Preparation method of ion-doped metal halide perovskite CsPbX3

Abstract

The invention discloses a preparation method of ion-doped metal halide perovskite CsPbX3, and relates to the technical field of photoelectric materials.The preparation method comprises the steps that S1, CsX powder and PbX2 powder are subjected to ball milling and uniform mixing according to the molar ratio of 1: 1, and after ball milling, the powder is taken out and sieved to obtain mixed powder; wherein the ball milling time is 1-10 min, no ball milling medium exists, and the ball milling rotating speed is 50-100 rpm; s2, the mixed powder obtained in the step S1 and metal powder A are subjected to ball milling according to the proportion and mixed to be uniform, and A-doped Cs (Pb, A) X3 powder is obtained after ball milling; wherein the ball milling time is 5-10 h, no ball milling medium exists, and the ball milling rotating speed is 200-300 rpm; and S3, the Cs (Pb, A) X3 powder obtained in the S2 is subjected to heat preservation for 1-5 h in air at the temperature of 40-50 DEG C, and the Cs (Pb, A) X3 material doped with the A ions is obtained. The high-stability ion-doped Cs (Pb, A) X3 material is prepared by innovatively adopting an all-solid-state mechanochemical method, and the problem of poor stability of metal halide perovskite CsPbX3 is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic materials, and in particular to an ion-doped metal halide perovskite CsPbX 3 Preparation method. Background Art

[0002] Metal halide perovskite materials CsPbX 3 (X=Cl, Br, I) has become a hot material in the field of luminescence due to its ultra-high photoluminescence efficiency, tunable luminescence wavelength and ultra-narrow luminescence peak half-width. It is widely used in optoelectronic devices such as white light illumination, light-emitting diodes, solar cells, and photodetectors. In the past decade, the energy conversion efficiency of photovoltaic power generation components based on metal halide perovskites has been increased to more than 23%. CsPbX 3 Although it has low preparation cost, excellent performance, great application prospects and market value, its crystal structure stability is poor and it will degrade to varying degrees in light, heat and air, which seriously limits its commercial use.

[0003] Currently used to improve CsPbX 3 The first method is to use surface coating such as Si, SiO 2 , macromolecules and other materials to isolate it from the influence of the external environment, thereby improving stability. However, the above methods are mainly coated by solution method. Due to the ionic characteristics of perovskite, the selection of solvents is relatively difficult, especially polar solvents have a greater destructive effect on it. In addition, the solution method preparation is easy to introduce impurities, requiring a more complicated post-processing process, and will cause pollution to the environment.

[0004] Patent "CN108389976B" reports a method for preparing an organic-inorganic hybrid perovskite solar cell doped with a small amount of rare earth metal ions. The prepared rare earth metal ion-doped perovskite solar cell has long-term stability. The rare earth metal ion-doped perovskite photoactive layer is prepared by a solution co-precipitation method.

[0005] Patent "CN114574200B" reports a transition metal ion-doped perovskite quantum dot material and a preparation method thereof, wherein a precursor solution is prepared using a transition metal halide as a raw material, and the transition metal ion-doped perovskite material is prepared by a solution co-precipitation method.

[0006] The above-mentioned prior arts all have the problem of using precursor conversion, long preparation process cycle, and the co-precipitation method is often used for small batch tests, which makes it difficult to efficiently prepare kilograms of perovskite materials.

