Low-dimensional co-occupying perovskite single crystal and preparation method thereof

Abstract

The invention discloses a low-dimensional co-occupying perovskite single crystal and a preparation method thereof, belongs to the field of photoelectrons, and is a novel photoelectric material in which bismuth and antimony trivalent ions jointly occupy the position of a central cation of a perovskite octahedron. The chemical formula of the novel single crystal is (4AP) SbmBi1-mI5. Wherein A is 4-formamidinopyridine, B is SbmBi (1-m), and X is I; 4-formamidinopyridine has richer hydrogen bond donors than amino groups and has lower acidity and polarity than amino cations of the same type, and meanwhile, due to a special bimetal co-occupation structure, the crystal has more comprehensive performance than a single metal-based perovskite single crystal. Therefore, when the perovskite material is formed, compared with other metal halide perovskite materials with a single metal base or amido and the like, the single crystal prepared in the invention shows a lower ion migration phenomenon and more excellent photoelectric properties.

Description

Technical Field

[0001] The invention belongs to the field of optoelectronic technology, and in particular relates to a low-dimensional co-occupied perovskite single crystal and a preparation method thereof. Background Art

[0002] Perovskite single crystal refers to a crystalline material composed of perovskite structural units. The perovskite structure is a cubic crystal structure, and its basic unit is ABX3, where A and B represent cations, such as iron, aluminum, magnesium, and manganese, and X represents anions, such as oxygen and chlorine. The perovskite structural unit has the characteristics of good symmetry, strong crystal stability, and excellent electrical and optical properties. Due to its excellent optoelectronic and electrical properties, perovskite single crystals have been widely used in optoelectronic devices, batteries and other fields. For example, perovskite single crystals can be used in the field of solar cells to prepare solar cells with high efficiency and good stability; they can also be used in the field of photodetectors to prepare detectors with high sensitivity and high response speed.

[0003] Metal halide perovskite single crystals have become one of the most promising candidate materials for the next generation of photovoltaic devices due to their excellent optoelectronic properties, including high absorption coefficient, excellent bipolar charge mobility, long carrier diffusion length, small exciton binding energy and ideal band gap. However, while considering high performance, it is also necessary to consider the practical application of perovskite single crystals. In current technology, the B-site metal ions in the metal halide perovskites that have been studied more are mostly lead, bismuth, cesium, antimony, etc. Due to the serious problems of these metal halide perovskites such as toxicity, easy decomposition, environmental instability, and ion migration, they are not conducive to the application stability of the perovskite single crystal device structure, which in turn limits its further application. Although many bulk doping and interface modification methods have suppressed its ion migration and degradation during operation to a certain extent, they have not solved the stability problem from the fundamental properties of the perovskite structure. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to propose a low-dimensional co-occupied perovskite single crystal and a preparation method thereof, so as to solve the problems in the prior art such as poor stability of amino perovskite and shortcomings in device performance caused by the single B-site metal element.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing a low-dimensional co-occupied perovskite single crystal comprises the following steps:

[0007] Step 1, mixing 4-carbamimidoylpyridine hydrochloride, a mixture of bismuth oxide and antimony oxide, and hydroiodic acid, wherein the hydroiodic acid is used as a solvent, stirring at 120-180° C. to obtain a clear solution, and keeping the clear solution at 120-180° C. to obtain a saturated solution of a low-dimensional co-occupied perovskite single crystal, which is a low-dimensional co-occupied perovskite single crystal precursor solution;

[0008] Step 2, reducing the temperature of the low-dimensional co-occupied perovskite single crystal precursor solution at a rate of 0.2 to 2°C / h, and after reducing it to room temperature, obtaining a low-dimensional co-occupied perovskite single crystal ABX5, wherein A is a large-sized organic 4-carboxamidinium pyridinium cation, and B is Sb m Bi 1-m , X is I, 0<m<1.

[0009] A further improvement of the present invention is:

[0010] Preferably, in step 1, the mixing molar ratio of 4-carbamimidoylpyridine hydrochloride to bismuth oxide and antimony oxide is 1:1.

[0011] Preferably, in step 1, the process of mixing 4-carbamimidinopyridine hydrochloride, a mixture of bismuth oxide and antimony oxide, and hydroiodic acid is: adding the mixture of 4-carbamimidinopyridine hydrochloride, bismuth oxide and antimony oxide to a container, adding hydroiodic acid, dissolving the mixture of amidino hydrochloride, bismuth oxide and antimony oxide, stirring at 120-180° C. to obtain a clear solution, and keeping it still at 120-180° C. to obtain a saturated solution of a low-dimensional co-occupied perovskite single crystal.

[0012] Preferably, in step 1, bismuth oxide and antimony oxide are dissolved in hydroiodic acid, stirred at 120-180° C. to obtain a clear solution, 4-carbamimidoylpyridine hydrochloride is added to the clear solution, and stirring is continued at 120-180° C. to obtain a clear solution, and after keeping still at 120-180° C., a saturated solution of a low-dimensional co-occupied perovskite single crystal is obtained.

