A method for band gap regulation of manganese-doped two-dimensional perovskite

Abstract

The application belongs to the technical field of perovskite material preparation, and particularly relates to a method for regulating the band gap of two-dimensional manganese-doped perovskite, which comprises the following steps: step one: preparing Mn-doped PEA2PbBr4 perovskite; step two: under room temperature, adding hydrohalic acid into the Mn-doped PEA2PbBr4 perovskite obtained in step one, mixing and stirring to obtain Mn-doped PEA2PbBr4 perovskite after halogen ion exchange; and step three: grinding and blowing dry the Mn-doped PEA2PbBr4 perovskite after halogen ion exchange obtained in step two to remove unreacted hydrohalic acid solution. The method can adjust the light-emitting band gap of the Mn-doped PEA2PbBr4 perovskite at room temperature, and the photoluminescence efficiency and stability are good.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of perovskite material preparation, and particularly relates to a method for regulating the band gap of manganese-doped two-dimensional perovskite. BACKGROUND

[0002] Mn-doped two-dimensional perovskite has been widely concerned in recent years due to its excellent optical performance and thermal stability. Among them, Mn-doped PEA2PbBr4 with phenethyl as A site exhibits excellent photomagnetic performance.

[0003] Mn-doped PEA2PbBr4 perovskite (Mn: PEA2PbBr4) can radiate band edge exciton luminescence 415 nm and Mn orange luminescence 600 nm. The Mn orange luminescence is a result of energy transfer from the band edge exciton to the Mn d-d energy level. 4 T1 to 6 A1 radiates from the energy transfer of the band edge exciton to the Mn d-d energy level. By adjusting the doping concentration of Mn, the relative proportion of the two luminescence peaks can be effectively regulated, which is conducive to the application of the material in optoelectronic sensor devices. The patent document with publication number CN114574188A successfully induces the synthesis of Mn-doped PEA2PbBr4 perovskite at room temperature, solving the problem of obtaining Mn-doped PEA2PbBr4 perovskite by generally using high-temperature hot injection method.

[0004] However, in the prior art and the above-mentioned patent document CN114574188A, the luminescence band gap of Mn-doped PEA2PbBr4 perovskite is basically around this point of 415 nm. That is, in the prior art, the range value of the luminescence band gap of Mn-doped PEA2PbBr4 perovskite is small, which is difficult to meet different market demands. SUMMARY

[0005] The present application at least solves one of the above technical problems.

[0006] The technical problem to be solved by the present application is at least to provide a method for regulating the band gap of manganese-doped two-dimensional perovskite, which can adjust the luminescence band gap of Mn-doped PEA2PbBr4 perovskite at room temperature, and has good photoluminescence efficiency and stability.

[0007] To solve the above problems, the present application discloses a method for regulating the band gap of manganese-doped two-dimensional perovskite, comprising the following steps:

[0008] Step one: preparing Mn-doped PEA2PbBr4 perovskite;

[0009] Step two: under room temperature conditions, adding hydrohalic acid to the Mn-doped PEA2PbBr4 perovskite obtained in step one, mixing and stirring to obtain Mn-doped PEA2PbBr4 perovskite after halogen ion exchange;

[0010] Step three: grinding and drying the Mn-doped PEA2PbBr4 perovskite obtained in step two, and removing the unreacted hydrohalide acid solution.

[0011] Preferably, the preparation of the Mn-doped PEA2PbBr4 perovskite in step one comprises the following steps:

[0012] S1.1, adding powder solid PbBr2 into HBr solvent mixture, stirring until transparent to obtain PbBr2 precursor solution, and waiting at room temperature;

[0013] S1.2, adding powder solid MnBr2 into HBr solvent mixture, stirring until transparent to obtain MnBr2 precursor solution, and waiting at room temperature;

[0014] S1.3, mixing the MnBr2 precursor solution and the PbBr2 precursor solution at room temperature, making the two metal precursor solutions clear to obtain a precursor mixture, then adding solid PEABr powder into the precursor mixture, stirring, and stirring for 10 minutes to obtain the Mn-doped PEA2PbBr4 perovskite; grinding and drying the Mn-doped PEA2PbBr4 perovskite obtained, and removing the unreacted hydrohalide acid solution.

