Perovskite single crystal luminescent material and preparation method thereof

Abstract

The invention discloses a perovskite single crystal luminescent material and a preparation method thereof, and belongs to the technical field of perovskite luminescent materials. The molecular formula of the perovskite single crystal luminescent material is [ZrO (H2O) 8] 2BX6, B is one or two of Cd < 2 + >, Mn < 2 + >, Sn < 2 + >, Fe < 2 + > and Cu < 2 + >, and X is one or more of Cl <->, Br <-> and I <->. According to the perovskite single crystal luminescent material, ZrO hydrate is used for replacing traditional positive monovalent metal ions such as Cs and organic matters such as methylamine ions to serve as a site A, and divalent metal ions such as Cd < 2 + > are used for replacing traditional B-site Pb < 2 + >, so that the toxicity of the perovskite material is reduced. At the same time, the introduction of A-site Zr ions enables the luminescent characteristic of the perovskite crystal to be more multidimensional, and can simultaneously realize two dynamic processes of fluorescence and phosphorescence with different luminescent lifetime orders of magnitude, multi-wavelength emission peaks in a visible light range and multi-wavelength absorption from ultraviolet to visible light.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite luminescent materials, and in particular to a perovskite single crystal luminescent material and a preparation method thereof. Background Art

[0002] Perovskite is a three-dimensional lattice network structure composed of octahedrons connected at the same vertex, with a general structural formula of ABX3, where A = Cs + , CH3NH3 + (MA + ), CH3CH2NH2 + (EA + ) etc.; B=Pb 2+ ,In 3+ , Sb 3+ etc., X=Cl - ,Br - , I - With the rapid development of optoelectronic semiconductor devices in recent years, perovskite materials have attracted much attention due to their simple preparation methods, low raw material costs and unique optical properties. However, most of the current perovskite materials are Cs + Metal ions such as methylamine ions or organic ammonium ions such as Pb 2+ Although the introduction of ions as B sites, heavy metals and organic matter can provide effective charge transfer channels for perovskite materials and achieve higher photoluminescence quantum yield (PLQY), their introduction will lead to toxicity problems of perovskite materials. Summary of the invention

[0003] The purpose of the present invention is to provide a perovskite single crystal luminescent material and a preparation method thereof to solve the problems existing in the above-mentioned prior art.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] One of the technical solutions of the present invention is: a perovskite single crystal luminescent material, wherein the molecular formula of the perovskite single crystal luminescent material is [ZrO(H2O)8]2BX6, wherein B is Cd 2+ , Mn 2+ Sn 2+ , Fe 2+ and Cu 2+ One or two of the following, X is Cl - Br - and I - One or more of .

[0006] The perovskite single crystal luminescent material of the present invention uses ZrO hydrate to replace the conventional monovalent metal ions such as Cs and methylamine ions (MA +) and other organic substances as the A site of the perovskite material, using Cd 2+ , Mn 2+ Sn 2+ , Fe 2+ and Cu 2+ Divalent metal ions replace the traditional B-site Pb 2+ , greatly reducing the toxicity of the perovskite material. At the same time, by introducing Zr ions at the A position, the perovskite crystal has multiple wavelength emission peaks under ultraviolet excitation at 254nm. Compared with the single luminescence characteristics of traditional perovskite materials, the luminescence characteristics of the perovskite single crystal luminescent material of the present invention are more multi-dimensional, and can simultaneously realize the dynamic process of two different luminescence lifetimes of fluorescence and phosphorescence, multi-wavelength emission peaks in the visible light range, and multi-wavelength absorption from ultraviolet to visible light. Therefore, the perovskite single crystal luminescent material of the present invention can be prepared into anti-counterfeiting inks, anti-counterfeiting films and other products, and has broad potential application value in the field of luminescent anti-counterfeiting.

[0007] Furthermore, the subscript in [ZrO(H2O)8]2BX6 represents the molar ratio of the A-site ions, B-site ions, and X-site ions in the perovskite material, i.e., the A-site ions ([ZrO(H2O)8] 2+ ), B-site ions (Cd 2+ , Mn 2+ Sn 2+ , Fe 2+ and Cu 2+ One or two of them) and X-site ions (Cl-, Br - and I-) in a molar ratio of 2:1:6. When the B-site ion is Cd 2+ , Mn 2+ Sn 2 + , Fe 2+ and Cu 2+ When there are two of them, the two B-site ions can be in any molar ratio.

