An AgBr-doped CsPbBr3 quantum dot glass crystal and its preparation and application

Abstract

The application discloses AgBr-doped CsPbBr3 quantum dot microcrystalline glass as well as a preparation method and application thereof. B2O3, ZnO, SiO2, MgO, Al2O3, CaO, AgBr, Cs2CO3, PbBr2 and NaBr are used as raw materials, and the AgBr-doped CsPbBr3 quantum dot microcrystalline glass is obtained through the following steps: mixing and melting, water quenching, drying, grinding and sieving, heat treatment and crystallization, and cooling. The application also provides application of the AgBr-doped CsPbBr3 quantum dot glass in preparation of a liquid crystal display backlight plate. The AgBr-doped CsPbBr3 quantum dot microcrystalline glass prepared by the application has excellent quantum efficiency, higher stability and a wider color gamut, and the prepared liquid crystal display backlight plate still has good stability under aging conditions of high humidity, high temperature and high blue light.

Description

Technical Field

[0001] This invention relates to an AgBr-doped CsPbBr3 quantum dot microcrystalline glass, its preparation and application, and belongs to the field of luminescent glass. Background Technology

[0002] With the development of high-quality synthesis processes, all-inorganic CsPbX3 (X = I, Br, Cl) perovskite nanocrystals have attracted widespread research attention due to their excellent photoelectric properties. By controlling the size and composition of CsPbX3, high color purity, high photoluminescence quantum yield (PLQY), and broadly tunable colors across the entire visible spectrum can be achieved. These remarkable properties demonstrate the great potential of CsPbX3 in backlight displays, LEDs, lasers, and photodetectors. However, their extremely poor stability when exposed to water, heat, light, and oxygen severely limits their practical applications.

[0003] To improve the moisture stability, thermal stability, and photostability of CsPbX3 quantum dots, methods such as surface modification, encapsulation protection, synthetic improvement, structural modification, and the addition of stabilizers can be employed. These methods can be used individually or in combination to enhance the stability and photoelectric properties of perovskite quantum dots. These improvement methods are of great significance for the practical applications of perovskite quantum dots. Among these strategies, embedding CsPbX3 in glass has proven to have particularly promising practical applications. Currently, CsPbX3 has been successfully encapsulated in borosilicate, germanium borate, phosphobic acid borate, phosphosilicate, and tellurium borate glass matrices. These glass matrices tightly surround CsPbX3, preventing its exposure to water and oxygen through a dense network structure. Furthermore, due to the scarcity of free electrons in the glass structure, its poor thermal conductivity can partially reduce the impact of temperature on perovskite quantum dots. However, unfortunately, the characteristic of CsPbX3 quantum dots being easily decomposed by light when encapsulated in inorganic glass matrices remains unresolved. To improve its photostability, doping with a modifier in a CsPbX3 nanocrystalline glass matrix is ​​one of the effective methods to enhance its stability. Summary of the Invention

[0004] To address the problem of poor photostability of CsPbBr3 quantum dot glass, this invention provides a method for preparing AgBr-doped CsPbBr3 quantum dot glass, achieving high quantum efficiency and high stability.

[0005] The technical solution adopted in this invention is as follows:

[0006] In a first aspect, the present invention provides an AgBr-doped CsPbBr3 quantum dot microcrystalline glass, which is obtained by taking raw materials according to a glass formulation, mixing and melting, water quenching, drying, grinding and sieving, heat treatment for crystallization, and cooling; the glass formulation consists of the following raw material components, wherein the component content is expressed in parts by weight:

[0007]

[0008] Preferably, the glass formulation consists of the following raw material components:

[0009]

[0010]

[0011] As a further preferred embodiment, the glass formulation comprises the following raw material components:

[0012]

[0013] As a further preferred embodiment, the glass formulation comprises the following raw material components:

[0014]

[0015]

[0016] The most preferred glass formulation of this invention comprises the following raw material components:

[0017]

[0018] In a second aspect, the present invention provides a method for preparing AgBr-doped CsPbBr3 quantum dot microcrystalline glass as described in the first aspect, comprising the following steps:

[0019] (1) Weigh the raw material components according to the glass formula, mix the raw material components and grind them evenly, and then place them in a crucible;

[0020] (2) Place the crucible obtained in step (1) into a lifting furnace, raise the temperature to 1100-1400℃, keep it at high temperature for 5-30 minutes, and then pour the glass melt into water for water quenching to obtain glass slag.