[0007] Another way to improve CsPbX 3The method of stabilization is to use element doping, using metal ions with smaller ionic radius to partially replace CsPbX 3 The Pb ions in the 6 ] 4- (A is the doping element), which can effectively improve the ion radius mismatch problem caused by the smaller radius of Cs ions and improve the crystal structure stability of all-inorganic perovskite materials. Summary of the invention

[0008] The present invention aims to provide an ion-doped metal halide perovskite CsPbX 3 The preparation method innovatively adopts all-solid-state mechanochemical method to prepare high-stability ion-doped Cs(Pb,A)X 3 Materials, effectively solving the metal halide perovskite CsPbX 3 (X=Cl, Br, I) has the problem of poor stability. To achieve the above object, the present invention provides the following technical solution:

[0009] The present invention provides an ion-doped metal halide perovskite CsPbX 3 A preparation method comprising the following steps:

[0010] Step S1: CsX powder and PbX 2 The powders are ball-milled and mixed uniformly at a molar ratio of 1:1, and then taken out and sieved to obtain a mixed powder; wherein the ball-milling time is 1 to 10 minutes, there is no ball-milling medium, and the ball-milling speed is 50 to 100 rpm;

[0011] Step S2: The mixed powder obtained in step S1 and the metal powder A are ball-milled in proportion to be uniformly mixed, and after ball milling, A-doped Cs(Pb,A)X 3 Powder; wherein the ball milling time is 5 to 10 hours, there is no ball milling medium, and the ball milling speed is 200 to 300 rpm;

[0012] Step S3: Cs(Pb,A)X obtained in step S2 3 The powder is kept in air at 40-50℃ for 1-5h to obtain A-doped Cs(Pb,A)X 3 Material.

[0013] Furthermore, X is one of Cl, Br or I.

[0014] Furthermore, in step S1, the purity of the CsX powder is ≥99.9wt.%, and the particle size is micrometer level; 2 The purity of the powder is ≥99.9wt.%, and the particle size is micron level.

[0015] Furthermore, in step S1, the ball-to-material ratio during ball milling is 4:1 to 10:1.

[0016] Furthermore, in step S1, the ball-to-material ratio during ball milling is 4:1, 6:1, 8:1 or 10:1.

[0017] Furthermore, in step S2, the metal powder A comprises Al or Mg powder, with a purity of ≥99wt.%, and a particle size of micrometer level.

[0018] Furthermore, in step S2, the atomic ratio of the metal powder A to Pb in the mixed powder is 1:100 to 10:100.

[0019] Furthermore, in step S2, the ball-to-material ratio during ball milling is 4:1 to 10:1.

[0020] Furthermore, in step S2, the ball-to-material ratio during ball milling is 4:1, 6:1, 8:1 or 10:1.

[0021] Technical effects and advantages of the present invention:

[0022] (1) The present invention adopts an all-solid-state mechanochemical method to prepare Cs(Pb,A)X 3 Materials, different from the conventional solution method to prepare ion-doped Cs(Pb,A)X 3 The material does not require the use of polar solvents, the post-processing is simple, and it does not cause pollution to the environment. The prepared Cs(Pb,A)X 3 The material is of high purity.

[0023] (2) The ion-doped Cs(Pb,A)X prepared by the mechanochemical method of the present invention 3 The material has a short preparation time and a simple process, and can efficiently prepare Cs(Pb,A)X 3 Material.

[0024] (3) The present invention is conducive to the optimization design of Cs(Pb,A)X 3 The composition content of element A in the composition, the molar content of element A is 0.01~0.1.

[0025] (4) Cs(Pb,A)X prepared by the present invention 3 The material particle size distribution is controllable and the structural stability is high.

[0026] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is an ion-doped metal halide perovskite CsPbX 3 Flow chart of the preparation method;

[0028] Figure 2 The Al-doped Cs(Pb 1 Al 0.1 )Br 3 XRD spectrum of

[0029] Figure 3 The Al-doped Cs(Pb 1 Al 0.1 )Br 3 SEM morphology of

[0030] Figure 4 The Al-doped Cs(Pb 1 Al 0.1 )Br 3 EDS element distribution map. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In order to solve the deficiencies of the prior art, the present invention discloses an ion-doped metal halide perovskite CsPbX 3 The preparation method of Figure 1 The present invention is an ion-doped metal halide perovskite CsPbX 3 The preparation method flow chart is as follows: Figure 1 As shown, the method comprises the following steps:

[0033] Step S1: CsX powder and PbX 2 The powders are mixed evenly in a planetary ball mill according to a certain ratio. The ball mill is made of polytetrafluoroethylene and the ball is made of agate (≥97.3wt.%SiO 2 During the ball milling process, inert gas (nitrogen) is introduced for protection, the ball milling time is 1 to 10 minutes, there is no ball milling medium, the ball milling speed is 50 to 100 rpm, and after ball milling, the mixed powder is taken out and sieved to obtain the mixed powder.