[0008] Further preferably, the molecular formula of the perovskite single crystal luminescent material is [ZrO(H2O)8]2MnCl6, [ZrO(H2O)8]2CdCl6 or [ZrO(H2O)8]2Cd 0.5 Mn 0.5 The perovskite single crystal luminescent material of the present invention includes any one of the molecular formulas [ZrO(H2O)8]2BX6, wherein [ZrO(H2O)8]2MnCl6, [ZrO(H2O)8]2CdCl6 and [ZrO(H2O)8]2Cd 0.5 Mn 0.5 The photoluminescence quantum yield (PLQY) of Cl6 is relatively high.

[0009] The second technical solution of the present invention: The preparation method of the above-mentioned perovskite single crystal luminescent material comprises the following steps: dissolving a Zr source and a B source in an acid containing X, respectively, to obtain a Zr source solution and a B source solution; mixing the Zr source solution and the B source solution to obtain a perovskite precursor solution; and allowing the perovskite precursor solution to stand and crystallize to obtain the perovskite single crystal luminescent material.

[0010] Furthermore, the Zr source is a Zr (zirconium) salt; the B source is one or two of a Cd salt, a Mn salt, a Sn salt, a Fe salt and a Cu salt.

[0011] Furthermore, the acid containing X is one or more of hydrochloric acid, hydrobromic acid and hydrofluoric acid.

[0012] Furthermore, the concentration of the hydrochloric acid is 36wt%.

[0013] Further, the B source is two of Cd salt, Mn salt, Sn salt, Fe salt and Cu salt, and the Zr source and the B source are respectively dissolved in an acid containing X to obtain a Zr source solution and a B source solution, comprising: dissolving the Zr source in an acid containing X to obtain a Zr source solution, and dissolving two B sources in an acid containing X to obtain two B source solutions; and mixing the Zr source solution and the B source solution to obtain a perovskite precursor solution comprises: mixing the Zr source solution and two B source solutions to obtain the perovskite precursor solution.

[0014] Furthermore, the molar ratio of the Zr source to the B source is 0.2:0.1-1.0, preferably 0.2:0.3-0.5.

[0015] Further preferably, when the B source includes a Cd salt, the molar ratio of the Zr salt to the Cd salt is 0.2:0.3; when the B source includes a Mn salt, the molar ratio of the Zr salt to the Mn salt is 0.2:0.5; when the B source includes a Sn salt, the molar ratio of the Zr salt to the Sn salt is 0.2:0.4; when the B source includes a Fe salt, the molar ratio of the Zr salt to the Fe salt is 0.2:0.3.

[0016] Furthermore, the concentration of the Zr source in the Zr source solution is 0.2 to 1.0 mol / L; the concentration of the B source in the B source solution is 0.05 to 1.0 mol / L, preferably 0.25 to 0.625 mol / L.

[0017] The concentration of the Zr source solution and the B source solution is controlled to ensure that the solute concentration in the solution is moderate, so that the solute does not precipitate rapidly due to oversaturation or does not precipitate due to too low a concentration.

[0018] Furthermore, the static crystallization is carried out at a temperature of 25±0.5°C (the temperature of the entire static crystallization process is maintained within the range of 25±0.5°C), and the static crystallization time is 2 to 6 days.

[0019] Furthermore, the disturbance of the surrounding airflow needs to be reduced during the static crystallization process to avoid affecting the crystal growth process, resulting in poor quality of the obtained perovskite single crystal. To achieve this goal, the perovskite precursor solution can be placed in a closed space for static crystallization.

[0020] Further, the step of dissolving the Zr source and the B source in an acid containing X to obtain a Zr source solution and a B source solution comprises: adding the Zr source and the B source to the acid containing X, respectively, and heating at a temperature of 80° C. until the Zr source and the B source are completely dissolved to obtain a Zr source solution and a B source solution; and the step of mixing the Zr source solution and the B source solution to obtain a perovskite precursor solution comprises: cooling the Zr source solution and the B source solution to room temperature (25° C.), mixing them, and then filtering them to obtain the perovskite precursor solution.

[0021] The purpose of filtering after mixing the Zr source solution and the B source solution cooled to room temperature is to reduce the number of crystal nuclei or some undissolved impurities in the perovskite precursor solution, thereby reducing the seed crystals in the precursor solution, which is beneficial to obtain larger target crystals and improve the crystal quality.

