A two-dimensional antimony-based metal halide perovskite fluorescent material and preparation method thereof

Abstract

The present invention discloses a two-dimensional antimony-based metal halide perovskite fluorescent material and its preparation method, belonging to the technical field of metal halide perovskite fluorescent powder. The present invention dissolves Sb2O3 in concentrated hydrochloric acid, then adds CsX to react; then adds MnX2·4H2O, CdX2 and CsX to continue the reaction, and after standing, washes, separates and dries to obtain Cs4Cd x Mn 1‑x Sb2X 12 ;X is one or more of Cl, Br, I, F elements, and x is 0.1-0.9. The present invention can synthesize photoluminescent Cs4Cd by the improved supersaturated recrystallization method at room temperature and pressure. x Mn 1‑x Sb2X 12 The prepared materials have finer particle size than those prepared by solvent thermal and hot injection methods, and have good crystallinity and stability to light and heat.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal halide perovskite phosphors, and in particular relates to a two-dimensional antimony-based metal halide perovskite fluorescent material and a preparation method thereof. Background Art

[0002] Halide perovskites have attracted considerable attention due to their high light absorption coefficient, long charge carrier diffusion length, low cost, and simple and diverse synthesis methods. They hold great potential for application in lighting sources, optoelectronic devices, and thermoelectric materials. However, the synthesis of metal halide perovskites using methods such as hot injection, solvothermal, solid-phase, and chemical methods has drawbacks such as large grain size and poor thermal stability. Therefore, finding suitable methods, enriching the synthesis strategies for two-dimensional halide perovskites, and improving the thermal stability of synthesized perovskites are crucial to achieving efficient luminescence from halide perovskites. Summary of the Invention

[0003] In view of the above shortcomings of the prior art, the present invention provides a two-dimensional antimony-based metal halide perovskite fluorescent material and a preparation method thereof.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing a two-dimensional antimony-based metal halide perovskite fluorescent material, comprising the following steps:

[0005] (1) Dissolve Sb2O3 in concentrated hydrochloric acid, then add CsX to react;

[0006] (2) Add MnX2·4H2O, CdX2 and CsX to continue the reaction. After standing, wash, separate and dry to obtain Cs4Cd x Mn 1-x Sb2X 12 ; X is one or more of Cl, Br, I, and F elements, and x is 0.1 to 0.9.

[0007] More preferably, the x is 0.1 to 0.5.

[0008] As a preferred embodiment of the present invention, the molar ratio of Sb2O3, MnX2·4H2O, CdX2 and CsX is 1:1-x:x:4.

[0009] As a preferred embodiment of the present invention, in step (1), the mass concentration ratio of Sb2O3 to concentrated hydrochloric acid is 290 mg:5 mL.

[0010] As a preferred embodiment of the present invention, the mass of CsX added in step (1) is 25% of the total mass of CsX in steps (1) and (2).

[0011] In step (1), Sb2O3 first reacts with part of CsX, which can shorten the synthesis time of the final two-dimensional antimony-based metal halide perovskite fluorescent material and effectively avoid the agglomeration between the particles of the two-dimensional antimony-based metal halide perovskite fluorescent material, forming uniformly dispersed particles. In addition, the present invention regulates the amount of oxygen vacancies generated by regulating the molar ratio of Sb2O3 to the part of CsX that reacts first, thereby improving the stability of the two-dimensional antimony-based metal halide perovskite fluorescent material. Finally, the present invention uses Sb2O3 instead of SbCl3 to prepare the perovskite fluorescent material, which can also appropriately increase the formation of oxygen vacancies, thereby achieving the purpose of thermal stability of the material.

[0012] As a preferred embodiment of the present invention, in step (1), the reaction time of adding CsX is 0.1 to 0.2 h.

[0013] As a preferred embodiment of the present invention, in step (2), the time for adding MnX2·4H2O, CdX2 and CsX to continue the reaction is 8 to 12 hours.

[0014] As a preferred embodiment of the present invention, in step (2), the standing time is 1 to 3 hours.

[0015] The present invention also claims to protect the Cs4Cd prepared by the preparation method of the two-dimensional antimony-based metal halide perovskite fluorescent material. x Mn 1-x Sb2X 12 Materials: X is one or more of Cl, Br, I, and F elements, and x is 0.1 to 0.9.