[0015] Preferably, in step S1.1, the ratio of PbBr2 to HBr solvent is 0.2 mmol:80 µL; in step S1.2, the ratio of MnBr2 to HBr solvent is 0.1 mmol:25 µL; the molar feeding ratio of Mn / Pb in the MnBr2 precursor solution and the PbBr2 precursor solution is 0.5:1; in step S1.3, the ratio of solid PEABr powder to precursor mixture is 0.025 g:105 µL.

[0016] Preferably, the hydrohalide acid is an HCl solution, and the volume and mass ratio of the HCl solution to the Mn-doped PEA2PbBr4 perovskite is 50-100 µL to 0.05 g.

[0017] Preferably, the hydrohalide acid is an HI solution, and the volume and mass ratio of the HI solution to the Mn-doped PEA2PbBr4 perovskite is 10-20 µL to 0.05 g.

[0018] Preferably, the concentration of the HBr, HCl and HI solution ranges from 30% to 50%.

[0019] Advantages of the present application

[0020] 1. The application first proposes to control the luminescence band gap of Mn-doped PEA2PbBr4 perovskite, and realizes the control of the luminescence band gap of Mn-doped PEA2PbBr4 perovskite by the method of the application, and solves the problem of narrow luminescence band gap of Mn-doped PEA2PbBr4 perovskite. Using the method of the application, Mn-doped PEA2PbX4 perovskite products with a luminescence band gap of 397 nm to 495 nm can be prepared according to actual needs.

[0021] 2. The method of the application can control the luminescence band gap of Mn-doped PEA2PbBr4 perovskite at room temperature, without the need for high-temperature injection, greatly saving energy, simple operation at room temperature, simple equipment, controllable process, low cost, conducive to the preparation of electroluminescent / photoluminescent white light LED, which can effectively promote the solid-state lighting and display application of two-dimensional Mn ion-doped perovskite materials, and is very conducive to production and manufacturing.

[0022] 3. The method of the application can effectively control the exciton luminescence and optical band gap of Mn-doped PEA2PbX4 perovskite through a simple acid-assisted post-processing synthesis method, and the process is simple. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The luminescence spectrum, Mn lifetime decay curve and quantum yield diagram of the products obtained in Comparative Example 1 and Examples 1-6 are shown.

[0024] Figure 2 The luminescence spectrum and Mn ion decay curve of the products obtained in Examples 7-10 are shown. 2+

[0025] Figure 3 The luminescence spectrum and lifetime decay curve of the products obtained in Example 1 and Example 11 are shown. DETAILED DESCRIPTION

[0026] ​The following description will describe the application concepts of the present disclosure using terminology generally used by those skilled in the art to convey the essence of their work to others skilled in the art. However, these application concepts can be embodied in many different forms, and thus should not be considered limited to the embodiments described herein. These embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the scope of the application to those skilled in the art. Note that these embodiments are not mutually exclusive. Components, steps, or elements from one embodiment can be assumed to be present or used in another embodiment. The specific embodiments shown and described are not intended to be limiting. Alternative and / or equivalent implementations are intended to be within the scope of the embodiments of the present disclosure. This application is intended to cover any modifications or variations of the embodiments discussed herein. It is apparent that alternative embodiments can be practiced without some of the specific aspects that are described. For the purpose of clarity, specific details are set forth in the description in order to provide a thorough understanding of the embodiments. However, alternative embodiments can be practiced without some of these specific details. In other instances, well-known features are not described in detail to avoid obscuring the embodiments shown and described.

