Lead-containing perovskite luminescent material and luminescent color gamut tuning method and application thereof

Abstract

The invention is suitable for perovskite luminescent materials, and provides a lead-containing perovskite luminescent material, the luminescent material is a one-dimensional hybrid lead bromide perovskite luminescent material, the chemical formula is (C6N10H8) Pb2Br6, and the preparation method comprises the following steps: dissolving lead acetate trihydrate and hexamethyl ammonium bromide in hydrobromic acid together; slowly heating in a methyl silicone oil bath, and stirring until a clear solution is formed to obtain a precursor solution; and cooling the precursor solution to room temperature to generate a colorless prismatic crystal, namely (C6N10H8) Pb2Br6. The invention further provides a method for tuning the light-emitting color gamut of the lead-containing perovskite light-emitting material. The invention also provides a multi-color-gamut-covered perovskite luminescent material and an application of the multi-color-gamut-covered perovskite luminescent material in preparation of photoelectric devices. According to the invention, pressure-induced FE emission is realized in one-dimensional (1D) hybrid lead bromide perovskite (C6N10H8) Pb2Br6 ((HM) Pb2Br6), accurate conversion from an ST-FE luminescence mechanism and effective tuning of a luminescence color gamut are realized, and the photoluminescence intensity of the material under fixed exciting light is improved.

Description

Technical Field

[0001] The present invention relates to perovskite luminescent materials, and in particular to a lead-containing perovskite luminescent material and a luminescent color gamut tuning method and application thereof. Background Art

[0002] Perovskite luminescent materials have attracted more and more attention in the fields of green energy, white light illumination, photoelectric sensors, etc. due to their excellent light absorption performance, large exciton binding energy and broadband emission. The wide spectrum emission characteristics of a single material can effectively compensate for a series of problems such as color difference caused by aging and attenuation of commercial multi-matrix phosphors. In view of this goal, it is extremely important to find and design methods to effectively tune the perovskite luminescence mechanism, so as to obtain efficient and stable perovskite luminescent materials covering multiple color domains and play a role in different scenarios, such as tunable lighting, external stimulus response, etc.

[0003] The prior art proposes that the proportion of different halogen atoms in perovskite materials can be adjusted by doping or chemical element gradient, thereby changing the band gap of the material and tuning the emission mechanism. However, the phase segregation and defects caused by different halogens during use lead to poor material stability and reduced photoluminescence quantum yield. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a lead-containing perovskite light-emitting material, aiming to solve the problems raised in the above-mentioned background technology.

[0005] The embodiment of the present invention is implemented as follows: a lead-containing perovskite luminescent material, wherein the luminescent material is a one-dimensional hybrid lead bromide perovskite luminescent material, and the chemical formula is (C6N 10 H8) Pb2Br6, the preparation method of which comprises the following steps:

[0006] ((1) Lead acetate trihydrate and hexamethylammonium bromide are dissolved in hydrobromic acid;

[0007] (2) slowly heating in a methyl silicone oil bath and stirring until a clear solution is formed to obtain a precursor solution;

[0008] (3) The precursor solution is cooled to room temperature to generate colorless prismatic crystals, namely (C6N 10 H8)Pb2Br6.

[0009] Preferably, in step (1), the molar ratio of lead acetate trihydrate to hexamethylammonium bromide is 1:1.

[0010] Preferably, in step (2), the clear solution is slowly heated to 120° C. in a methyl silicone oil bath.

[0011] Preferably, in step (3), the precursor solution is cooled to room temperature at a rate of 5°C / h.

[0012] Preferably, the (C6N 10 H8) Pb2Br6 is a micron-sized crystal with an initial monoclinic crystal structure. At room temperature and pressure, it has a single emission peak with a central wavelength of 691 nm, and the corresponding CIE chromaticity coordinates are (0.377, 0.348).

[0013] Another object of the embodiment of the present invention is to provide a method for tuning the luminous color gamut of a lead-containing perovskite luminescent material, comprising the following steps:

[0014] (1) Pre-pressing a stainless steel sheet using a diamond anvil press, and drilling a hole groove at the indentation as a pressure cavity;

[0015] (2) placing a sample of the lead-containing perovskite luminescent material into a pressure chamber, adding silicone oil as a pressure transmission medium, and pressurizing the chamber. Ruby is used as a pressure calibration material during the pressurization process. The pressure is increased from room temperature to 20 GPa.

[0016] Preferably, the sample of the lead-containing perovskite light-emitting material realizes a transition of the light-emitting mechanism from STE emission to FE emission during the pressurization process.