[0016] As a preferred embodiment of the present invention, the chemical formula of the two-dimensional antimony-based metal halide perovskite fluorescent material is Cs4Cd x Mn 1-x Sb2X 12 , the crystal structure is hexagonal, the space group is R-3m, and the lattice constant

[0017] Compared with the prior art, the present invention has the following advantages: the present invention can synthesize photoluminescent Cs4Cd by an improved supersaturated recrystallization method at room temperature and pressure. x Mn 1-x Sb2X 12 The prepared materials have finer particle size than those prepared by solvent thermal and hot injection methods, and have good crystallinity and stability to light and heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The XRD patterns of the materials prepared in Example 1 and Comparative Example 1 are shown.

[0019] Figure 2 Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12 Materials and Cs4MnSb2Cl prepared in Comparative Example 1 12 SEM images and element distribution diagrams of the materials; (a) Cs4MnSb2Cl 12 ; (b) is Cs4Cd 0.8 Mn 0.2 Sb2Cl 12 ; (c) Cs4Cd 0.8 Mn 0.2 Sb2Cl 12 Individual particles at 10,000 times.

[0020] Figure 3 Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12 EDS spectrum of the material.

[0021] Figure 4 Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12 Excitation spectrum of the material at 620 nm.

[0022] Figure 5 Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12 Emission spectrum of the material under 351nm ultraviolet light excitation.

[0023] Figure 6 Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12 Materials and Cs4MnSb2Cl prepared in Comparative Example 1 12 Comparison of photoluminescence quantum yields of materials.

[0024] Figure 7 Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12 Thermogravimetric analysis of the material obtained by heating from 10℃ per minute to 600℃ in N2 atmosphere, among which Cs4Cd 0.8 Mn 0.2 Sb2Cl 12 Cs4Cd 0.8 Mn 0.2Sb2Cl 12 Thermogravimetric test of the sample one year ago; Cs4Cd 0.8 Mn 0.2 Sb2Cl 12 The thermogravimetric test results were obtained after storage at room temperature and pressure for one year.

[0025] In the figure, 0.0, = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 are x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 respectively. DETAILED DESCRIPTION

[0026] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0027] Example 1

[0028] A method for preparing a two-dimensional antimony-based metal halide perovskite fluorescent material comprises the following steps:

[0029] (1) Place 1 mmol of Sb2O3 in a 20 ml glass bottle, add 5 ml of concentrated hydrochloric acid and stir to dissolve evenly, then add 3 mmol of CsCl and stir to react for 0.1 h to form a colloidal suspension.

[0030] (2) 1-x mmolMnCl2·4H2O, xmmolCdCl2 (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0), and 1mmolCsCl were added to the colloidal suspension and the reaction was continued for 10 h. After standing for 2 h, the sample was washed with ethanol three times. The colloidal suspension was transferred to a 15 ml centrifuge tube and centrifuged for 7 min. The centrifuge tube was removed and the supernatant was discarded to obtain the sample. Finally, it was dried to obtain Cs4Cd x Mn 1-x Sb2Cl 12 ;x=0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0.

[0031] Example 2

[0032] The only difference between the preparation method of a two-dimensional antimony-based metal halide perovskite fluorescent material in this embodiment and that in Example 1 is that in step (2), the reaction time is 8 hours and the standing time is 3 hours.

[0033] Example 3

[0034] The only difference between the preparation method of a two-dimensional antimony-based metal halide perovskite fluorescent material in this embodiment and that in Example 1 is that: in step (1), the reaction time is 0.2 h; in step (2), the reaction time is 12 h and the standing time is 1 h.

[0035] Comparative Example 1

[0036] A method for preparing a two-dimensional antimony-based metal halide perovskite fluorescent material comprises the following steps:

[0037] (1) Place 1 mol% Sb2O3 in a 20 ml glass bottle, add 5 ml of concentrated hydrochloric acid and stir to dissolve evenly, then add 3 mol% CsCl and stir to form a colloidal suspension.