[0027] A method of band gap tuning of manganese-doped two-dimensional perovskite, comprising the following steps:

[0028] Step one: preparation of Mn-doped PEA2PbBr4 perovskite:

[0029] S1.1, add powder solid PbBr2 to HBr solvent mixture, stir until transparent, obtain PbBr2 precursor solution, room temperature for use; the ratio of PbBr2 to HBr solvent is 0.2 mmol:80 µL;

[0030] S1.2, add powder solid MnBr2 to HBr solvent mixture, stir until transparent, obtain MnBr2 precursor solution, room temperature for use; the ratio of MnBr2 to HBr solvent is 0.1 mmol:25 µL;

[0031] S1.3, under room temperature conditions, mix the MnBr2 precursor solution and the PbBr2 precursor solution, make the two metal precursor solutions clear, obtain a precursor mixture, then add solid PEABr powder to the precursor mixture, stir for 10 minutes, obtain Mn-doped PEA2PbBr4 perovskite; grind and dry the obtained Mn-doped PEA2PbBr4 perovskite, remove the unreacted hydrogen halide acid solution; the Mn / Pb molar feeding ratio in the MnBr2 precursor solution and the PbBr2 precursor solution is 0.5:1, the ratio of solid PEABr powder to precursor mixture is 0.025 g:105 µL;

[0032] Step two: drop the hydrogen halide acid into the Mn-doped PEA2PbBr4perovskite obtained in step one under room temperature, mix and stir to obtain the halide ion exchanged Mn-doped PEA2PbBr4perovskite;

[0033] Step three: grind and dry the halide ion exchanged Mn-doped PEA2PbBr4perovskite obtained in step two to remove the unreacted hydrogen halide acid solution.

[0034] The hydrogen halide acid is HCl solution, and the volume and mass ratio of the HCl solution to the Mn-doped PEA2PbBr4perovskite is 50-100 µL to 0.05 g.

[0035] Of course, the hydrogen halide acid can also be HI solution, and the volume and mass ratio of the HI solution to the Mn-doped PEA2PbBr4perovskite is 10-20 µL to 0.05 g.

[0036] The concentration of the HBr, HCl and HI solution ranges from 30% to 50%.

[0037] The following will be described in more detail with the following examples, and the concentration of the HBr, HCl and HI solution in the following examples is 43%, 43% and 43% respectively.

[0038] In this application, room temperature specifically refers to 15°C to 30°C.

[0039] Comparative Example 1

[0040] Preparation of Mn-doped PEA2PbBr4perovskite:

[0041] S1.1: Mix 0.2 mmol of powder solid PbBr2and 80 µL of HBr liquid, stir to transparency at room temperature to obtain a PbBr2precursor solution, and wait at room temperature;

[0042] S1.2: Mix 0.1 mmol of powder solid MnBr2and 25 µL of HBr liquid, stir to transparency at room temperature to obtain a MnBr2precursor solution, and wait at room temperature;

[0043] S1.3: Mix the above PbBr2precursor solution and PbBr2precursor solution at room temperature to make the two metal precursor solutions clear to obtain a precursor mixture, then add 0.025 g of PEABr solid powder to the precursor mixture, stir for 10 minutes to obtain a Mn-doped PEA2PbBr4perovskite; grind and dry the obtained Mn-doped PEA2PbBr4perovskite to remove the unreacted hydrogen halide acid solution. Example

[0044] Step 1: Preparation of Mn-doped PEA2PbBr4 perovskite:

[0045] S1.1: Mix 0.2 mmol of solid PbBr2 powder and 80 µL of HBr liquid and stir at room temperature until transparent to obtain a PbBr2 precursor solution. Keep at room temperature for later use.

[0046] S1.2: Mix 0.1 mmol of powdered solid MnBr2 with 25 µL of liquid HBr and stir at room temperature until transparent to obtain a MnBr2 precursor solution. Keep at room temperature for later use.

[0047] S1.3: At room temperature, the PbBr2 precursor solution and the PbBr2 precursor solution are mixed to clarify the two metal precursor solutions to obtain a precursor mixture, and then 0.025 g of PEABr solid powder is added to the precursor mixture and stirred for 10 minutes to obtain Mn-doped PEA2PbBr4 perovskite; the obtained Mn-doped PEA2PbBr4 perovskite is ground and air-dried to remove unreacted hydrohalic acid solution;

[0048] Step 2: At room temperature, 100 μL of HCl solution was added dropwise to the Mn-doped PEA2PbBr4 perovskite obtained in step 1, and the mixture was stirred for 5 minutes to obtain the Mn-doped PEA2PbBr4 perovskite after halogen ion exchange.

[0049] Step 3: Grind and dry the Mn-doped PEA2PbBr4 perovskite obtained in step 2 after halogen ion exchange to remove unreacted hydrohalic acid solution.