[0013] Preferably, in step 1, the mass fraction of the hydrofluoric acid aqueous solution is 55%-57%.

[0014] Preferably, in step 1, hypophosphorous acid in an amount of 10-30% by volume of the aqueous hydroiodic acid solution is added to the aqueous hydroiodic acid solution.

[0015] Preferably, in step 2, the room temperature is 25-30°C.

[0016] Preferably, after step 2, the low-dimensional co-occupied perovskite single crystal ABX5 is immersed in an anti-solvent, and after the anti-solvent soaked with the low-dimensional co-occupied perovskite single crystal is filtered out, the surface of the single crystal is polished with sandpaper, and after polishing, it is polished with sandpaper, and the polished single crystal is dried and further polished to obtain the final low-dimensional co-occupied perovskite single crystal ABX5 thin sheet.

[0017] A low-dimensional co-occupied perovskite single crystal prepared by any one of the above preparation methods, wherein the structural formula of the low-dimensional co-occupied perovskite single crystal is ABX5, wherein A is a large-sized organic 4-formamidinium pyridinium cation, B is Sb m Bi 1-m , X is I, 0<m<1.

[0018] 10. The low-dimensional co-occupied perovskite single crystal according to claim 9, characterized in that the ABX5 is (4AP)Sb 0.75 Bi 0.25 I5、(4AP)Sb 0.55 Bi 0.45 I5 or (4AP)Sb 0.34 Bi 0.66 I5.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention discloses a method for preparing a low-dimensional co-occupied perovskite single crystal, which is ... 3+ and Bi 3+ A new type of perovskite photoelectric material with cations occupying the B position together. The chemical formula of the single crystal is ABX5, where A is a large-sized organic molecule 4-methylguanidine pyridine and B is Sb m Bi 1-m , X is I; 4-carbamimidinopyridine has a richer hydrogen bond donor than amine groups, and has lower acidity and polarity than the same type of amine cations. The preparation method uses a single crystal growth method, which is a slow solution cooling method. It is easy to operate and is not limited by equipment. The method is simple and cost-effective. The growth cycle is relatively short, and it is easy to cultivate single crystals with a size greater than 3×3×1mm. 3 Low-dimensional co-occupied perovskite single crystals.

[0021] Furthermore, the large-sized low-dimensional co-occupied perovskite single crystal prepared by the method is wiped, surface cleaned and double-sided polished, and then sealed and stored in a drying cabinet for subsequent use.

[0022] The present invention discloses a low-dimensional co-occupied perovskite single crystal, which improves the environmental stability of the perovskite material compared with low-dimensional amine-based perovskites; compared with other perovskite single crystals of the same type, the bimetallic co-occupied perovskite single crystal has a lower octahedral torsion factor and a shorter bond length, further improving the carrier transmission efficiency and slowing down the ion migration phenomenon inside the device. In addition, the bimetallic co-occupancy enables the perovskite single crystal to have the excellent properties of both bismuth-based and antimony-based halide perovskites, and abandons the problem of single performance of single metal perovskite single crystals. At the same time, the bimetallic co-occupancy further improves the photoelectric performance of a single metal halide perovskite, and has a lower ion migration phenomenon. The single crystal material opens up a new path for the application of perovskite photoelectric materials. The new perovskite single crystal of the present invention promotes the application research in aspects such as the stability of perovskites, the development of new materials, and the application of new perovskite photoelectric materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is (4AP)Sb in Example 2 of the present invention 0.75 Bi 0.25 Schematic diagram of the growth process of I5 single crystal.

[0024] Figure 2 is (4AP)Sb in Example 2 of the present invention 0.75 Bi 0.25 Physical picture of I5 single crystal.

[0025] Figure 3 The single crystal (4AP)Sb in Example 2 of the present invention 0.75 Bi 0.25 Crystal structure of I5.

[0026] Figure 4 The single crystal (4AP)Sb in Example 2 of the present invention 0.75 Bi 0.25 X-ray diffraction pattern of the top surface of I5.

[0027] Figure 5 The crystal (4AP)Sb in Example 2 of the present invention 0.75 Bi 0.25 X-ray diffraction pattern of I5 powder after being stored in a relative humidity of 40% for 60 days.

