the crystal was stored in the dark.

[0043] Example 2

[0044] At room temperature 15℃, 20 mmol of phenethylamine hydrobromide (PEABr), 10 mmol of lead bromide (PbBr2) and 2 mmol of neodymium bromide (NdBr3) were weighed into a clean glass bottle; 7.4 mL of N,N-dimethylformamide (DMF) was added to the glass bottle, heated to 40℃ with a magnetic stirrer and stirred until completely dissolved to prepare a precursor solution with a concentration of 1.35 mol / L (expressed in terms of the concentration of lead); the precursor solution was filtered with a polytetrafluoroethylene filter head with a pore size of 0.22 microns while hot, then placed in a clean 100 mL glass beaker and the beaker was sealed with tin paper, a 10 mL syringe needle was used to punch a small hole in the tin paper, and the solution was evaporated in a dry environment. Within 1 week, crystals with a size of more than a millimeter were precipitated. The solution was filtered into another clean 100 mL beaker, and a piece of transparent and independently grown crystal was taken as a seed crystal and added to it. The beaker was sealed with tin paper, and the tin paper was bound to the outside of the beaker with adhesive tape. The whole was placed on a 60℃ heating platform. After 3 minutes, it was observed that the seed crystal was significantly dissolved. The heating was stopped and the temperature was slowly cooled to room temperature 15℃. After 10 days of growth in a quiet place, a centimeter-level two-dimensional lead bromide perovskite single crystal was obtained, as shown in FIG. 2(b). As can be seen from FIG. 2(b), the original crystal is hexagonal, and is broken from the middle of the crystal when taken out, but still has a centimeter-level size. The large-size two-dimensional lead bromide perovskite single crystal was taken out with tweezers, the surface solution was absorbed with filter paper, and then quickly washed with cyclohexane. After the crystal was dried in a vacuum at room temperature, it was stored in the dark.

[0045] Comparative Example

[0046] At room temperature 20℃, 3.2340g of phenethylamine hydrobromide (PEABr) and 2.9360g of lead bromide (PbBr2) were weighed into a glass reagent bottle, 5.335 mL of N,N-dimethylformamide (DMF) was added (the number of moles of rare earth metal bromide (ReBr3) n3 = 0), heated and stirred to completely dissolve to prepare a 1.5 mol / L solution. The solution was filtered and transferred to a 100ml glass beaker, wrapped with plastic wrap and a 10mL syringe needle was used to punch a small hole in the tin paper. The solution was evaporated in a dry environment. Within 1 week, crystals were precipitated. The solution was filtered into a new clean 100mL beaker, and a piece of independently grown crystal was selected as a seed crystal and added to it. The beaker was sealed with tin paper, and the tin paper was bound to the outside of the beaker with adhesive tape. The whole was placed on a 70℃ heating platform. After 5 minutes, it was observed that the crystal was significantly dissolved. The beaker was transferred to a quiet place for growth. Within 10 days, the size of the crystal reached centimeter level, as shown in FIG. 2(c). The crystal was taken out with tweezers and the surface solution was absorbed with filter paper. It was stored in the dark.

[0047] As Figure 3As shown, the absorption spectrum (dashed line) and emission spectrum (solid line) of the crystal obtained using the method of the present invention according to Examples 1, 2 and the comparative example are shown. The horizontal axis represents the absorption wavelength or emission wavelength, and the vertical axis represents the normalized value of the absorption intensity or emission intensity at that wavelength. The excitation light source used for the emission spectrum is an Xe lamp. The blue line represents the absorption spectrum (dashed line) and emission spectrum (solid line) of the crystal obtained in Example 1, with a wavelength of 350 nm after passing through the grating. The red line represents the absorption spectrum (dashed line) and emission spectrum (solid line) of the crystal obtained in Example 2, with a wavelength of 350 nm after passing through the grating. The black line represents the absorption spectrum (dashed line) and emission spectrum (solid line) of the crystal obtained in the comparative example, with a wavelength of 350 nm after passing through the grating.