[0050] The Mn-doped PEA2PbBr4 perovskite obtained after halogen ion exchange in this embodiment is Mn:PEA2PbCl 3.2 Br 0.8 . Example

[0051] The reaction conditions and steps were the same as those in Example 1, except that the amount of HCl solution in step 2 was 75 μL.

[0052] The Mn-doped PEA2PbBr4 perovskite obtained after halogen ion exchange in this embodiment is Mn:PEA2PbCl2Br2.

[0053] Example 3

[0054] The reaction conditions and steps were the same as those in Example 1, except that the amount of HCl solution in step 2 was 50 μL.

[0055] The Mn-doped PEA2PbBr4 perovskite obtained after halogen ion exchange in this embodiment is Mn:PEA2PbCl 1.5 Br2.5 .

[0056] Example 4

[0057] The reaction conditions and steps are the same as Example 1, except that in step two, 10 μL of HI solution was added dropwise to the Mn-doped PEA2PbBr4perovskite obtained in step one.

[0058] The halogen ion exchanged Mn-doped PEA2PbBr4perovskite obtained in this example is Mn:PEA2PbBr3I1.

[0059] Example 5

[0060] The reaction conditions and steps are the same as Example 1, except that in step two, 15 μL of HI solution was added dropwise to the Mn-doped PEA2PbBr4perovskite obtained in step one.

[0061] The halogen ion exchanged Mn-doped PEA2PbBr4perovskite obtained in this example is Mn:PEA2PbBr 2.2 I 1.8 .

[0062] Example 6

[0063] The reaction conditions and steps are the same as Example 1, except that in step two, 20 μL of HI solution was added dropwise to the Mn-doped PEA2PbBr4perovskite obtained in step one.

[0064] The halogen ion exchanged Mn-doped PEA2PbBr4perovskite obtained in this example is Mn:PEA2PbBr 0.8 I 3.2 .

[0065] Example 7

[0066] The reaction conditions and steps are the same as Example 6, except that the halogen ion exchanged Mn-doped PEA2PbBr4perovskite obtained was irradiated with UV light for 0.5 h.

[0067] Example 8

[0068] The reaction conditions and steps are the same as Example 6, except that the halogen ion exchanged Mn-doped PEA2PbBr4perovskite obtained was irradiated with UV light for 1 h.

[0069] Example 9

[0070] The reaction conditions and steps are the same as Example 6, except that the halogen ion exchanged Mn-doped PEA2PbBr4perovskite obtained was irradiated with UV light for 2 h.

[0071] Example 10

[0072] The reaction conditions and steps were the same as those in Example 6, except that the obtained halogen ion-exchanged Mn-doped PEA2PbBr4 perovskite was irradiated with UV light for 3 h.

[0073] Example 11

[0074] The reaction conditions and steps were the same as those in Example 1, except that the obtained halogen ion-exchanged Mn-doped PEA2PbBr4 perovskite was annealed at 420K for 30 minutes.

[0075] Figure 1 a. Figure 1 b are the luminescence spectra and Mn lifetime decay curves of the products obtained in Comparative Example 1 and Examples 1 to 6, respectively. Figure 1 a It can be seen that as the amount of HCl post-treatment increases, the exciton luminescence of the Mn-doped PEA2PbX4 perovskite blue-shifts, while as the amount of HI post-treatment continues to increase, the exciton luminescence of the Mn-doped PEA2PbX4 perovskite red-shifts. The exciton luminescence wavelength can be adjusted to 397nm to 495nm through post-treatment regulation of hydrohalic acid, successfully obtaining a two-dimensional Mn-doped PEA2PbX4 perovskite with adjustable bandgap. The bandgap regulation mentioned in this application refers to regulating the luminescence bandgap of the Mn-doped PEA2PbX4 perovskite. According to the method of this application, after adding HCl acid or HI acid in different proportions, Mn-doped PEA2PbX4 perovskite with a luminescence bandgap of 397nm to 495nm can be prepared accordingly, meeting market demand. This makes it possible to prepare Mn-doped PEA2PbBr4 perovskite with a luminescence bandgap of 397nm to 495nm, which is basically around 415nm in the prior art.