[0028] Figure 6 The single crystal (4AP)Sb described in Example 2 0.75 Bi 0.25 UV absorption spectrum of I5 and calculated diagram of its indirect band gap. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0030] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0031] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0032] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0033] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0034] The first aspect of the present invention discloses a method for preparing a low-dimensional co-occupied perovskite single crystal, which adopts a solution method to cultivate a single crystal with a size of not less than 3×3×1 mm. 3 The structure of the low-dimensional co-occupied perovskite single crystal is ABX5, where A is a large-sized organic 4-carboxamidinopyridinium cation and B is Sb m Bi 1-m , X is I; the structural formula of the amidinopyridinium cation is:

[0035]

[0036] Specifically, the method for culturing low-dimensional co-occupied perovskite single crystals by solution method is to mix and dissolve amidine hydrochloride, bismuth oxide, antimony oxide and hydroiodic acid in different proportions, then gradually cool down and finally cultivate and grow to obtain low-dimensional co-occupied perovskite single crystals. For detailed preparation methods, see Figure 1 , including the following steps:

[0037] Step 1, preparing a low-dimensional co-occupied perovskite single crystal;

[0038] Step 1.1, preparation of low-dimensional co-occupied perovskite single crystal precursor solution. There are two methods to prepare the precursor solution:

[0039] Method 1: Add amidine hydrochloride and bismuth oxide / antimony oxide in a molar ratio of 1:1 into a beaker, and add excess hydroiodic acid dropwise. The bismuth antimony metal content in the final bismuth-antimony co-occupied perovskite single crystal product is determined by the different ratios of bismuth oxide and antimony oxide; continuously stir or oscillate or ultrasonically stir evenly at 120-180°C to react until a clear solution is obtained; after obtaining a clear solution, keep it warm at the corresponding stirring temperature for two hours to obtain a saturated solution of a low-dimensional co-occupied perovskite single crystal, which is a low-dimensional co-occupied perovskite single crystal precursor solution.

[0040] Method 2: Dissolve bismuth oxide and antimony oxide in appropriate amount of hydroiodic acid in different proportions and place on a hot plate. Stir continuously at a temperature of 120-180°C until a clear solution is obtained. Specifically, the solution in which the oxides are dissolved has the same color as hydroiodic acid, that is, it is reddish brown.

[0041] As a preferred solution, the concentration of the hydroiodic acid aqueous solution is 55%-57%.

[0042] Add 4-carbamimidoylpyridine hydrochloride in an equal molar amount to bismuth oxide and antimony oxide to the above clear solution, continue stirring at a preparation temperature of 120-180°C until a clear solution is obtained, and keep warm at the corresponding stirring temperature for two hours to obtain a saturated solution of a low-dimensional co-occupied perovskite single crystal, which is a low-dimensional co-occupied perovskite single crystal precursor solution. Specifically, when the bismuth oxide content is higher, the solution color is orange-red, and when the antimony oxide content is high, the solution is more inclined to orange-yellow.

[0043] It should be understood that in the above preparation process, the solution is limited to a saturated solution to prevent the final single crystal from having too many undissolved impurities due to the solution not being a saturated solution.

[0044] It should be understood that the dissolution temperature of the present invention is 120-180°C, which is the crystallization temperature of the single crystal of the component. In the process of preparing the perovskite single crystal precursor solution, it can be found that the more antimony oxide content, the more difficult the solution is to dissolve; conversely, when the bismuth oxide content increases, the solubility of the solution increases. Experiments show that when the precursor solution contains only bismuth oxide and no antimony oxide, the solute can be completely dissolved at 120°C; and as the antimony oxide content in the solution continues to increase, the temperature required for the solute to completely dissolve also increases to 180°C.

[0045] It should be noted that since the halogen of the target low-dimensional co-occupied perovskite single crystal is I, when preparing the precursor solution for growing the low-dimensional co-occupied perovskite single crystal, a hypophosphorous acid solution with a volume of 10-30% of hydroiodic acid needs to be added as a stabilizer to achieve I in the solution. - At the same time, the growth solution needs to be placed in a light-proof environment to alleviate the oxidation process of iodine ions.

[0046] It should be understood that during the precursor preparation process, the temperature affects the solubility of the reactants. Here, when hydroiodic acid is used as the solvent, the higher the temperature, the greater the solubility of the corresponding oxide solute. The concentrations of the solutions obtained at different temperatures are different, so the crystal sizes obtained are different.

[0047] Step 1.2, growth of low-dimensional co-occupied perovskite single crystal;

[0048] Starting from the dissolution temperature of the low-dimensional co-occupied perovskite single crystal precursor solution (the dissolution temperature is 120℃-180℃ mentioned above), within 1-30 days, the temperature of the precursor solution is gradually and slowly lowered to 25-30℃, and a single crystal with a size greater than 3×3×1mm can be obtained. 3 Low-dimensional co-occupied perovskite single crystal materials.

[0049] In the experiment, the cooling rate was 0.2 to 2°C / h. Different cooling rates resulted in different crystal sizes. A slow cooling rate was more conducive to the generation of large-size, high-quality perovskite single crystals.

[0050] Specifically, during the slow cooling process, the low-dimensional co-occupied perovskite single crystal should be placed in a quiet environment to prevent vibration.