[0022] The third technical solution of the present invention: Application of the above-mentioned perovskite single crystal luminescent material in the field of luminescent anti-counterfeiting.

[0023] The present invention discloses the following technical effects:

[0024] (1) The present invention utilizes ZrO hydrate to replace the traditional highly toxic heavy metal Cs and other positive monovalent metal ions and methylamine ions (MA + ) and other organic substances as the A site of the perovskite material, which reduces the toxicity of the perovskite material and introduces the characteristics of new metal ions. 2+ , Mn 2+ Sn 2+ , Fe 2+ , Cu 2+ The divalent metal ions replaced the traditional biologically toxic B-site Pb 2+ , synthesized non-toxic non-lead perovskite single crystal light-emitting material, solving the problem of high toxicity of traditional perovskite materials.

[0025] (2) The present invention introduces zirconium ions at the A position, so that the perovskite single crystal luminescent material has multiple wavelength emission peaks under ultraviolet excitation of 254nm. Compared with the single luminescent characteristics of traditional perovskites, the luminescent characteristics of the perovskite single crystal luminescent material of the present invention are more multi-dimensional, and can simultaneously achieve transient lifetimes of different orders of magnitude, multi-wavelength emission in the visible light range, and multi-wavelength absorption from ultraviolet to visible light.

[0026] (3) The perovskite single crystal light-emitting material of the present invention only needs to be left to stand at room temperature during the synthesis process. Compared with the traditional cooling crystallization or anti-solvent method of oxygen-based or halogen-based perovskite growth method, the single crystal growth method of the present invention is simpler and safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 The comparison results of the theoretical X-ray diffraction pattern of the [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in Example 1 and the powder X-ray diffraction pattern obtained by actual measurement;

[0029] Figure 2 The photoluminescence spectrum of the [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in Example 1 under the test conditions of 254nm ultraviolet light excitation;

[0030] Figure 3 The excitation spectrum of the [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in Example 1 under the test conditions of 620nm emission;

[0031] Figure 4 The transient lifetime test result of the 445nm emission peak of the [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in Example 1;

[0032] Figure 5 The transient lifetime test result of the 620nm emission peak of the [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in Example 1;

[0033] Figure 6 The comparison results of the theoretical X-ray diffraction pattern of the [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in Example 2 and the powder X-ray diffraction pattern obtained by actual measurement;

[0034] Figure 7The photoluminescence spectrum of the [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in Example 2 under the test conditions of 254nm ultraviolet light excitation;

[0035] Figure 8 The excitation spectrum of the [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in Example 2 under the test conditions of 420nm emission;

[0036] Fig. 9 The transient lifetime test result of the 445nm emission peak of the [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in Example 2;

[0037] Fig.10 The transient lifetime test result of the 620nm emission peak of the [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in Example 2;

[0038] Fig.11 [ZrO(H2O)8]2Cd prepared in Example 3 0.5 Mn 0.5 Comparison results of the theoretical X-ray diffraction pattern of Cl6 perovskite single crystal and the powder X-ray diffraction pattern obtained by actual measurement.

[0039] Fig.12 [ZrO(H2O)8]2Cd prepared in Example 3 0.5 Mn 0.5 Photoluminescence spectrum of Cl6 perovskite single crystal under test conditions of 254nm UV excitation;

[0040] Fig.13 [ZrO(H2O)8]2Cd prepared in Example 3 0.5 Mn 0.5 Excitation spectrum of Cl6 perovskite single crystal under test conditions of 620nm emission;

[0041] Fig.14 [ZrO(H2O)8]2Cd prepared in Example 3 0.5 Mn 0.5 Transient lifetime test results of the 445nm emission peak of Cl6 perovskite single crystal;

[0042] Fig.15 [ZrO(H2O)8]2Cd prepared in Example 3 0.5 Mn 0.5 Transient lifetime test results of the 620nm emission peak of Cl6 perovskite single crystal. DETAILED DESCRIPTION

[0043] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0044] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0045] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0046] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0047] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0048] As a first aspect of the present invention, the present invention provides a perovskite single crystal luminescent material, wherein the molecular formula of the perovskite single crystal luminescent material is [ZrO(H2O)8]2BX6, wherein B is Cd 2+ , Mn 2+ Sn 2+ , Fe 2+ and Cu 2+ One or two of the following, X is Cl-, Br - and I - One or more of .