[0034] In step S1 of the present invention: X is one of Cl, Br or I. The purity of the CsX powder is ≥99.9wt.%, and the particle size is micrometer level.2 The purity of the powder is ≥99.9wt.%, and the particle size is micron-level. 2 The molar ratio of the powder is 1: 1. The ball-to-material ratio during ball milling is 4: 1 to 10: 1, preferably 4: 1, 6: 1, 8: 1 or 10: 1, and more preferably 6: 1.

[0035] Step S2: The mixed powder obtained in step S1 and the metal powder A are mixed uniformly by ball milling in a planetary ball mill according to a certain proportion. Inert gas (nitrogen) is introduced during the ball milling process for protection. The ball milling time is 5 to 10 hours, there is no ball milling medium, and the ball milling speed is 200 to 300 rpm. After ball milling, A-doped Cs(Pb,A)X 3 powder.

[0036] In step S2 of the present invention: the metal powder A includes but is not limited to Al or Mg powder, with a purity of ≥99wt.%, and a particle size of micrometer level. The atomic ratio of the metal powder A to the Pb in the mixed powder is 1:100 to 10:100. The ball-to-material ratio during the ball milling is 4:1 to 10:1, preferably 4:1, 6:1, 8:1 or 10:1; more preferably 6:1.

[0037] Step S3: Cs(Pb,A)X obtained in step S2 3 The powder is kept in air at 40-50℃ for 1-5h to achieve the purpose of pre-oxidation of the material, so as to obtain highly stable A-ion-doped Cs(Pb,A)X 3 Material.

[0038] In step S3 of the present invention: by high-energy ball milling, element A is dissolved into CsPbX 3 lattice, forming Cs(Pb,A)X 3 The selected A element is Al or Mg, which is easily oxidized in the air to form stable oxides. Therefore, in the synthesis of Cs(Pb,A)X 3 After that, Cs(Pb,A)X containing A element 3 It also has a strong ability to bind oxygen. After pre-oxidation at medium and low temperatures (40-50°C), a small amount of oxygen diffuses and dissolves into Cs(Pb,A)X 3 , which makes it show high stability in subsequent heating and cooling cycle experiments.

[0039] Embodiment 1:

[0040] Example 1 of the present invention discloses an ion-doped metal halide perovskite CsPbX 3 A preparation method comprising the following steps:

[0041] Step S1: CsBr powder and PbBr2 The powders were evenly mixed by ball milling in a common planetary ball mill at a molar ratio of 1:1. The ball milling time was 5 minutes, there was no ball milling medium, the ball milling speed was 100 rpm, the ball-to-material ratio during ball milling was 6:1, and the mixed powder was taken out and sieved after ball milling to obtain the mixed powder.

[0042] Step S2, the mixed powder is mixed with Al powder, the atomic ratio of Al element content to Pb element is 10:100. The ball milling time is 5 hours, there is no ball milling medium, the ball milling speed is 250rpm, the ball to material ratio during ball milling is 6:1, and Al-doped Cs (Pb 1 Al 0.1 )Br 3 powder.

[0043] Step S3: Cs(Pb 1 Al 0.1 )Br 3 The powder was kept in air at 50℃ for 5h to obtain highly stable Cs(Pb 1 Al 0.1 )Br 3 Material.