[0048] like Figure 4 As shown, the X-ray photoelectron spectra of the crystals prepared according to Example 2 and the comparative example using the method of the present invention are presented. The horizontal axis represents the binding energy, and the vertical axis represents the signal intensity. Figure 4 As can be seen from the crystals prepared according to Example 2 and the comparative example by the method of the present invention, the characteristic peaks of the corresponding orbitals of elements C, Pb and Br can be seen. When the binding energy is between 980 eV and 1020 eV, the characteristic peak of the 3d orbital of the doped Nd element can be seen.

[0049] Example 3

[0050] At room temperature (25°C), weigh 20 mmol of phenylethylamine hydrobromide (PEABr), 10 mmol of lead bromide (PbBr2), and 5 mmol of neodymium bromide (NdBr3) and place them in a clean glass bottle. Add 7.15 mL of N,N-dimethylformamide (DMF) to the glass bottle, heat to 85°C using a magnetic stirrer, and stir until completely dissolved to prepare a precursor solution with a concentration of 1.4 mol / L. Filter the precursor solution through a polytetrafluoroethylene filter with a 0.22-micron pore size, place it in a clean 100 mL glass beaker, seal the beaker with aluminum foil, poke a small hole in the aluminum foil with a 10 mL syringe needle, and place it in a dry environment to evaporate. Within one week, crystals larger than millimeters will precipitate. The solution was filtered into another clean 100mL beaker. A separately grown crystal was added as a seed crystal. The beaker was sealed with aluminum foil and secured to the outside with tape. The entire beaker was placed on a 60℃ heating stage and heated. After 5 minutes, significant dissolution of the seed crystal was observed. Heating was stopped, and the beaker was slowly cooled to room temperature (25℃). The beaker was then transferred to a quiet place and allowed to grow for 15 days, resulting in centimeter-sized two-dimensional lead bromide perovskite single crystals. The large-sized two-dimensional lead bromide perovskite single crystal was removed with tweezers, and the surface solution was absorbed with filter paper. It was then quickly rinsed with chlorobenzene, vacuum dried at room temperature, and stored away from light.

[0051] Example 4

[0052] Room temperature 20℃, take 10mmol phenethylamine hydrobromide (PEABr), 5mmol lead bromide (PbBr2) and 1mmol erbium bromide (ErBr3), placed in a clean glass bottle; then add 3.85mL of N, N-dimethylformamide (DMF) to the glass bottle, heated to 50℃ with a magnetic stirrer and stirred until completely dissolved, made into a precursor solution with a concentration of 1.5mol / L (expressed in terms of lead concentration); the precursor solution is filtered with a 0.22 micron pore size polytetrafluoroethylene filter head while hot, then placed in a clean 50mL glass beaker, and the beaker is sealed with tin paper, a 10mL syringe needle is used to pierce a small hole in the tin paper, and it is placed in a dry environment to evaporate. Within 1 week, crystals with a size of more than millimeter will precipitate. Filter the solution into another clean 50mL beaker, and take a piece of transparent, independently grown crystal as a seed crystal and add it to the beaker. Seal the beaker with tin paper and bind the tin paper to the outside of the beaker with adhesive tape. Place the whole on a 60℃ heating platform. After 4 minutes, observe that the seed crystal is significantly dissolved. Stop heating and slowly cool to room temperature 20℃. After 10 days of growth in a quiet place, centimeter-level two-dimensional lead bromide perovskite single crystals are obtained. Use tweezers to remove the large-size two-dimensional lead bromide perovskite single crystals, use filter paper to absorb the surface solution, then quickly use cyclohexane to rinse, vacuum dry the crystals, and store them in the dark.

[0053] Example 5

[0054] Room temperature 25℃, take 16mmol phenethylamine hydrobromide (PEABr), 8mmol lead bromide (PbBr2) and 2mmol cerium bromide (CeBr3), placed in a clean glass bottle; then add 5.335mL of N, N-dimethylformamide (DMF) to the glass bottle, heated to 60℃ with a magnetic stirrer and stirred until completely dissolved, made into a precursor solution with a concentration of 1.5mol / L (expressed in terms of lead concentration); the precursor solution is filtered with a 0.45 micron pore size polytetrafluoroethylene filter head while hot, then placed in a clean 100mL glass beaker, and the beaker is sealed with tin paper, a 10mL syringe needle is used to pierce a small hole in the tin paper, and it is placed in a dry environment to evaporate. Within 1 week, crystals with a size of more than millimeter will precipitate. Filter the solution into another clean 100mL beaker, and take a piece of transparent, independently grown crystal as a seed crystal and add it to the beaker. Seal the beaker with tin paper and bind the tin paper to the outside of the beaker with adhesive tape. Place the whole on a 70℃ heating platform. After 3 minutes, observe that the seed crystal is significantly dissolved. Stop heating and slowly cool to room temperature 25℃. After 15 days of growth in a quiet place, centimeter-level two-dimensional lead bromide perovskite single crystals are obtained. Use tweezers to remove the large-size two-dimensional lead bromide perovskite single crystals, use filter paper to absorb the surface solution, then quickly use cyclohexane to rinse, vacuum dry the crystals, and store them in the dark.