[0049] As a preferred embodiment of the present invention, the molecular formula of the perovskite single crystal luminescent material is [ZrO(H2O)8]2MnCl6, [ZrO(H2O)8]2CdCl6 or [ZrO(H2O)8]2Cd 0.5Mn 0.5 Cl6.

[0050] As a second aspect of the present invention, the present invention provides a method for preparing the above-mentioned perovskite single crystal luminescent material, comprising the following steps: dissolving a Zr source and a B source in an acid containing X, respectively, to obtain a Zr source solution and a B source solution; mixing the Zr source solution and the B source solution to obtain a perovskite precursor solution; allowing the perovskite precursor solution to stand and crystallize to obtain the perovskite single crystal luminescent material.

[0051] As a preferred embodiment of the present invention, the preparation method more specifically comprises the following steps:

[0052] (1) adding a Zr source (Zr salt) and a B source (one or two of Cd salt, Mn salt, Sn salt, Fe salt and Cu salt) to an acid containing X respectively, placing the mixture on a heating table at 80° C. and heating the mixture until the solute is completely dissolved to obtain a clear and transparent liquid, i.e., obtaining a Zr source solution and a B source solution (one or two B source solutions);

[0053] (2) cooling the clear and transparent zirconium source solution and B source solution obtained in step (1) to room temperature (25° C.), and taking care not to shake the liquid during the cooling process to prevent the solute from being disturbed and rapidly precipitating; mixing the cooled Zr source solution and B source solution (one or two B source solutions), and filtering the mixed solution to reduce the number of crystal nuclei in the perovskite precursor solution, thereby obtaining a transparent and clear perovskite precursor solution;

[0054] (3) The perovskite precursor solution is allowed to stand at room temperature (25±0.5°C, and the temperature of the entire static crystallization process is maintained within the range of 25±0.5°C) for 2 to 6 days for crystallization (single crystal growth), and finally a transparent perovskite single crystal light-emitting material is obtained; during the static process, the perovskite precursor solution is placed in a closed space to minimize temperature fluctuations and airflow disturbances in the growth environment.

[0055] As a preferred embodiment of the present invention, the acid containing X is one or more of hydrochloric acid, hydrobromic acid and hydrofluoric acid.

[0056] As a preferred embodiment of the present invention, the concentration of the hydrochloric acid is 36 wt %.

[0057] As an embodiment of the present invention, the molar ratio of the Zr source to the B source is 0.2:0.1 to 1.0, preferably 0.2:0.3 to 0.5.

[0058] As a preferred embodiment of the present invention, when the B source includes a Cd salt, the molar ratio of the Zr salt to the Cd salt is 0.2:0.3; when the B source includes a Mn salt, the molar ratio of the Zr salt to the Mn salt is 0.2:0.5; when the B source includes a Sn salt, the molar ratio of the Zr salt to the Sn salt is 0.2:0.4; when the B source includes a Fe salt, the molar ratio of the Zr salt to the Fe salt is 0.2:0.3.

[0059] As an embodiment of the present invention, the concentration of the Zr source in the Zr source solution is 0.2 to 1.0 mol / L; the concentration of the B source in the B source solution is 0.05 to 1.0 mol / L, preferably 0.25 to 0.625 mol / L.

[0060] As a third aspect of the present invention, the present invention provides an application of the above-mentioned perovskite single crystal luminescent material in the field of luminescent anti-counterfeiting.

[0061] The perovskite single crystal light-emitting material and the preparation method thereof of the present invention are further described below in conjunction with specific embodiments.

[0062] All raw materials used in the following examples and comparative examples are common commercially available products.

[0063] Example 1 Preparation of [ZrO(H2O)8]2MnCl6 Perovskite Single Crystal Luminescent Material

[0064] (1) 0.2 mmol (0.0466 g) of zirconium chloride powder and 0.5 mmol (0.0989 g) of manganese chloride tetrahydrate powder were added to 0.8 mL of 36 wt% concentrated hydrochloric acid solution, respectively, and placed on a heating table at 80° C. for 10 min to observe whether the solute is fully dissolved. If not completely dissolved, it can be properly shaken to promote its dissolution or the heating time can be extended to promote its dissolution until the solute is completely dissolved to obtain a clear and transparent liquid, that is, a zirconium (Zr) source solution and a manganese (Mn) source solution are obtained.

