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

Abstract

The invention discloses a two-dimensional antimony-based metal halide perovskite fluorescent material and a preparation method thereof, and belongs to the technical field of metal halide perovskite fluorescent powder. The preparation method comprises the following steps: dissolving Sb2O3 in concentrated hydrochloric acid, and then adding CsX for reaction; then adding MnX2. 4H2O, CdX2 and CsX to continuously react, standing, washing, separating and drying to obtain Cs4CdxMn (1-x) Sb2X12; x is one or more of Cl, Br, I and F, and x is 0.1-0.9. According to the present invention, with the improved supersaturation recrystallization method, the photoluminescence Cs4CdxMn1-xSb2X12 material can be synthesized only at the normal temperature and the normal pressure, and the particle size of the prepared material is smaller than the particle size of the material prepared by using the solvothermal and thermal injection method, and the good crystallinity and the good light and thermal stability are provided;

Description

Technical Field

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

[0002] Halide perovskites have attracted much attention due to their high light absorption coefficient, long charge carrier diffusion length, low cost, simple synthesis methods and diverse photoelectric properties. They have great application potential in lighting sources and thermoelectric materials for optoelectronic devices. However, the synthesis of metal halide perovskites using hot injection, solvothermal method, solid phase method, chemical method, etc. has the disadvantages of large synthesized grain size and poor thermal stability. Therefore, it is necessary to find a suitable method, enrich the synthesis strategy of two-dimensional halide perovskites, improve the thermal stability of synthesized perovskites, and open up new ways to achieve efficient luminescence of halide perovskites. Summary of the invention

[0003] In view of the above-mentioned 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) Sb 2 O 3 Dissolve in concentrated hydrochloric acid, then add CsX to react;

[0006] (2) Add MnX 2 ·4H 2 O、CdX 2 Continue to react with CsX, let stand, wash, separate and dry to obtain Cs 4 Cd x Mn 1-x Sb 2 X 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 Sb 2 O 3 、MnX 2 ·4H 2 O、CdX 2 The molar ratio of X:X to CsX is 1:1-x:x:4.

[0009] As a preferred embodiment of the present invention, in step (1), Sb2 O 3 The mass concentration ratio with concentrated hydrochloric acid is 290mg:5mL.

[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), Sb 2 O 3 By reacting with part of CsX first, the synthesis time of the final two-dimensional antimony-based metal halide perovskite fluorescent material can be shortened, and the agglomeration between the two-dimensional antimony-based metal halide perovskite fluorescent material particles can be effectively avoided to form uniformly dispersed particles. 2 O 3 The molar ratio of the first reacted part of CsX is adjusted to control the amount of oxygen vacancies generated, thereby improving the stability of the two-dimensional antimony-based metal halide perovskite fluorescent material. 2 O 3 Instead of SbCl 3 To prepare perovskite fluorescent materials, it is also possible to 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 the 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), MnX is added 2 ·4H 2 O、CdX 2 The reaction time with CsX is 8 to 12 hours.

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

[0015] The present invention also claims to protect the Cs prepared by the preparation method of the two-dimensional antimony-based metal halide perovskite fluorescent material. 4 Cd x Mn 1-x Sb 2 X 12 Material; 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 Cs 4 Cd x Mn 1-x Sb 2 X 12, the crystal structure is hexagonal, the space group is R-3m, and the lattice constant is

[0017] Compared with the prior art, the present invention has the following beneficial effects: the present invention can synthesize photoluminescent Cs by using an improved supersaturated recrystallization method at room temperature and pressure. 4 Cd x Mn 1-x Sb 2 X 12 The material prepared has a finer particle size than that prepared by solvent thermal and hot injection methods, and has 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 in FIG.

[0019] Figure 2 The Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 Materials and Comparative Example 1 Cs prepared 4 Sb 2 Cl 12 SEM images and element distribution diagrams of the materials; (a) Cs 4 Sb 2 Cl 12 ; (b) is Cs 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 ; (c) Cs 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 Individual particles at 10,000 times.

[0020] Figure 3 The Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 EDS spectrum of the material.

[0021] Figure 4 The Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12Excitation spectrum of the material at 620nm.

[0022] Figure 5 The Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 Emission spectrum of the material under 351nm ultraviolet light excitation.

[0023] Figure 6 The Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 Materials and Comparative Example 1 Cs prepared 4 Sb 2 Cl 12 Comparison of photoluminescence quantum yields of materials.

[0024] Figure 7 The Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 Materials in N 2 Thermogravimetric analysis of the Cs2O3O ... 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 Cs 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 Thermogravimetric test of the sample one year ago; Cs 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 The thermogravimetric test was performed after being stored 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) 1mmolSb 2 O 3 Place in a 20 ml glass bottle, add 5 ml of concentrated hydrochloric acid and stir to dissolve evenly, then add 3 mmol CsCl and stir to react for 0.1 h to form a colloidal suspension.