[0055] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any change or replacement within the technical scope disclosed by the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystals, characterized in that, Includes the following steps: 1) Weighing; Phenethylamine hydrobromide, lead bromide, and rare earth metal bromide are weighed and placed in a glass bottle; the rare earth metal bromide is either NdBr3 or CeBr3. 2) Obtain the precursor solution; Add N,N-dimethylformamide to a glass bottle, heat and stir until completely dissolved to obtain a precursor solution; 3) Obtain millimeter-sized crystals; After filtering the precursor solution, it is placed in an open container A. The open container A is then sealed and connected to the outside through a small hole. It is then placed in a preset temperature and low humidity environment to volatilize until multiple crystals larger than millimeters precipitate. The low humidity environment refers to a relative humidity of less than 40%. 4) Screening seed crystals; Filter the solution in open container A again and put it into open container B; take one crystal from the multiple independently grown crystals of millimeter size and above as a seed crystal and place it in open container B; seal open container B and heat until the seed crystal partially dissolves, stop heating and slowly cool to the preset temperature. 5) Seed crystal growth; The open container B is left to stand at a preset temperature until the seed crystal continues to grow into a rare earth-doped phenylethylamine lead bromide perovskite single crystal of a predetermined size.

2. The method for preparing large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystals according to claim 1, characterized in that: In step 1), the molar numbers of phenylethylamine hydrobromide, lead bromide and rare earth metal bromide are n1, n2 and n3, respectively, and n1:n2:n3 = 2:1:x, x = 0.05~0.

5.

3. The method for preparing large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystals according to claim 2, characterized in that, Step 2) specifically involves: After adding N,N-dimethylformamide to a glass bottle, heat it to 30℃~85℃ using a heating table or magnetic stirrer and stir until completely dissolved to obtain a precursor solution with a lead concentration of 1.3mol / L~1.5mol / L.

4. The method for preparing large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystals according to claim 3, characterized in that: The preset temperature is room temperature, which is 10℃~25℃.

5. The method for preparing large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystals according to claim 4, characterized in that, Step 3) specifically refers to: The precursor solution was filtered using a polytetrafluoroethylene filter with a pore size of 0.45 micrometers or 0.22 micrometers. The filtered solution was placed in an open container A, which was then sealed and a small hole with a diameter of 0.5-1 mm was punched in it. The container was then placed in a room temperature and low humidity environment to evaporate until multiple crystals larger than millimeters precipitated.

6. The method for preparing large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystals according to claim 5, characterized in that: In step 3), "millimeters or above" means greater than or equal to 2 millimeters.

7. The method for preparing large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystals according to claim 6, characterized in that, It also includes step 6): The rare earth-doped phenylethylamine lead bromide perovskite single crystal of predetermined size was taken out from the open container B, cleaned with chlorobenzene or cyclohexane to remove the surface solution, dried under vacuum at room temperature and stored away from light.

8. The method for preparing large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystals according to claim 7, characterized in that: The predetermined rare-earth-doped phenylethylamine lead bromide perovskite single crystal has a length and width in the centimeter range and a thickness in the millimeter range.

9. A large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystal, characterized in that: It was prepared using the method for preparing large-size rare-earth-doped phenylethylamine lead bromide perovskite single crystals as described in any one of claims 1-8; The rare earth-doped phenethylamine lead bromide perovskite single crystal has the chemical formula (C8H). 12 N)2PbBr4:Re 3+ , where Re represents either Nd or Ce.

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