[0051] In step 1, when the ratio of bismuth oxide and antimony oxide added is different, the molecular formula of the perovskite single crystal from the highest antimony content to the lowest is (4AP)SbI5, (4AP)Sb 0.75 Bi 0.25 I 5， (4AP)Sb 0.55 Bi 0.45 I 5， (4AP)Sb 0.34 Bi 0.66 I5 and (4AP)BiI 5。。

[0052] Step 2: Take out the large-sized low-dimensional co-occupied perovskite single crystal obtained from the solution with tweezers, wipe off the residual solvent on the surface with dust-free paper or filter paper, and then perform surface cleaning, filtration and polishing. The specific steps are as follows:

[0053] Step 2.1, take out the low-dimensional co-occupied perovskite single crystal from the growth solution with tweezers, and carefully wipe the solution on the surface of the single crystal with dust-free paper or filter paper;

[0054] Step 2.2, soaking the surface of the low-dimensional co-occupied perovskite single crystal with an anti-solvent such as anhydrous ether, dichloromethane, acetone or toluene, filtering the anti-solvent mixed solution soaked with the low-dimensional co-occupied perovskite single crystal with a sand core funnel, polishing the surface of the single crystal with sandpaper, and after polishing, using the anti-solvent again to clean the residue left on the surface when the sandpaper is polished;

[0055] Step 2.3, placing the low-dimensional co-occupied perovskite single crystal in an oven for drying to remove the anti-solvent remaining on the surface of the single crystal; the drying temperature is 60°C, and the drying time is 24 hours; after drying, the surface of the dried single crystal is polished and grinded using 2000, 5000, and 7000 mesh sandpapers.

[0056] One of the embodiments of the present invention discloses a low-dimensional co-occupied perovskite single crystal prepared by the above method, wherein the size of the low-dimensional co-occupied perovskite single crystal is slightly larger than 3×3×1 mm 3 .

[0057] The second aspect of the present invention discloses a low-dimensional co-occupied perovskite single crystal prepared by the above-mentioned preparation method. The prepared low-dimensional co-occupied perovskite single crystal has a chemical formula of (4AP)Sb m Bi 1-m I5, where 0<m<1, their structure contains inorganic octahedron (specifically [Sb m Bi 1-m I5] 2- ) are connected in a corner-sharing manner to form a one-dimensional perovskite structure, and the size of the low-dimensional co-occupied perovskite single crystal is smaller than that of the lead-based halide perovskite single crystal.

[0058] When the ratio of bismuth oxide and antimony oxide added is different, the molecular formula of the perovskite single crystal from the highest antimony content to the lowest is (4AP)Sb 0.75 Bi 0.25 I5, (4AP)Sb 0.55 Bi 0.45 I5 and (4AP)Sb 0.34 Bi 0.66 I5.

[0059] The following is further described in conjunction with specific embodiments:

[0060] Example 1

[0061] 1. First, weigh 0.292g (1mmol) of antimony oxide and place it in a beaker, add a stirring magnet, add 40mL of 55%-57% hydroiodic acid aqueous solution, heat it on a hot plate at 120℃, and stir vigorously until a clear brown solution is obtained. Add 0.158g of 4-carboxamidinopyridine hydrochloride (1mmol) to the above solution, continue to stir on a hot plate at 120℃, and continue to add 4mL of 50% hypophosphorous acid solution until the solute is completely dissolved. Then place the mixed solution on a hot plate at 120℃ and stir for 24 hours to obtain a clear and transparent orange-yellow perovskite single crystal solution.

[0062] 2. Start from the preparation temperature of 120℃ and gradually and slowly cool down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is about 15-30 days. At this time, the size can be slightly larger than 3×3×1mm 3 of single crystal.

[0063] 3. Use tweezers to take out the obtained (4AP)SbI5 single crystal from the solution, and use dust-free paper or filter paper to absorb the excess liquid on the surface of the single crystal. Then use the anti-solvent anhydrous ether to wash the crystal and filter it. Place the washed single crystal in a vacuum oven at 60°C and dry it for one day.

[0064] 4. The upper and lower surfaces of the dried low-dimensional antimony-based perovskite single crystal (4AP) SbI5 were polished using 2000, 5000, and 7000 grit sandpapers, respectively.

[0065] 5. Encapsulate the processed low-dimensional perovskite single crystal and place it in a drying cabinet for later use.

[0066] Example 2

[0067] 1. First, weigh 0.1752g (0.6mmol) of antimony oxide and 0.1864g (0.4mmol) of bismuth oxide into a beaker, add a stirring magnet, add 30mL of 55%-57% hydroiodic acid aqueous solution, heat it on a hot plate at 120℃, and stir vigorously until a clear brown solution is obtained. Add 0.158g (1mmol) of 4-carboxamidinopyridine hydrochloride to the above solution, continue stirring on a hot plate at 120℃, and continue to add 3mL of 50% hypophosphorous acid solution until the solute is completely dissolved. Then place the mixed solution on a hot plate at 120℃ and stir for 24 hours to obtain a clear and transparent orange-red perovskite single crystal solution.