[0065] (2) Cool the clear and transparent zirconium source solution and manganese source solution obtained in step (1) to room temperature (25° C.), and be careful not to shake the liquid during the cooling process to prevent the solute from being disturbed and quickly precipitating. Mix the cooled zirconium source solution and manganese source solution, and filter the mixed solution to reduce the number of crystal nuclei in the perovskite precursor solution to obtain a transparent and clear perovskite precursor solution.

[0066] (3) The perovskite precursor solution was allowed to stand at room temperature (25±0.5°C, the temperature was kept within the range of 25±0.5°C during the entire standing process) for 4 days for crystallization (single crystal growth), and finally a transparent [ZrO(H2O)8]2MnCl6 perovskite single crystal was obtained. During the standing process, the perovskite precursor solution was placed in a closed space to minimize the temperature fluctuation and airflow disturbance in the growth environment.

[0067] The [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in this embodiment is close to a cube in shape and, after testing, has a size of about 1 cm×1 cm×1 cm.

[0068] Figure 1 The comparison results of the theoretical X-ray diffraction pattern of the [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in Example 1 and the powder X-ray diffraction pattern obtained by actual measurement prove the successful preparation of the [ZrO(H2O)8]2MnCl6 perovskite single crystal.

[0069] Figure 2 The photoluminescence spectrum of the [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in this example under the test conditions of 254nm ultraviolet light excitation is shown in FIG. Figure 2 It can be seen that the emission wavelength of the crystal is multi-dimensional, among which the main emission peak at 620nm appears as orange-red light emission.

[0070] Figure 3 The excitation spectrum of the [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in this embodiment under the test conditions of 620nm emission is shown in FIG. Figure 3 It can be seen that the excitation wavelength of the crystal is multi-dimensional, and there are multiple excitation lights in the range of 300nm ultraviolet light to 530nm visible light that can make the crystal emit orange-red light.

[0071] The transient lifetime of the [ZrO(H2O)8]2MnCl6 perovskite single crystal prepared in this embodiment at different emission wavelengths (the test conditions are 375nm excitation and 254nm excitation, both in the ultraviolet region), and the test results are fitted using the ExpDec2 model, as shown in FIG. Figure 4 and Figure 5 As shown in the figure, the fitting results show that the short lifetime of the 445nm emission peak is 0.78ns, the long lifetime is 6.60ns, and the calculated average lifetime is 1.64ns, which is the conventional fluorescence lifetime (such as Figure 4 As shown); the short lifetime of the 620nm emission peak is 0.62ms, the long lifetime is 3.28ms, and the calculated average lifetime is 2.71ms, which is the phosphorescence lifetime (as shown Figure 5 In addition, the PLQY of the crystal measured at 254 nm was 4.8%.

[0072] Example 2 Preparation of [ZrO(H2O)8]2CdCl6 Perovskite Single Crystal Luminescent Material

[0073] (1) 0.2 mmol (0.0466 g) of zirconium chloride powder and 0.3 mmol (0.055 g) of cadmium chloride powder were added to 0.8 mL of 36 wt% concentrated hydrochloric acid solution, respectively, and placed on a heating table at 80°C for 10 min to observe whether the solute is fully dissolved. If not completely dissolved, it can be properly shaken to promote its dissolution or the heating time can be extended to promote its dissolution until the solute is completely dissolved to obtain a clear and transparent liquid, that is, a zirconium (Zr) source solution and a cadmium (Cd) source solution are obtained.

[0074] (2) Cool the clear and transparent zirconium source solution and cadmium source solution obtained in step (1) to room temperature (25° C.), and be careful not to shake the liquid during the cooling process to prevent the solute from being disturbed and quickly precipitating. Mix the cooled zirconium source solution and cadmium source solution, and filter the mixed solution to reduce the number of crystal nuclei in the perovskite precursor solution to obtain a transparent and clear perovskite precursor solution.

[0075] (3) The perovskite precursor solution was allowed to stand at room temperature (25±0.5°C, the temperature was kept within the range of 25±0.5°C during the entire standing process) for 4 days for crystallization (single crystal growth), and finally a transparent [ZrO(H2O)8]2CdCl6 perovskite single crystal was obtained. During the standing process, the perovskite precursor solution was placed in a closed space to minimize the temperature fluctuation and airflow disturbance in the growth environment.

[0076] The [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in this embodiment is close to a cube in shape, and after testing, the size is about 1cm×1cm×1cm.

[0077] Figure 6 The comparison results of the theoretical X-ray diffraction pattern of the [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in Example 2 and the powder X-ray diffraction pattern obtained by actual measurement prove the successful preparation of the [ZrO(H2O)8]2CdCl6 perovskite single crystal.