[0076] Figure 2 The luminescence spectra of the products obtained in Examples 7 to 10 and the Mn 2+ Ion decay curve. As can be seen from the figure, the exciton peak position of the Mn-doped PEA2PbBr4 perovskite post-treated with HI acid does not change significantly with increasing illumination time, and the Mn fluorescence lifetime is slightly extended, indicating that the I-based two-dimensional perovskite synthesized by this method has stable illumination characteristics.

[0077] Figure 3 The luminescence spectra and lifetime decay curves of the products obtained in Example 1 and Example 11 are shown in the figure. As can be seen from the analysis of the figure, after annealing at 420K, the luminescence spectrum at the 397nm peak does not fluctuate much, and the lifetime does not change much. This shows that the product obtained by the method of the present application has good thermal stability.

[0078] The above embodiments illustrate that the method of the present application is capable of regulating the luminescence band gap of Mn-doped PEA2PbBr4 perovskite at room temperature, without the need for high-temperature injection, which greatly saves energy. The operation is simple at room temperature, the equipment used is simple, the process is controllable, and the cost is low. It is conducive to the preparation of electro- / photo-induced white light LEDs, and can effectively promote the solid-state lighting and display applications of two-dimensional Mn ion-doped perovskite materials, which is very beneficial for production and manufacturing.

[0079] The method of the present application is to effectively control the exciton luminescence and optical band gap of Mn-doped PEA2PbX4 perovskite through a simple acid-assisted post-treatment synthesis method, and the process is simple.

[0080] The above description is merely a preferred and feasible implementation example of this application and does not limit the scope of the present application. For those skilled in the art, any other corresponding changes made using the technical solutions and technical concepts of this application should fall within the scope of protection of the claims of this application.

Claims

1. A method of bandgap engineering of a manganese-doped two-dimensional perovskite, characterized in that, Comprising the following steps: Step one: preparation of Mn-doped PEA2PbBr4 perovskite; Step two: under room temperature, drop halogen acid into the Mn-doped PEA2PbBr4 perovskite obtained in step one, mix and stir to obtain halogen ion exchanged Mn-doped PEA2PbBr4 perovskite; Step three: grind and dry the halogen ion exchanged Mn-doped PEA2PbBr4 perovskite obtained in step two to remove unreacted halogen acid solution; The preparation of Mn-doped PEA2PbBr4 perovskite in step one comprises the following steps: S1.1, add powder solid PbBr2 into HBr solvent and mix, stir until transparent to obtain PbBr2 precursor solution, and wait at room temperature; S1.2, add powder solid MnBr2 into HBr solvent and mix, stir until transparent to obtain MnBr2 precursor solution, and wait at room temperature; S1.3, under room temperature, mix the MnBr2 precursor solution and the PbBr2 precursor solution to make the two metal precursor solutions clear, then add solid PEABr powder into the precursor mixed solution, stir to obtain Mn-doped PEA2PbBr4 perovskite; grind and dry the obtained Mn-doped PEA2PbBr4 perovskite to remove unreacted halogen acid solution; In step S1.1, the ratio of PbBr2 to HBr solvent is 0.2 mmol:80 µL; in step S1.2, the ratio of MnBr2 to HBr solvent is 0.1 mmol:25 µL; the molar feeding ratio of Mn / Pb in the MnBr2 precursor solution and the PbBr2 precursor solution is 0.5:1; in step S1.3, the ratio of solid PEABr powder to precursor mixed solution is 0.025 g:105 µL.

2. The method of claim 1, wherein, The halogen acid is HCl solution, and the volume and mass ratio of the HCl solution to the Mn-doped PEA2PbBr4 perovskite is 50-100 µL to 0.05 g.

3. The method of claim 2, wherein, The concentration of the HBr and HCl solutions ranges from 30% to 50%.

4. The method of claim 1, wherein, The halogen acid is HI solution, and the volume and mass ratio of the HI solution to the Mn-doped PEA2PbBr4 perovskite is 10-20 µL to 0.05 g.

5. The method of claim 4, wherein, The concentration of the HBr and HI solutions ranges from 30% to 50%.

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