[0038] (2) 1 mol% MnCl2·4H2O and 1 mol% CsCl were added to the colloidal suspension and the reaction was continued for 10 h. After standing for 2 h, the sample was washed with ethanol three times. The colloidal suspension was transferred to a 15 ml centrifuge tube and centrifuged for 7 min. The centrifuge tube was removed and the supernatant was discarded to obtain the sample. Finally, it was dried to obtain Cs4MnSb2Cl 12 .

[0039] Comparative Example 2

[0040] A method for preparing a two-dimensional antimony-based metal halide perovskite fluorescent material comprises the following steps:

[0041] 1 mol% Sb2O3 was placed in a 20 ml glass bottle, 5 ml of concentrated hydrochloric acid was added and stirred to dissolve evenly, then 0.2 mol% MnCl2·4H2O, 0.8 mol% CdCl2 and 4 mol% CsCl were added and stirred evenly, and then the solvent thermal reaction was carried out at 160 ° C for 12 h, and then the sample was washed with ethanol 3 times, and the suspension was transferred to a 15 ml centrifuge tube and centrifuged for 7 min. The centrifuge tube was removed and the supernatant was discarded to obtain the sample, and finally dried to obtain Cs4Cd 0.8 Mn 0.2 Sb2Cl 12 .

[0042] Comparative Example 3

[0043] A method for preparing a two-dimensional antimony-based metal halide perovskite fluorescent material comprises the following steps:

[0044] (1) Place 1 mol% Sb2O3 in a 20 ml glass bottle, add 5 ml of concentrated hydrochloric acid and stir to dissolve evenly.

[0045] (2) Then, 0.2 mol% MnCl2·4H2O, 0.8 mol% CdCl2 and 4 mol% CsCl were added and stirred for 10 h. After standing for 2 h, the sample was washed with ethanol three times. The suspension was transferred to a 15 ml centrifuge tube and centrifuged for 7 min. The centrifuge tube was removed and the supernatant was discarded to obtain the sample. Finally, the sample was dried to obtain Cs4Cd 0.8 Mn 0.2 Sb2Cl 12 .

[0046] like Figure 1 As shown, the Cs4Cd prepared in Example 1 x Mn 1-x Sb2Cl 12 The XRD peaks of materials (x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0) are similar to those of Cs4MnSb2Cl 12 The standard PDF card is highly matched, indicating that the method of the present invention is successfully prepared Cs4Cd x Mn 1-x Sb2Cl 12 Perovskite materials.

[0047] like Figure 2 As shown, the Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12 Materials and Cs4MnSb2Cl prepared in Comparative Example 1 12 All of them are nanoparticles with irregular size and shape. Compared with the materials prepared by hydrothermal method and solvent thermal method, they have larger specific surface area and smaller diameter of synthesized grains ( Figure 2 c). EDS mapping shows that all elements are evenly distributed, with no obvious enrichment or segregation.

[0048] And according to Figure 3 It can be seen that the Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12 The content of different elements in the material is in good agreement with the actual feed ratio, indicating that it can be successfully synthesized and the synthesis process has good uniformity.

[0049] according to Figure 4 It can be seen that the PLE spectrum centered at 351 nm, when monitored at 620 nm, can show the Cs4Cd prepared in Example 1. 0.8 Mn 0.2 Sb2Cl 12The spectrum of the material has three excitation bands at 350nm, 440nm and 527nm. The 350nm excitation band is due to the 1S0→3P1 transition of Sb-Cl; the absorption bands at 440nm and 527nm are related to the Mn 2+ The self-selected spin-forbidden transitions can be attributed to 6 A2→ 4 T2, 6 A1→ 4 T1 transition, the latter is due to Mn 2+ Ion pairs with Cd 2+ As the concentration of ions increases, the intensity of the spectrum increases first and then decreases. 2+ When the ion concentration reaches 0.8, the excitation intensity is the largest, and then, Cd 2+ The further increase of ion concentration will reduce the luminescence intensity due to concentration quenching. 2+ The incorporation of ions has an impact on the matrix Cs4MnSb2Cl 12 The luminescence performance plays an important role, high content of Cd 2+ It plays a role in weakening the strong coupling effect between Mn-Mn pairs. At the same time, most of the energy released from the ground state by ultraviolet excitation will be absorbed by the high content of Cd 2+ The concentration blocks the migration to defects where non-radiative transition decay may occur, thus achieving efficient energy transfer and increasing the photoluminescence efficiency.