[0078] Figure 7 The photoluminescence spectrum of the [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in this example under the test conditions of 254nm ultraviolet light excitation is shown in FIG. Figure 7 It can be seen that the emission wavelength of the crystal is multi-dimensional, among which the main emission peak at 420nm appears as violet light emission.

[0079] Figure 8The excitation spectrum of the [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in this example under the test conditions of 420nm emission is shown in FIG. Figure 8 It can be seen that the excitation peaks of the crystal at 250nm and 345nm are both located in the ultraviolet light region.

[0080] The transient lifetime of the [ZrO(H2O)8]2CdCl6 perovskite single crystal prepared in this embodiment at different emission wavelengths (the test conditions are 375nm excitation and 254nm excitation, both in the ultraviolet region), and the test results are fitted using the ExpDec2 model, as shown in FIG. Fig. 9 and Fig.10 As shown in the fitting results, the short lifetime of the 445nm emission peak is 0.80008ns, the long lifetime is 5.08392ns, and the calculated average lifetime is 1.30ns, which is the conventional fluorescence lifetime (such as Fig. 9 As shown); the short lifetime of the 620nm emission peak is 0.39000ms, the long lifetime is 7.42200ms, and the calculated average lifetime is 2.31ms, which is the phosphorescence lifetime (as shown Fig.10 In addition, the PLQY of the crystal at 254 nm was tested to be 3.1%.

[0081] Example 3 [ZrO(H2O)8]2Cd 0.5 Mn 0.5 Preparation of Cl6 perovskite single crystal luminescent material

[0082] (1) 0.2 mmol (0.0466 g) of zirconium chloride powder, 0.3 mmol (0.055 g) of cadmium chloride powder and 0.5 mmol (0.0989 g) of manganese chloride tetrahydrate powder were added to 0.8 mL of 36 wt% concentrated hydrochloric acid solution, respectively, and heated on a heating table at 80° C. for 10 min to observe whether the solute is fully dissolved. If not completely dissolved, it can be properly shaken to promote its dissolution or the heating time can be extended to promote its dissolution until the solute is completely dissolved to obtain a clear and transparent liquid, that is, a zirconium (Zr) source solution, a cadmium (Cd) source solution and a manganese (Mn) source solution are obtained.

[0083] (2) Cool the clear and transparent zirconium source solution, cadmium source solution and manganese source solution obtained in step (1) to room temperature (25° C.), and be careful not to shake the liquid during the cooling process to prevent the solute from being disturbed and quickly precipitating. Mix the cooled zirconium source solution, cadmium source solution and manganese source solution, and filter the mixed solution to reduce the number of crystal nuclei in the perovskite precursor solution to obtain a transparent and clear perovskite precursor solution.

[0084] (3) The perovskite precursor solution was allowed to stand at room temperature (25±0.5°C, the temperature was kept within the range of 25±0.5°C during the entire standing process) for 4 days for crystallization (single crystal growth), and finally a transparent [ZrO(H2O)8]2Cd 0.5 Mn 0.5 Cl6 perovskite single crystal. During the static process, the perovskite precursor solution was placed in a closed space to minimize the temperature fluctuation and airflow disturbance in the growth environment.

[0085] [ZrO(H2O)8]2Cd prepared in this example 0.5 Mn 0.5 The shape of the Cl6 perovskite single crystal is close to that of a cube, and after testing, its size is approximately 1cm×1cm×1cm.

[0086] Fig.11 [ZrO(H2O)8]2Cd prepared in Example 3 0.5 Mn 0.5 The comparison between the theoretical X-ray diffraction pattern of Cl6 perovskite single crystal and the actual measured powder X-ray diffraction pattern proves that [ZrO(H2O)8]2Cd 0.5 Mn 0.5 Successful preparation of Cl6 perovskite single crystals.

[0087] Fig.12 [ZrO(H2O)8]2Cd prepared in this example 0.5 Mn 0.5 Photoluminescence spectrum of Cl6 perovskite single crystal under 254nm ultraviolet light excitation test conditions, by Fig.12 It can be seen that the emission wavelength of the crystal is multi-dimensional, among which the main emission peak at 620nm appears as orange-red light emission.