[0068] 2. Start from the preparation temperature of 120℃ and gradually and slowly cool down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is 15-30 days, at which time the size of the single crystal solution larger than 3×3×1mm can be obtained.3 of single crystal.

[0069] 3. Use tweezers to remove the obtained (4AP)Sb 0.75 Bi 0.25 The I5 single crystal was taken out from the solution, and the excess liquid on the surface of the single crystal was first absorbed using dust-free paper or filter paper. The crystal was then washed with an anti-solvent anhydrous ether and filtered. The washed single crystal was placed in a vacuum oven at 60°C and dried for one day.

[0070] 4. The dried low-dimensional bismuth-antimony co-occupied perovskite single crystal (4AP)Sb 0.75 Bi 0.25 The upper and lower surfaces of I5 were polished using 2000, 5000, and 7000 grit sandpaper.

[0071] 5. Encapsulate the processed low-dimensional co-occupied perovskite single crystal and place it in a drying cabinet for later use.

[0072] The low-dimensional bismuth-antimony co-occupied perovskite single crystal obtained by gradual and slow cooling has a simple preparation process and low preparation cost. The size of the obtained single crystal can reach 10.1×8.3×2.3mm 3 . The actual photo of the single crystal is as follows Figure 2 shown.

[0073] Figure 3 The crystal structure diagram of a single crystal. It can be seen from the figure that iodine atoms occupy the six vertices of the perovskite octahedron, Sb m Bi 1-m Located at the center of the octahedron, countless octahedra are connected to each other in a common point manner to form several long chains, which shows a typical one-dimensional perovskite single crystal structure. Among them, the organic molecule 4-carboxamidinylpyridinium cation is distributed between the octahedral chains through hydrogen bonds and other bonding interactions.

[0074] Figure 4 This is the crystal plane XRD of a single crystal. From the figure, we can see that the XRD diffraction peaks of the single crystal are separated by the same interlayer spacing, grow along the (002) crystal plane, and the crystal structure is neatly arranged.

[0075] Figure 5 The PXRD test results of the crystal placed at a relative humidity of 40% and a temperature of 25°C for 60 days are shown in the figure. As can be seen from the figure, after the crystal has been placed for 60 days, it still maintains the same diffraction peaks as fresh crystals, proving that the crystal has excellent moisture stability and environmental stability in the air.

[0076] Figure 6 The ultraviolet absorption spectrum of the single crystal and its indirect band gap diagram. It can be seen from the figure that the absorption edge of the perovskite single crystal is about 660nm, and its indirect band gap can be calculated to be 1.76eV.

[0077] The perovskite single crystal in Example 2 of the present invention has excellent wet-heat stability and excellent detection sensitivity compared to the amine-based perovskite single crystal radiation detector. Therefore, the present invention helps to improve the stability of perovskite materials and provides a new direction for the construction of new perovskite single crystal materials and their applications in the field of radiation detection.

[0078] Example 3

[0079] 1. First, weigh 0.0876g of antimony oxide and 0.3262g of bismuth oxide and place them in a beaker, add a stirring magnet, add 25mL of 55%-57% hydroiodic acid aqueous solution, heat it on a hot plate at 120℃, and stir vigorously until a clear brown solution is obtained. Add 0.158g of 4-methylguanidine pyridine hydrochloride to the above solution, continue stirring on a hot plate at 120℃, and continue to add 2.5mL of 50% hypophosphorous acid solution until the solute is completely dissolved. Then place the mixed solution on a hot plate at 120℃ and stir for 24 hours to obtain a clear and transparent orange-red perovskite single crystal solution.

[0080] 2. Start from the preparation temperature of 120℃ and gradually and slowly cool down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is 15-30 days, at which time the size of the single crystal solution larger than 3×3×1mm can be obtained. 3 of single crystal.

[0081] 3. Use tweezers to remove the obtained (4AP)Sb 0.55 Bi 0.45 The I5 single crystal was taken out from the solution, and the excess liquid on the surface of the single crystal was first absorbed using dust-free paper or filter paper. The crystal was then washed with an anti-solvent anhydrous ether and filtered. The washed single crystal was placed in a vacuum drying oven at 60°C and dried for one day.

[0082] 4. The dried low-dimensional bismuth-antimony co-occupied perovskite single crystal (4AP)Sb 0.55 Bi 0.45 One side of I5 was polished with 2000, 5000, and 7000 grit sandpaper respectively.

[0083] 5. Encapsulate the processed low-dimensional co-occupied perovskite single crystal and place it in a drying cabinet for later use.

[0084] Example 4

[0085] 1. First, weigh 0.0584g of antimony oxide and 0.3728g of bismuth oxide and place them in a beaker, add a stirring magnet, add 22mL of 55%-57% hydroiodic acid aqueous solution, heat it on a hot plate at 120℃, and stir vigorously until a clear brown solution is obtained. Add 0.158g of 4-methylguanidine pyridine hydrochloride to the above solution, continue to stir on a hot plate at 120℃, and continue to add 2.2mL of 50% hypophosphorous acid aqueous solution until the solute is completely dissolved. Then place the mixed solution on a hot plate at 120℃ and stir for 24 hours to obtain a clear and transparent orange-red perovskite single crystal solution.