[0050] according to Figure 5 and 6 It can be seen that the Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12 The material emits orange-red light under 351nm ultraviolet light excitation, and its photoluminescence quantum yield is 29.6%, which is higher than that of Cs4MnSb2Cl prepared in Comparative Example 1. 12 The photoluminescence quantum yield of the material was increased by 23 times (PLQY = 1.29%).

[0051] The materials prepared in Examples 2-3 emit orange-red light under 351nm ultraviolet light excitation, while the Cs4MnSb2Cl prepared in Comparative Example 1 12 The material prepared in Comparative Example 2-3 emits orange-red light under 351nm ultraviolet light excitation.

[0052] according to Figure 7 It can be seen that the Cs4Cd prepared in Example 1 0.8 Mn 0.2 Sb2Cl 12Thermogravimetric data obtained from the material one year before and after storage at room temperature and pressure for one year showed the same trend. When the temperature was raised from room temperature to approximately 300°C, the sample remained unchanged without decomposition. Thermal decomposition began between 300°C and 450°C, then stabilized after 450°C, with a mass change of approximately 40%. This indicates that the sample synthesized using the improved supersaturated recrystallization method of the present invention exhibited excellent stability and thermal stability at room temperature. The reasons for this can be attributed to the following: 1. Compared to Comparative Example 2, the present invention utilizes an improved supersaturated recrystallization method, allowing uniform perovskite nanomaterials to be prepared at room temperature. Furthermore, compared to Comparative Example 3, the present invention utilizes an improved supersaturated recrystallization method involving the addition of CsCl in batches, resulting in crystals with a high degree of uniformity and compositional distribution, reducing the number of lattice defects and improving stability and thermal stability at room temperature. 2. The present invention utilizes Sb2O3 rather than SbCl3, which can appropriately increase the formation of oxygen vacancies, thereby achieving the material's thermal stability. 3. The improved supersaturated recrystallization method of the present invention is carried out under relatively mild conditions, which reduces the introduction of foreign impurities and improves the stability and photoluminescence intensity of the material.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a two-dimensional antimony-based metal halide perovskite fluorescent material, comprising the following steps: (1) Dissolve Sb2O3 in concentrated hydrochloric acid and then add CsX to react; (2) Add MnX2·4H2O, CdX2 and CsX to continue the reaction. After standing, wash, separate and dry to obtain Cs4Cd x Mn 1- x Sb2X 12 ; X is one or more of Cl, Br, I, and F elements, and x is 0.1 to 0.9; The mass of CsX added in step (1) is 25% of the total mass of CsX in steps (1) and (2).

2. The method for preparing the two-dimensional antimony-based metal halide perovskite fluorescent material according to claim 1, wherein: The molar ratio of Sb2O3, MnX2·4H2O, CdX2 and CsX is 1:1-x:x:

4.

3. The method for preparing the two-dimensional antimony-based metal halide perovskite fluorescent material according to claim 1, wherein: In the step (1), the mass concentration ratio of Sb2O3 to concentrated hydrochloric acid is 290 mg:5 mL.

4. The method for preparing the two-dimensional antimony-based metal halide perovskite fluorescent material according to claim 1, wherein: In the step (1), the reaction time of adding CsX is 0.1 to 0.2 h.

5. The method for preparing the two-dimensional antimony-based metal halide perovskite fluorescent material according to claim 1, wherein: In the step (2), MnX2·4H2O, CdX2 and CsX are added and the reaction is continued for 8 to 12 hours.

6. The method for preparing the two-dimensional antimony-based metal halide perovskite fluorescent material according to claim 1, wherein: In the step (2), the standing time is 1 to 3 hours.

7. A two-dimensional antimony-based metal halide perovskite fluorescent material prepared by the method for preparing a two-dimensional antimony-based metal halide perovskite fluorescent material according to any one of claims 1 to 6.

8. The two-dimensional antimony-based metal halide perovskite fluorescent material according to claim 7, wherein: The chemical formula is Cs4CdxMn1-xSb2X12, the crystal structure is hexagonal, the space group is R-3m, and the lattice constants are a = 7.59420 Å, b = 7.59420 Å, and c = 36.8314 Å.

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