An alkali-doped perovskite single crystal material, a preparation method and application thereof
By introducing high concentrations of alkali metal halide salts into the aqueous perovskite precursor, alkali metal-doped perovskite single crystals were prepared using a cooling method. This solved the stability and spectral emission problems of large-size all-inorganic perovskite single crystal materials, achieving broad-spectrum emission and low-cost preparation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING INST OF TECH
- Filing Date
- 2022-06-17
- Publication Date
- 2026-05-29
AI Technical Summary
Existing technologies make it difficult to prepare large-size, stable, and low-cost all-inorganic perovskite single crystal materials, and their emission wavelengths cannot achieve broad-spectrum emission.
A high concentration of alkali metal halide salts was introduced into a perovskite aqueous precursor, and alkali metal-doped perovskite single crystals were precipitated by a cooling method. The material with the chemical formula AaC1-aB2X5 was used, where A was selected from NH2CHNH2+, CH3NH3+, Cs+, B was selected from Pb2+, Cd2+, Mn2+, Zn2+, Sn2+, Ge2+, C was selected from Li+, Na+, K+, Rb+, X was selected from carboxylate ions and halide anions, and a was 0.01 to 0.3. The preparation process included dissolving the raw materials and cooling to room temperature to form single crystals.
Centimeter-sized alkali metal-doped CsPb2Br5 single crystals were prepared, with fluorescence spectra covering the visible and near-infrared light bands, achieving broad-spectrum emission. Moreover, the preparation method is simple and low-cost.
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Figure CN117286573B_ABST
Abstract
Description
Technical Field
[0001] This application relates to an alkali metal-doped perovskite single crystal material, its preparation method, and its application, belonging to the display field. Background Technology
[0002] In recent years, low-dimensional perovskite materials have attracted widespread attention from researchers due to their large Stokes shift and broad-spectrum emission characteristics. Perovskite materials with broad-spectrum emission have important applications in future X-ray imaging, white light solid-state illumination, and fluorescence concentrators. Various two-dimensional layered organic-inorganic hybrid perovskites with broad-spectrum emission have been reported, but their stability is poor. Recently, all-inorganic perovskites with broad-spectrum emission have also been reported, but they are generally small-sized single crystals or polycrystalline powders, and their preparation methods are complex and the raw materials are expensive. All-inorganic cesium lead bromine (CsPbBr3) perovskite has good stability, but its emission band is around 520 nm, which cannot achieve broad-spectrum emission. From a practical perspective, there is an urgent need to develop novel large-sized single-crystal all-inorganic perovskite materials with broad-spectrum emission and corresponding simple and low-cost preparation methods. Summary of the Invention
[0003] This invention proposes a method for preparing alkali metal-doped perovskite CsPb₂Br₅ single crystals. The key lies in introducing a high concentration of alkali metal halide salts into the aqueous perovskite precursor, followed by precipitation of the alkali metal-doped perovskite single crystals via a cooling method. Traditional cesium lead bromide perovskites emit light in the vicinity of 520 nm, failing to achieve broad-spectrum emission. This method can prepare centimeter-scale CsPb₂Br₅ perovskite single crystals with broad-spectrum emission. Test results show that the fluorescence spectrum of the alkali metal-doped CsPb₂Br₅ single crystals covers the visible and near-infrared light bands (500–1000 nm). The technical solution adopted in this invention is as follows:
[0004] An alkali metal-doped perovskite single crystal material, wherein the chemical formula of the alkali metal-doped perovskite single crystal material is A. a C 1-a B2X5;
[0005] Wherein, A is selected from NH2CHNH2 + CH3NH3 + Cs + At least one of them; B is selected from Pb 2+ Cd 2+ Mn 2+ Zn 2+ Sn 2+ 、Ge 2+ At least one of them; C is selected from Li + Na + K + Rb +At least one of the following; X is selected from at least one of carboxylate group and halide anion;
[0006] The value of a is 0.01 to 0.3.
[0007] Optionally, the size of the alkali metal-doped perovskite single crystal material is 0.1 to 10 cm.
[0008] Optionally, the metal-doped perovskite single crystal material emits a spectrum covering 500–1000 nm under light irradiation at 150–450 nm.