[0017] Another object of an embodiment of the present invention is to provide a perovskite light-emitting material with multi-color domain coverage, which is obtained by the above method.

[0018] Another object of the embodiments of the present invention is to provide a multi-color domain covered perovskite light-emitting material for use in preparing optoelectronic devices.

[0019] The embodiment of the present invention provides a method for tuning the luminescence color range of a lead-containing perovskite luminescent material, based on a one-dimensional (1D) hybrid lead bromide perovskite (C6N 10 Pressure-induced FE emission was achieved in H8)Pb2Br6 ((HM)Pb2Br6). The material exhibited weak broadband STE emission under ambient conditions. During the entire compression process, (HM)Pb2Br6 initially achieved a 42-fold STE emission enhancement. Subsequently, STE emission gradually transitioned to narrow emission. STE emission and FE emission coexisted, and the color changed from red to white and then to yellow. By using pressure as a clean means, the interatomic distance and interaction inside the material were precisely controlled without introducing other components, and the material band gap was changed. With the increase of pressure, [Pb2Br6] 2- The octahedron continues to shrink, and the electron-phonon coupling gradually decreases, achieving a precise transition from the STE-FE luminescence mechanism and effective tuning of the luminescence color range, thereby enabling the design of more valuable perovskite optoelectronic devices;

[0020] The material of the embodiment of the present invention is easy to prepare and stable, and there is a self-trapped exciton emission-free exciton emission transition phenomenon. The emission covers a wide color range at room temperature and pressure. The method of the embodiment of the present invention is used to improve the photoluminescence intensity of the material under fixed excitation light. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The X-ray diffraction pattern and atomic configuration diagram of the (HM)Pb2Br6 crystal sample provided in Example 1 of the present invention;

[0022] Figure 2 A working principle diagram of a device used in a method for tuning the luminescent color gamut of a lead-containing perovskite luminescent material provided in Example 2 of the present invention;

[0023] Figure 3 Fluorescence spectra of the (HM) Pb2Br6 crystal sample provided in Example 2 of the present invention at different pressures;

[0024] Figure 4 The (HM) Pb2Br6 crystal sample provided in Example 2 of the present invention is a free exciton emission spectrum at different pressures;

[0025] Figure 5 CIE chromaticity diagram and fluorescence micrograph of the (HM)Pb2Br6 crystal sample during the pressurization process provided in Example 2 of the present invention;

[0026] Figure 6 This is the fluorescence spectrum of the (HM)Pb2Br6 crystal sample provided in Example 3 of the present invention under 355nm excitation light and normal pressure. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0029] Example 1. A lead-containing perovskite luminescent material ((HM)Pb2Br6 crystal), prepared as follows: first, lead acetate trihydrate (Pb(Ac)2·3H2O) (1 mmol, 0.3793 g) and hexamethylammonium bromide (1 mmol, 0.3622 g) were dissolved in 6.5 mL 48 wt.% hydrobromic acid, and then heated in a methyl silicone oil bath at 120°C and stirred until a clear solution was formed to obtain a precursor solution. Finally, the precursor solution was cooled to room temperature at a rate of 5°C / h to generate colorless prismatic crystals, thereby obtaining a (HM)Pb2Br6 crystal sample.

[0030] Performance Testing:

[0031] The (HM) Pb2Br6 crystal sample prepared in Example 1 was fully ground in a mortar as a test sample, and an X-ray diffraction experiment was performed using a synchrotron radiation source (X-ray wavelength is 0.06199 nm). The results are as follows: Figure 1 As shown, according to Figure 1 It can be seen that the crystal structure of the sample is monoclinic.

[0032] Embodiment 2: A method for tuning the luminescence color range of a lead-containing perovskite luminescent material, such as Figure 2 As shown, the specific steps include:

[0033] (1) Using T301 stainless steel as the sealing metal gasket, first use a diamond anvil press with an anvil diameter of 400 μm to pre-press it to a thickness of 42-45 μm, and then use a drill to drill a hole with a diameter of 150 μm in the center of the pre-pressing position as the pressure cavity;

[0034] (2) A (HM) Pb2Br6 crystal sample with a diameter of 50-100 μm and a standard pressure material ruby ​​with a diameter of 2-5 μm are placed in a pressure cavity, and silicone oil with a viscosity coefficient of 10 cst is used as a pressure transmission medium to package the cavity, and the pressure is increased from room temperature to 20 GPa.