[0086] 2. Start from the preparation temperature of 120℃ and gradually and slowly cool down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is 15-30 days, at which time the size of the single crystal solution larger than 3×3×1mm can be obtained. 3 of single crystal.

[0087] 3. Use tweezers to remove the obtained (4AP)Sb 0.34 Bi 0.66 The I5 single crystal was taken out from the solution, and the excess liquid on the surface of the single crystal was first absorbed using dust-free paper or filter paper. The crystal was then washed with an anti-solvent anhydrous ether and filtered. The washed single crystal was placed in a vacuum drying oven at 60°C and dried for one day.

[0088] 4. The dried low-dimensional bismuth-antimony co-occupied perovskite single crystal (4AP)Sb 0.34 Bi 0.66 The upper and lower surfaces of I5 were polished using 2000, 5000, and 7000 grit sandpapers, respectively.

[0089] 5. Encapsulate the processed low-dimensional co-occupied perovskite single crystal and place it in a drying cabinet for later use.

[0090] Example 5

[0091] 1. First, weigh 0.466g of bismuth oxide and place it in a beaker, add a stirring magnet, add 20mL of 55%-57% hydroiodic acid aqueous solution, heat it on a hot plate at 120℃, and stir vigorously until a clear brown solution is obtained. Add 0.158g of 4-carboxamidinopyridine hydrochloride to the above solution, continue stirring on a hot plate at 120℃, and continue to add 2mL of 50% hypophosphorous acid solution until the solute is completely dissolved. Then place the mixed solution on a hot plate at 120℃ and stir for 24 hours to obtain a clear and transparent orange-red perovskite single crystal solution.

[0092] 2. Start from the preparation temperature of 120℃ and gradually and slowly cool down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is 15-30 days, at which time the size of the single crystal solution larger than 3×3×1mm can be obtained. 3 of single crystal.

[0093] 3. Use tweezers to take out the obtained (4AP)BiI5 single crystal from the solution, and use dust-free paper or filter paper to absorb the excess liquid on the surface of the single crystal. Then use anti-solvent acetone to wash the crystal and filter it. Place the washed single crystal in a vacuum drying oven at 60°C and dry it for one day.

[0094] 4. The upper and lower surfaces of the dried low-dimensional bismuth-based perovskite single crystal (4AP)BiI5 were polished using 2000, 5000, and 7000 grit sandpaper respectively.

[0095] 5. Encapsulate the processed low-dimensional co-occupied perovskite single crystal and place it in a drying cabinet for later use.

[0096] Example 6

[0097] 1. First, weigh 0.1752g of antimony oxide, 0.1864g of bismuth oxide and 0.158g of 4-carbamimidoylpyridine hydrochloride and place them in a beaker, add a stirring magnet, add 30mL of 55%-57% hydroiodic acid aqueous solution and 3mL of 50% hypophosphorous acid solution, heat it on a hot plate at 120℃, and stir vigorously until the solute is completely dissolved. Then place the mixed solution on a hot plate at 120℃ and stir for 24 hours to obtain a clear and transparent orange-red perovskite single crystal solution.

[0098] 2. Start from the preparation temperature of 120℃ and gradually and slowly cool down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is 15-30 days, at which time the size of the single crystal solution larger than 3×3×1mm can be obtained. 3 of single crystal.

[0099] 3. Use tweezers to remove the obtained (4AP)Sb 0.75 Bi 0.25 The I5 single crystal was taken out from the solution, and the excess liquid on the surface of the single crystal was first absorbed using dust-free paper or filter paper. The crystal was then washed with an anti-solvent anhydrous ether and filtered. The washed single crystal was placed in a vacuum drying oven at 60°C and dried for one day.

[0100] 4. The dried low-dimensional bismuth-antimony co-occupied perovskite single crystal (4AP)Sb 0.75 Bi 0.25 The upper and lower surfaces of I5 were polished using 2000, 5000, and 7000 grit sandpapers, respectively.

[0101] 5. Encapsulate the processed low-dimensional co-occupied perovskite single crystal and place it in a drying cabinet for later use.

[0102] Example 7

[0103] 1. First, weigh 0.1752g of antimony oxide and 0.1864g of bismuth oxide and place them in a beaker, add a stirring magnet, add 30mL of 55%-57% hydroiodic acid aqueous solution, heat it on a hot plate at 140℃, and stir vigorously until a clear brown solution is obtained. Add 0.158g of 4-methylguanidine pyridine hydrochloride to the above solution, continue stirring on a hot plate at 140℃, and continue to add 3mL of 50% hypophosphorous acid solution until the solute is completely dissolved. Then place the mixed solution on a hot plate at 140℃ and stir for 24 hours to obtain a clear and transparent orange-red perovskite single crystal solution.