[0009] This application also proposes a method for preparing the above-mentioned alkali metal-doped perovskite single crystal material, comprising the following steps:
[0010] Step 1) Dissolve the raw materials containing AX, BX2, and CX in a solvent and dissolve them at a temperature of 50–90°C to obtain a precursor solution;
[0011] The concentration of CX in the precursor solution is 3M to 12M; the concentration of AX is 0.001M to 0.1M; and the concentration of BX2 is 0.001M to 0.1M.
[0012] Step 2) The precursor solution obtained in Step 1) is cooled to room temperature at a cooling rate of 10 to 0.1 °C / h, and crystals precipitate to form the alkali metal-doped perovskite single crystal material.
[0013] Optionally, the precursor solution obtained in step 1) is filtered.
[0014] Optionally, the filtration process involves filtering the precursor solution using a 0.22μm to 0.45μm filter head.
[0015] Optionally, the filtration process involves filtering the precursor solution using a 0.22 μm filter head.
[0016] Optionally, in step 2), the precursor solution is stabilized at 70℃~95℃ for 4~24h.
[0017] Optionally, in step 2), the precursor solution is stabilized at 95°C for 12 hours.
[0018] Optionally, the solvent is water.
[0019] Optionally, the cooling rate is 10 to 0.1 °C / h.
[0020] Optionally, the cooling rate is 2°C / h.
[0021] Optionally, the molar ratio of AX to BX2 is 1:0.1 to 1:10, and the molar ratio of AX to CX is 1:50 to 1:200.
[0022] This application also proposes the application of the above-mentioned alkali metal-doped perovskite single crystal materials in displays.
[0023] The beneficial effects that this application can produce include:
[0024] The method of this application introduces a high concentration of alkali metal halide salts into an aqueous perovskite precursor, and then precipitates alkali metal-doped perovskite single crystals by a cooling method, easily obtaining crystals with a size on the centimeter scale. The alkali metal-doped CsPb₂Br₅ perovskite single crystals prepared by this invention have broad-spectral emission characteristics. Test results show that the fluorescence spectrum of the alkali metal-doped CsPb₂Br₅ perovskite single crystals covers the visible and near-infrared light bands. Attached Figure Description
[0025] Figure 1 A schematic diagram of the process for preparing alkali metal-doped perovskite single crystals;
[0026] Figure 2 Image of a Na-doped perovskite single crystal;
[0027] Figure 3 The absorption and emission spectra of Na-doped perovskite single crystals;
[0028] Figure 4 The emission spectrum is that of a Li-doped perovskite single crystal. Detailed Implementation
[0029] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0030] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0031] Example 1: Na-doped Cs 0.88 Na 0.12 Preparation of PbBr5 single crystals:
[0032] Figure 1 A method for preparing alkali metal-doped CsPb2Br5 perovskite single crystals is demonstrated. From left to right, the method shows the preparation of the aqueous perovskite precursor solution, the stabilization of the aqueous perovskite precursor solution, and the cooling growth of the perovskite single crystal.
[0033] First, 0.8 mmol PbBr2, 0.8 mmol CsBr, and 80 mmol NaBr were dissolved in 15 mL of deionized water and heated at 90 °C for 4 h until the solution became clear. The solution was then rapidly filtered using a 0.22 μm filter to obtain an aqueous perovskite precursor solution for single crystal growth. The prepared aqueous perovskite precursor solution was transferred to a temperature-controlled device and stabilized at 95 °C for 12 h. Finally, the solution was cooled to room temperature at a rate of 2 °C / h to prepare Na-doped CsPb2Br5 perovskite single crystals. The elemental solid content was determined using ICP-OES (inductively coupled plasma optical emission spectrometry) to confirm that the chemical formula of the prepared single crystal was Cs. 0.88 Na 0.12 PbBr5.
[0034] Figure 2 Cs prepared in Example 1 0.88 Na 0.12 The absorption and emission spectra of PbBr5 perovskite single crystals are shown in the figure. The shift between the absorption position and the emission peak of the perovskite single crystal is large, which is called the large Stokes shift. The emission spectrum covers 500–1000 nm, which is a broad spectrum emission. The PLQY of perovskite single crystals of this composition reaches 28.5%. Figure 3 The image shows the physical specimen of the single crystal obtained in Example 1. The specific dimensions are: length 13mm, width 6.5mm, and thickness 130μm.