[0035] Performance Testing:

[0036] During the pressurization process, the in-situ optical property test of the sample was carried out simultaneously. Specifically, during the pressurization to 20 GPa, a 355 nm laser was used as the excitation light source, and the sample fluorescence signal was collected by an Ocean Optics QEPro spectrometer. The results are as follows: Figure 3 As shown in the figure, in the fluorescence peak of the (HM)Pb2Br6 perovskite sample, the fluorescence peak of the initial STE part first blue-shifts and then red-shifts. Figure 4 It can be seen that the FE emission fluorescence peak appears after the pressure of 4.1 GPa, and the FE part of the fluorescence peak continues to red-shift. Both fluorescence peaks first increase and then decrease during the pressurization process;

[0037] pass Figure 3 The fluorescence spectrum curves under different pressures are plotted to show the evolution trend of CIE chromaticity coordinates with pressure. Figure 5 As shown in a, the dotted arrow in the figure indicates the change trend. The fluorescence micrographs obtained during the pressurization process are shown in Figure 5 As shown in b;

[0038] There are no specific requirements for the metal gasket material and the diamond anvil surface used in the embodiments of the present invention. As long as the pressure can be applied to 20 GPa, the transition from self-trapped exciton luminescence to free exciton luminescence of the lead-containing perovskite luminescent material can be achieved.

[0039] Example 3: Using T301 stainless steel as a sealing metal gasket, first use a diamond anvil press with an anvil diameter of 400 μm to pre-press it to a thickness of 42-45 μm, and then use a drill to drill a hole with a diameter of 150 μm in the center of the pre-pressed position as a pressure cavity;

[0040] A (HM)Pb2Br6 crystal sample with a diameter of 50-100μm and a standard pressure material ruby ​​with a diameter of 2-5μm were placed in a pressure cavity, and silicone oil with a viscosity coefficient of 10cst was used as a pressure transmission medium to seal the cavity and pressurize it. During the pressurization to 20GPa, a 355nm laser was used as an excitation light to obtain the fluorescence spectrum of the (HM)Pb2Br6 perovskite crystal sample under normal pressure, as shown in FIG. Figure 6 shown.

[0041] 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A lead-containing perovskite luminescent material, characterized in that: The luminescent material is a one-dimensional hybrid lead bromide perovskite luminescent material, and the chemical formula is (C6N 10 H8) Pb2Br6, the preparation method of which comprises the following steps: (1) dissolving lead acetate trihydrate and hexamethylammonium bromide in hydrobromic acid; (2) slowly heating in a methyl silicone oil bath and stirring until a clear solution is formed to obtain a precursor solution; (3) The precursor solution is cooled to room temperature to generate colorless prismatic crystals, namely (C6N 10 H8)Pb2Br6.

2. The lead-containing perovskite luminescent material according to claim 1, characterized in that: In step (1), the molar ratio of lead acetate trihydrate to hexamethylammonium bromide is 1:

1.

3. The lead-containing perovskite luminescent material according to claim 1, characterized in that: In step (2), the clear solution is slowly heated to 120° C. in a methyl silicone oil bath.

4. The lead-containing perovskite luminescent material according to claim 1, characterized in that: In step (3), the precursor solution is cooled to room temperature at a rate of 5°C / h.

5. The lead-containing perovskite luminescent material according to claim 1, characterized in that: The (C6N 10 H8) Pb2Br6 is a micron-sized crystal with an initial monoclinic crystal structure. At room temperature and pressure, it has a single emission peak with a central wavelength of 691 nm, and the corresponding CIE chromaticity coordinates are (0.377, 0.348).

6. A method for tuning the luminescent color gamut of a lead-containing perovskite luminescent material as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Pre-pressing a stainless steel sheet using a diamond anvil press, and drilling a hole groove at the indentation as a pressure cavity; (2) placing a sample of the lead-containing perovskite luminescent material into a pressure chamber, adding silicone oil as a pressure transmission medium, and pressurizing the chamber. Ruby is used as a pressure calibration material during the pressurization process. The pressure is increased from room temperature to 20 GPa.

7. The method for tuning the luminous color gamut according to claim 6, characterized in that: The sample of the lead-containing perovskite luminescent material realizes a transition in the luminescence mechanism from STE emission to FE emission during the pressurization process.

8. A perovskite luminescent material with multi-color domain coverage, characterized in that: It is obtained by the method according to claim 6.

9. Use of the multi-color domain covered perovskite luminescent material as claimed in claim 8 in the preparation of optoelectronic devices.

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