[0104] 2. Start from the preparation temperature of 140℃ and gradually and slowly cool down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is 15-30 days, at which time the size of the single crystal solution larger than 3×3×1mm can be obtained. 3 of single crystal.

[0105] 3. Use tweezers to remove the obtained (4AP)Sb 0.75 Bi 0.25 The I5 single crystal was taken out from the solution, and the excess liquid on the surface of the single crystal was first absorbed using dust-free paper or filter paper. The crystal was then washed with an anti-solvent anhydrous ether and filtered. The washed single crystal was placed in a vacuum drying oven at 60°C and dried for one day.

[0106] 4. The dried low-dimensional bismuth-antimony co-occupied perovskite single crystal (4AP)Sb 0.75 Bi 0.25 The upper and lower surfaces of I5 were polished using 2000, 5000, and 7000 grit sandpapers, respectively.

[0107] 5. Encapsulate the processed low-dimensional co-occupied perovskite single crystal and place it in a drying cabinet for later use.

[0108] Example 8

[0109] 1. First, weigh 0.1752g of antimony oxide, 0.1864g of bismuth oxide and 0.158g of 4-carbamimidoylpyridine hydrochloride and place them in a beaker, add a stirring magnet, add 30mL of 55%-57% hydroiodic acid aqueous solution and 3mL of 50% hypophosphorous acid solution, heat it on a hot plate at 180℃, and stir vigorously until the solute is completely dissolved. Then place the mixed solution on a hot plate at 180℃ and stir for 24 hours to obtain a clear and transparent orange-red perovskite single crystal solution.

[0110] 2. Start from the preparation temperature of 180℃ and gradually and slowly cool it down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is 15-30 days, at which time the size of the single crystal solution larger than 3×3×1mm can be obtained. 3 of single crystal.

[0111] 3. Use tweezers to remove the obtained (4AP)Sb 0.75 Bi 0.25 The I5 single crystal was taken out from the solution, and the excess liquid on the surface of the single crystal was first absorbed using dust-free paper or filter paper. The crystal was then washed with an anti-solvent anhydrous ether and filtered. The washed single crystal was placed in a vacuum drying oven at 60°C and dried for one day.

[0112] 4. The dried low-dimensional bismuth-antimony co-occupied perovskite single crystal (4AP)Sb 0.75 Bi 0.25 The upper and lower surfaces of I5 were polished using 2000, 5000, and 7000 grit sandpapers, respectively.

[0113] 5. Encapsulate the processed low-dimensional co-occupied perovskite single crystal and place it in a drying cabinet for later use.

[0114] Example 9

[0115] 1. First, weigh 0.1752g of antimony oxide, 0.1864g of bismuth oxide and 0.158g of 4-carbamimidoylpyridine hydrochloride into a beaker, add a stirring magnet, add 30mL of 55%-57% hydroiodic acid aqueous solution and 6mL of 50% hypophosphorous acid solution, heat it on a hot plate at 180℃, and stir vigorously until the solute is completely dissolved. Then, place the mixed solution on a hot plate at 180℃ and stir for 24 hours to obtain a clear and transparent orange-red perovskite single crystal solution.

[0116] 2. Start from the preparation temperature of 180℃ and gradually and slowly cool it down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is 15-30 days, at which time the size of the single crystal solution larger than 3×3×1mm can be obtained. 3 of single crystal.

[0117] 3. Use tweezers to remove the obtained (4AP)Sb 0.75 Bi 0.25 The I5 single crystal was taken out from the solution, and the excess liquid on the surface of the single crystal was first absorbed using dust-free paper or filter paper. The crystal was then washed with an anti-solvent anhydrous ether and filtered. The washed single crystal was placed in a vacuum drying oven at 60°C and dried for one day.

[0118] 4. The dried low-dimensional bismuth-antimony co-occupied perovskite single crystal (4AP)Sb 0.75 Bi 0.25The upper and lower surfaces of I5 were polished using 2000, 5000, and 7000 grit sandpapers, respectively.

[0119] 5. Encapsulate the processed low-dimensional co-occupied perovskite single crystal and place it in a drying cabinet for later use.

[0120] Example 10

[0121] 1. First, weigh 0.1752g of antimony oxide, 0.1864g of bismuth oxide and 0.158g of 4-carbamimidoylpyridine hydrochloride and place them in a beaker, add a stirring magnet, add 30mL of 55%-57% hydroiodic acid aqueous solution and 9mL of 50% hypophosphorous acid solution, heat it on a hot plate at 180℃, and stir vigorously until the solute is completely dissolved. Then place the mixed solution on a hot plate at 180℃ and stir for 24 hours to obtain a clear and transparent orange-red perovskite single crystal solution.

[0122] 2. Start from the preparation temperature of 180℃ and gradually and slowly cool it down to 25℃. During the cooling process, keep the environment of the single crystal solution relatively quiet to prevent vibration. The required cooling time is 15-30 days, at which time the size of the single crystal solution larger than 3×3×1mm can be obtained. 3 of single crystal.