[0035] Example 2 Na-doped Cs 0.98 Na 0.02 Preparation of PbBr5 single crystals:
[0036] In this example, the amount of NaBr used was 64 mmol, and the rest of the preparation method was the same as in Example 1. Large-sized Cs were also prepared. 0.98 Na 0.02 PbBr5 single crystal. Cs prepared in Example 2. 0.98 Na 0.02 The absorption and emission spectra of the PbBr5 perovskite single crystals are similar to those of Example 1, with the emission spectrum covering 500–1000 nm. The PLQY of the perovskite single crystals of this composition is 4.2%. The dimensions of the single crystals are: length 12 mm, width 5.6 mm, and thickness 123 μm.
[0037] Example 3 Na-doped Cs 0.7 Na 0.3 Preparation of PbBr5 single crystals:
[0038] In this example, the amount of NaBr used was 180 mmol, and the rest of the preparation method was the same as in Example 1. The Cs prepared in Example 3... 0.7 Na 0.3The absorption and emission spectra of the PbBr5 perovskite single crystals are similar to those of Example 1, with the emission spectrum covering 500–1000 nm. The PLQY of the perovskite single crystals of this composition is 35.2%. The dimensions of the single crystals are: length 13 mm, width 6.3 mm, and thickness 140 μm.
[0039] Example 4: Li-doped Cs 0.82 Li 0.18 Preparation of Pb2Br5 single crystals:
[0040] In this embodiment, NaBr was replaced with LiBr, and the rest of the preparation method was the same as in Example 1. Large-sized Li-doped Cs were also prepared. 0.82 Li 0.18 Pb₂Br₅ single crystal. Cs prepared in Example 4. 0.82 Li 0.18 The emission spectrum of Pb2Br5 perovskite single crystal is as follows: Figure 4 As shown, the emission spectrum covers 500–1000 nm, and the PLQY of the perovskite single crystal of this composition is 25.8%. The dimensions of the single crystal are: length 11.5 mm, width 5.8 mm, and thickness 131 μm.
[0041] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. An alkali metal-doped perovskite single crystal material, characterized in that, The chemical formula of the alkali metal-doped perovskite single crystal material is A. a C 1-a B2X5; Wherein, A is Cs + B is Pb 2+ C is selected from Li + Na + At least one of them; X is selected from halide anions; The halide anion is selected from Br; The value of a is 0.01 to 0.
3.
2. The alkali metal-doped perovskite single crystal material according to claim 1, characterized in that, The size of the alkali metal-doped perovskite single crystal material is 0.1~10 cm.
3. The alkali metal-doped perovskite single crystal material according to claim 1, characterized in that, The metal-doped perovskite single crystal material emits a spectrum covering 500–1000 nm under light irradiation of 150–450 nm.
4. The method for preparing the alkali metal-doped perovskite single crystal material according to any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1) Dissolve the raw materials containing AX, BX2, and CX in a solvent and dissolve them at a temperature of 50~90℃ to obtain a precursor solution; The concentration of CX in the precursor solution is 3M~12M; the concentration of AX is 0.001M~0.1M; and the concentration of BX2 is 0.001M~0.1M. Step 2) The precursor solution obtained in Step 1) is cooled to room temperature at a cooling rate of 10 ~ 0.1℃ / h, and crystals precipitate to form the alkali metal doped perovskite single crystal material.
5. The method according to claim 4, characterized in that, In step 1), the obtained precursor solution is filtered.
6. The method according to claim 5, characterized in that, The filtration process involves filtering the precursor solution using a 0.22 μm to 0.45 μm filter head.
7. The method according to claim 4, characterized in that, In step 2), the precursor solution is stabilized at 70℃~95℃ for 4~24 h.
8. The method according to claim 4, characterized in that, The solvent is water.
9. The method according to claim 4, characterized in that, The molar ratio of AX to BX2 is 1:0.1 to 1:10, and the molar ratio of AX to CX is 1:50 to 1:
200.
10. The application of any one of the alkali metal-doped perovskite single crystal materials according to claims 1 to 3, and the alkali metal-doped perovskite single crystal materials obtained by any one of the preparation methods according to claims 7 to 9, in displays.