[0044] Figure 2 The Al-doped Cs(Pb 1 Al 0.1 )Br 3 XRD (X-ray diffraction) spectrum, such as Figure 2 As shown in the figure, the powder contains Cs(Pb,Al)Br 3 phase, indicating that after high-energy ball milling, the added Al was dissolved into CsPbBr 3 Form a solid solution.

[0045] Figure 3 The Al-doped Cs(Pb 1 Al 0.1 )Br 3 SEM (scanning electron microscope) morphology, such as Figure 3 As shown, the figure shows that the powder particle size distribution is uniform, the powder size is 20μm, and the surface is smooth.

[0046] Figure 4 The Al-doped Cs(Pb 1 Al 0.1 )Br 3 EDS (energy dispersive spectrometer) element distribution diagram, such as Figure 4 As shown in the figure, the powder contains Cs, Pb, Al, Br and O, and the elements are evenly distributed, which further proves that Al element is dissolved into CsPbBr 3At the same time, the powder also contains solid-dissolved O element, which is introduced during the pre-oxidation process and can improve the stability of the material.

[0047] The prepared Cs(Pb 1 Al 0.1 )Br 3 The material has a single phase, solid solution structure, and a particle size distribution of about 20 μm. After a heating and cooling cycle at 200°C, the material's crystal structure does not decompose.

[0048] Embodiment 2:

[0049] Example 2 of the present invention discloses an ion-doped metal halide perovskite CsPbX 3 A preparation method comprising the following steps:

[0050] Step S1: CsBr powder and PbBr 2 The powders were evenly mixed by ball milling in a common planetary ball mill at a molar ratio of 1:1. The ball milling time was 5 minutes, there was no ball milling medium, the ball milling speed was 100 rpm, the ball-to-material ratio during ball milling was 6:1, and the mixed powder was taken out and sieved after ball milling to obtain the mixed powder.

[0051] Step S2, the mixed powder is mixed with Mg powder, the atomic ratio of Mg element content to Pb element is 10:100. The ball milling time is 5 hours, there is no ball milling medium, the ball milling speed is 250rpm, the ball to material ratio during ball milling is 6:1, and Mg-doped Cs (Pb 1 Mg 0.1 )Br 3 powder.

[0052] Step S3: Cs(Pb 1 Mg 0.1 )Br 3 The powder was kept in air at 50℃ for 5h to obtain highly stable Cs(Pb 1 Mg 0.1 )Br 3 Material.

[0053] The prepared Cs(Pb 1 Mg 0.1 )Br 3 The material has a single phase, solid solution structure, and a particle size distribution of about 20 μm. After a heating and cooling cycle at 200°C, the material's crystal structure does not decompose.

[0054] Embodiment 3:

[0055] Example 3 of the present invention discloses an ion-doped metal halide perovskite CsPbX 3 A preparation method comprising the following steps:

[0056] Step S1: CsI powder and PbI 2 The powders were evenly mixed by ball milling in a common planetary ball mill at a molar ratio of 1:1. The ball milling time was 5 minutes, there was no ball milling medium, the ball milling speed was 100 rpm, the ball-to-material ratio during ball milling was 6:1, and the mixed powder was taken out and sieved after ball milling to obtain the mixed powder.

[0057] Step S2, the mixed powder is mixed with Al powder, the atomic ratio of Al element content to Pb element is 5:100. The ball milling time is 10 hours, there is no ball milling medium, the ball milling speed is 250rpm, the ball-to-material ratio during ball milling is 6:1, and Al-doped Cs (Pb 1 Al 0.05 )I 3 powder.

[0058] Step S3: Cs(Pb 1 Al 0.05 )I 3 The powder was kept in air at 40℃ for 5h to obtain highly stable Cs(Pb 1 Al 0.05 )I 3 Material.

[0059] The prepared Cs(Pb 1 Al 0.05 )I 3 The powder has a single phase, solid solution structure, and a particle size distribution of about 200nm. After a heating and cooling cycle at 200°C, the material's crystal structure does not decompose.