[0030] (2) Add 1-x mmolMnCl to the colloidal suspension 2 ·4H 2 O, xmmolCdCl 2 (x=0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0), 1mmolCsCl, and the reaction was continued for 10h. After standing for 2h, the sample was washed with ethanol three times, the colloidal suspension was transferred to a 15ml centrifuge tube and centrifuged for 7min. The centrifuge tube was taken out and the supernatant was removed to obtain the sample, and finally dried to obtain Cs 4 Cd x Mn 1-x Sb 2 Cl 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 method for preparing a two-dimensional antimony-based metal halide perovskite fluorescent material in this embodiment and that in Embodiment 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 method for preparing a two-dimensional antimony-based metal halide perovskite fluorescent material in this embodiment and that in Embodiment 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) 1 mol% Sb 2 O 3Place 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) Add 1 mol% MnCl to the colloidal suspension 2 ·4H 2 O and 1 mol% CsCl were reacted for 10 h, and then the sample was washed with ethanol for 3 times after standing for 2 h. The colloidal suspension was transferred to a 15 ml centrifuge tube and centrifuged for 7 min. The centrifuge tube was taken out and the supernatant was removed to obtain the sample. Finally, Cs 4 Sb 2 Cl 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% Sb 2 O 3 Place in a 20ml glass bottle, add 5ml concentrated hydrochloric acid and stir to dissolve evenly, then add 0.2mol% MnCl 2 ·4H 2 O, 0.8 mol% CdCl 2 and 4 mol% CsCl were stirred evenly, and then the solvent thermal reaction was carried out at 160°C for 12 h. The sample was then washed with ethanol three times, the suspension was transferred to a 15 ml centrifuge tube and centrifuged for 7 min, the centrifuge tube was taken out and the supernatant was removed to obtain the sample, and finally dried to obtain Cs 4 Cd 0.8 Mn 0.2 Sb 2 Cl 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) 1 mol% Sb 2 O 3 Place in a 20ml glass bottle, add 5ml of concentrated hydrochloric acid and stir to dissolve evenly.

[0045] (2) Then add 0.2 mol% MnCl 2 ·4H 2 O, 0.8 mol% CdCl 2The suspension was transferred to a 15 ml centrifuge tube and centrifuged for 7 min. The supernatant was removed from the centrifuge tube to obtain the sample, and then dried to obtain Cs 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 .

[0046] like Figure 1 As shown, the Cs prepared in Example 1 4 Cd x Mn 1-x Sb 2 Cl 12 (x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0) XRD peaks of materials and Cs 4 Sb 2 Cl 12 The standard PDF card is highly matched, indicating that the method of the present invention is successfully prepared Cs 4 Cd x Mn 1-x Sb 2 Cl 12 Perovskite materials.

[0047] like Figure 2 As shown, the Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 Materials and Comparative Example 1 Cs prepared 4 Sb 2 Cl 12 All of them are nanoparticles of irregular size and shape. Compared with the materials prepared by hydrothermal method and solvothermal method, they have larger specific surface area and smaller diameter of synthesized grains ( Figure 2 c). And from EDS mapping, it can be seen that each element is evenly distributed, without obvious enrichment or aggregation.

[0048] And according to Figure 3 It can be seen that the Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 The contents of different elements in the material are 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, under monitoring at 620 nm, can be seen that the Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 The 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 A 2 → 4 T 2 , 6 A 1 → 4 T 1 transition, the latter is due to Mn 2+ Ion pair 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 important effect on the matrix Cs 4 Sb 2 Cl 12 The luminescence performance plays an important role, and the 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 this 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 improving the photoluminescence efficiency.

[0050] according to Figure 5 and 6 It can be seen that the Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 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 Cs prepared in Comparative Example 1. 4 Sb 2 Cl 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 351 nm ultraviolet light excitation, while the Cs 4 Sb 2 Cl 12 The material prepared in Comparative Example 2-3 emits orange-red light under the excitation of 351nm ultraviolet light.

[0052] according to Figure 7 It can be seen that the Cs prepared in Example 1 4 Cd 0.8 Mn 0.2 Sb 2 Cl 12 Thermogravimetric test data obtained from the material one year ago and after one year of storage at room temperature and pressure show the same trend. When the temperature rises from room temperature to about 300°C, the sample remains in its current state without decomposition. Thermal decomposition begins at 300°C-450°C, and then stabilizes after 450°C. The mass change is about 40%, indicating that the sample synthesized by the improved supersaturated recrystallization method of the present invention has good stability and thermal stability at room temperature. The reasons can be attributed to the following: 1. Compared with Comparative Example 2, the present invention adopts an improved supersaturated recrystallization method, and uniform perovskite nanomaterials can be prepared by reaction at room temperature. Moreover, compared with Comparative Example 3, the present invention uses an improved supersaturated recrystallization method in which CsCl is added in batches, so that the prepared crystals have a high degree of uniformity and composition distribution, reduce the number of lattice defects, and improve the stability and thermal stability at room temperature. 2. The present invention uses Sb 2 O 3 Instead of SbCl 3 , which can appropriately increase the formation of oxygen vacancies, thereby achieving the purpose of thermal stability of the material. 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 solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution 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 SbX 12 ; X is one or more of Cl, Br, I, and F elements, and x is 0.1 to 0.

9.

2. The method for preparing the two-dimensional antimony-based metal halide perovskite fluorescent material according to claim 1, characterized in that: 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, characterized in that: 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, characterized in that: The mass of CsX added in step (1) is 25% of the total mass of CsX in steps (1) and (2).

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

6. The method for preparing the two-dimensional antimony-based metal halide perovskite fluorescent material according to claim 1, characterized in that: In the step (2), the time for adding MnX2·4H2O, CdX2 and CsX to continue the reaction is 8 to 12 hours.

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

8. 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 7.

9. The two-dimensional antimony-based metal halide perovskite fluorescent material according to claim 8, characterized in that: The chemical formula is Cs4Cd x Mn 1-x SbX 12 , the crystal structure is hexagonal, the space group is R-3m, and the lattice constant is

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