[0088] Fig.13 [ZrO(H2O)8]2Cd prepared in this example 0.5 Mn 0.5 The excitation spectrum of Cl6 perovskite single crystal under the test conditions of 620nm emission, Fig.13 It can be seen that the excitation wavelength of the crystal is multi-dimensional, and there are multiple excitation lights in the range of 300nm ultraviolet light to 530nm visible light that can make the crystal emit orange-red light.

[0089] Test the [ZrO(H2O)8]2Cd prepared in this example 0.5 Mn 0.5 The transient lifetime of Cl6 perovskite single crystal at different emission wavelengths (the test conditions are 375nm excitation and 254nm excitation, both in the ultraviolet region), and the test results are fitted using the ExpDec2 model, such as Fig.14 and Fig.15As shown in the fitting results, the short lifetime of the 445nm emission peak is 0.75991ns, the long lifetime is 5.23108ns, and the calculated average lifetime is 1.64ns, which is the conventional fluorescence lifetime (such as Fig.14 The short lifetime of the 620nm emission peak is 0.59033ms, the long lifetime is 3.65078ms, and the calculated average lifetime is 3.33ms, which is the phosphorescence lifetime (as shown in Fig.15 In addition, the PLQY of the crystal at 254 nm was tested to be 4.9%.

[0090] The detailed crystal information obtained by analyzing the X-ray diffraction patterns of the perovskite single crystal luminescent materials prepared in Examples 1 to 3 is shown in Table 1:

[0091] Table 1

[0092]

[0093]

[0094] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A perovskite single crystal luminescent material, characterized in that: The molecular formula of the perovskite single crystal luminescent material is [ZrO(H2O)8]2BX6, wherein B is Cd 2+ , Mn 2+ Sn 2+ , Fe 2+ and Cu 2+ One or two of the following, X is Cl - Br - and I - One or more of .

2. The perovskite single crystal light-emitting material according to claim 1, characterized in that: The molecular formula of the perovskite single crystal luminescent material is [ZrO(H2O)8]2MnCl6, [ZrO(H2O)8]2CdCl6 or [ZrO(H2O)8]2Cd 0.5 Mn 0.5 Cl6.

3. The method for preparing a perovskite single crystal luminescent material according to claim 1, characterized in that: The following steps are involved: Dissolving a Zr source and a B source in an acid containing X, respectively, to obtain a Zr source solution and a B source solution; Mixing the Zr source solution and the B source solution to obtain a perovskite precursor solution; The perovskite precursor solution is allowed to stand for crystallization to obtain the perovskite single crystal light-emitting material.

4. The preparation method according to claim 3, characterized in that: The Zr source is a Zr salt; the B source is one or two of a Cd salt, a Mn salt, a Sn salt, a Fe salt and a Cu salt.

5. The preparation method according to claim 4, characterized in that: The B source is two of Cd salt, Mn salt, Sn salt, Fe salt and Cu salt. The steps of dissolving the Zr source and the B source in an acid containing X to obtain a Zr source solution and a B source solution respectively include: dissolving the Zr source in an acid containing X to obtain a Zr source solution, and dissolving two B sources in an acid containing X to obtain two B source solutions respectively. The steps of mixing the Zr source solution and the B source solution to obtain a perovskite precursor solution include: mixing the Zr source solution and two B source solutions to obtain the perovskite precursor solution.

6. The preparation method according to claim 3, characterized in that: The molar ratio of the Zr source to the B source is 0.2:0.1-1.

0.

7. The preparation method according to claim 3, characterized in that: The concentration of the Zr source in the Zr source solution is 0.2-1.0 mol / L; the concentration of the B source in the B source solution is 0.05-1.0 mol / L.

8. The preparation method according to claim 3, characterized in that: The static crystallization is carried out at a temperature of 25±0.5° C., and the time for the static crystallization is 2 to 6 days.

9. The preparation method according to claim 3, characterized in that: The step of dissolving the Zr source and the B source in an acid containing X to obtain a Zr source solution and a B source solution comprises: adding the Zr source and the B source to the acid containing X, heating at a temperature of 80° C. until the Zr source and the B source are completely dissolved, to obtain a Zr source solution and a B source solution; and the step of mixing the Zr source solution and the B source solution to obtain a perovskite precursor solution comprises: cooling the Zr source solution and the B source solution to room temperature, mixing them, and then filtering them to obtain the perovskite precursor solution.

10. Use of the perovskite single crystal luminescent material according to any one of claims 1 to 2 in the field of luminescent anti-counterfeiting.

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