[0123] 3. Use tweezers to remove the obtained (4AP)Sb 0.75 Bi 0.25 The I5 single crystal was taken out from the solution, and the excess liquid on the surface of the single crystal was first absorbed using dust-free paper or filter paper. The crystal was then washed with an anti-solvent anhydrous ether and filtered. The washed single crystal was placed in a vacuum drying oven at 60°C and dried for one day.

[0124] 4. The dried low-dimensional bismuth-antimony co-occupied perovskite single crystal (4AP)Sb 0.75 Bi 0.25 The upper and lower surfaces of I5 were polished using 2000, 5000, and 7000 grit sandpapers, respectively.

[0125] 5. Encapsulate the processed low-dimensional co-occupied perovskite single crystal and place it in a drying cabinet for later use.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a low-dimensional co-occupied perovskite single crystal, characterized in that: The following steps are involved: Step 1, mixing 4-carbamimidoylpyridine hydrochloride, a mixture of bismuth oxide and antimony oxide, and hydroiodic acid, wherein the hydroiodic acid is used as a solvent, stirring at 120-180° C. to obtain a clear solution, and keeping the clear solution at 120-180° C. to obtain a saturated solution of a low-dimensional co-occupied perovskite single crystal, which is a low-dimensional co-occupied perovskite single crystal precursor solution; Step 2, reducing the temperature of the low-dimensional co-occupied perovskite single crystal precursor solution at a rate of 0.2 to 2°C / h, and after reducing it to room temperature, obtaining a low-dimensional co-occupied perovskite single crystal ABX5, wherein A is a large-sized organic 4-carboxamidinium pyridinium cation, and B is Sb m Bi 1-m , X is I, 0<m<1.

2. The method for preparing a low-dimensional co-occupied perovskite single crystal according to claim 1, characterized in that: In step 1, the mixing molar ratio of 4-carbamimidyl pyridine hydrochloride to bismuth oxide and antimony oxide is 1:

1.

3. The method for preparing a low-dimensional co-occupied perovskite single crystal according to claim 1, characterized in that: In step 1, the process of mixing 4-carbamimidinopyridine hydrochloride, a mixture of bismuth oxide and antimony oxide, and hydroiodic acid is as follows: adding the mixture of 4-carbamimidinopyridine hydrochloride, bismuth oxide and antimony oxide to a container, adding hydroiodic acid, dissolving the mixture of amidino hydrochloride, bismuth oxide and antimony oxide, stirring at 120-180° C. to obtain a clear solution, and keeping it still at 120-180° C. to obtain a saturated solution of a low-dimensional co-occupied perovskite single crystal.

4. The method for preparing a low-dimensional co-occupied perovskite single crystal according to claim 1, characterized in that: In step 1, bismuth oxide and antimony oxide are dissolved in hydroiodic acid, stirred at 120-180° C. to obtain a clear solution, 4-carbamimidoylpyridine hydrochloride is added to the clear solution, and stirring is continued at 120-180° C. to obtain a clear solution, which is kept warm and allowed to stand at 120-180° C. to obtain a saturated solution of a low-dimensional co-occupied perovskite single crystal.

5. The method for preparing a low-dimensional co-occupied perovskite single crystal according to claim 1, characterized in that: In step 1, the mass fraction of the hydrofluoric acid aqueous solution is 55%-57%.

6. The method for preparing a low-dimensional co-occupied perovskite single crystal according to claim 1, characterized in that: In step 1, hypophosphorous acid in an amount of 10-30% by volume of the aqueous hydroiodic acid solution is added to the aqueous hydroiodic acid solution.

7. The method for preparing a low-dimensional co-occupied perovskite single crystal according to claim 1, characterized in that: In step 2, the room temperature is 25-30°C.

8. The method for preparing a low-dimensional co-occupied perovskite single crystal according to claim 1, characterized in that: After step 2, the low-dimensional co-occupied perovskite single crystal ABX5 is immersed in an anti-solvent, and after the anti-solvent soaked with the low-dimensional co-occupied perovskite single crystal is filtered out, the surface of the single crystal is polished with sandpaper, and after polishing, it is polished with sandpaper, and the polished single crystal is dried and further polished to obtain the final low-dimensional co-occupied perovskite single crystal ABX5 thin sheet.

9. A low-dimensional co-occupied perovskite single crystal prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The structural formula of the low-dimensional co-occupied perovskite single crystal is ABX5, wherein A is a large-sized organic 4-carboxamidinopyridinium cation, B is Sb m Bi 1-m , X is I, 0<m<1.

10. The low-dimensional co-occupied perovskite single crystal according to claim 9, characterized in that: The ABX5 is (4AP)Sb 0.75 Bi 0.25 I5、(4AP)Sb 0.55 Bi 0.45 I5 or (4AP)Sb 0.34 Bi 0.66 I5.

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