[0060] Embodiment 4:

[0061] Example 4 of the present invention discloses an ion-doped metal halide perovskite CsPbX 3 A preparation method comprising the following steps:

[0062] Step S1: CsCl powder and PbCl 2 The powders were evenly mixed by ball milling in a common planetary ball mill at a molar ratio of 1:1. The ball milling time was 5 minutes, there was no ball milling medium, the ball milling speed was 100 rpm, the ball-to-material ratio during ball milling was 6:1, and the mixed powder was taken out and sieved after ball milling to obtain the mixed powder.

[0063] Step S2, the mixed powder is mixed with Al powder, the atomic ratio of Al element content to Pb element is 1:100. The ball milling time is 7h, there is no ball milling medium, the ball milling speed is 250rpm, the ball to material ratio during ball milling is 6:1, and Al-doped Cs (Pb 1 Al 0.01 )Cl 3 powder.

[0064] Step S3: Cs(Pb 1 Al 0.01 )Cl 3 The powder was kept in air at 50℃ for 5h to obtain highly stable Cs(Pb 1 Al 0.01 )Cl 3 Material.

[0065] The prepared Cs(Pb 1 Al 0.01 )Cl powder has a single phase, solid solution structure, and a particle size distribution of about 400nm. After heating and cooling cycles at 200℃, the crystal structure of the material does not decompose.

[0066] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an ion-doped metal halide perovskite CsPbX3, characterized in that: The method comprises the following steps: Step S1, CsX powder and PbX2 powder are ball-milled and mixed evenly at a molar ratio of 1:1, and the mixed powder is taken out and sieved after ball milling to obtain a mixed powder; wherein the ball milling time is 1 to 10 minutes, there is no ball milling medium, and the ball milling speed is 50 to 100 rpm; Step S2, ball-milling the mixed powder obtained in step S1 and metal powder A in proportion to obtain A-doped Cs(Pb,A)X3 powder; wherein the ball-milling time is 5 to 10 hours, there is no ball-milling medium, and the ball-milling speed is 200 to 300 rpm; Step S3, keeping the Cs(Pb, A)X3 powder obtained in step S2 in air at 40-50°C for 1-5 hours to obtain A ion-doped Cs(Pb, A)X3 material.

2. The method for preparing an ion-doped metal halide perovskite CsPbX3 according to claim 1, characterized in that: The X is one of Cl, Br or I.

3. The method for preparing an ion-doped metal halide perovskite CsPbX3 according to claim 1 or 2, characterized in that: In step S1, the purity of the CsX powder is ≥99.9wt.%, and the particle size is micron-level; the purity of the PbX2 powder is ≥99.9wt.%, and the particle size is micron-level.

4. The method for preparing an ion-doped metal halide perovskite CsPbX3 according to claim 1, characterized in that: In step S1, the ball-to-material ratio during ball milling is 4:1 to 10:

1.

5. The method for preparing an ion-doped metal halide perovskite CsPbX3 according to claim 1, characterized in that: In step S1, the ball-to-material ratio during ball milling is 4:1, 6:1, 8:1 or 10:

1.

6. The method for preparing an ion-doped metal halide perovskite CsPbX3 according to claim 1, characterized in that: In step S2, the metal powder A includes Al or Mg powder, with a purity of ≥99wt.%, and a particle size of micron level.

7. A method for preparing an ion-doped metal halide perovskite CsPbX3 according to claim 1, 5 or 6, characterized in that: In step S2, the atomic ratio of the metal powder A to Pb in the mixed powder is 1:100 to 10:

100.

8. The method for preparing an ion-doped metal halide perovskite CsPbX3 according to claim 1, characterized in that: In step S2, the ball-to-material ratio during ball milling is 4:1 to 10:

1.

9. The method for preparing an ion-doped metal halide perovskite CsPbX3 according to claim 1, characterized in that: In step S2, the ball-to-material ratio during ball milling is 4:1, 6:1, 8:1 or 10:1.

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