[0021] (3) The glass slag obtained in step (2) is placed in an oven for drying at a temperature of 40-100℃ for 1-15 hours to obtain the precursor glass.

[0022] (4) Grind and sieve the precursor glass obtained in step (3) to obtain precursor glass powder; perform machine ball milling and sieve through 200-1000 mesh to obtain precursor glass powder with different particle sizes.

[0023] (5) The precursor glass powder obtained in step (4) is placed in a crystallization furnace, heated to 440-540℃ and held for 100-1000 min to allow CsPbBr3 to precipitate and grow in the glass, and then cooled with the furnace to obtain AgBr-doped CsPbBr3 quantum dot glass material.

[0024] Preferably, in step (1) of the present invention, the crucible used is a corundum crucible.

[0025] Preferably, in step (2) of the present invention, the melting temperature is 1200°C.

[0026] Preferably, in step (2) of the present invention, the melting time is 10 minutes.

[0027] Preferably, in step (5) of the present invention, the temperature is heated to 500°C and kept at that temperature for 300 minutes.

[0028] Thirdly, the present invention provides the application of the AgBr-doped CsPbBr3 quantum dot glass described in the first aspect in the preparation of liquid crystal display backlight panels.

[0029] The specific application involves mixing AgBr-doped CsPbBr3 quantum dot glass material with PS and then melting and extruding it to obtain a backlight panel.

[0030] Preferably, the mass ratio of the AgBr-doped CsPbBr3 quantum dot glass material to PS is 4-7:1000.

[0031] Compared with the prior art, the advantages of the present invention are:

[0032] (1) The B2O3-SiO2-ZnO-MgO-Al2O3-CaO-based glass system used in this invention can effectively prevent CsPbBr3 from being destroyed in air and obtain CsPbBr3 quantum dots.

[0033] (2) AgBr has the property of being easily decomposed in light. In this invention, it is incorporated into a glass matrix, which decomposes into Br upon irradiation. - This fills the Br vacancies created during CsPbBr3 illumination. Furthermore, Ag... + During the cooling process of the glass melt, some of the particles are reduced to silver nanoparticles. These particles can act as nucleating agents to improve the precrystallization ability of CsPbBr3 and can also generate a plasmonic resonance effect in the glass matrix, resulting in excellent quantum efficiency and higher stability, thus enabling control over the optical properties of CsPbBr3 quantum dot glass.

[0034] (3) The PS liquid crystal display backlight of the present invention still has good stability under aging conditions of high humidity, high temperature and high blue light. After doping with 1.0 AgBr, its stability is significantly improved compared with that without AgBr.

[0035] (4) The AgBr-doped CsPbBr3 quantum dot glass material of the present invention has a wider color gamut in display.

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0038] Figure 1 The image shows a sample of the precursor glass prepared according to an embodiment of the present invention. As can be seen from the photographs under sunlight and ultraviolet light, the five samples become darker under normal light and green light becomes more obvious under ultraviolet light irradiation as the AgBr doping concentration increases, indicating that AgBr can promote the pre-crystallization ability of CsPbBr3.

[0039] Figure 2 This is a sample image of the CsPbBr3 quantum dot microcrystalline glass material prepared according to an embodiment of the present invention.

[0040] Figure 3 The image shows the XRD pattern of the CsPbBr3 quantum dot microcrystalline glass material prepared according to an embodiment of the present invention. The image shows that the position of the 110 crystal plane peak changes with the increase of AgBr concentration.

[0041] Figure 4 The image shows the PL fluorescence and absorption of the CsPbBr3 quantum dot microcrystalline glass material prepared in an embodiment of the present invention.

[0042] Figure 5 The image shows a sample of backlight panel A prepared according to an embodiment of the present invention. The left image is a normal light image, and the right image is a violet light image.

[0043] Figure 6 Stability diagrams of backlight panels A and B prepared according to embodiments of the present invention.

[0044] Figure 7 Example 3 of this invention uses commercial phosphor K2SiF6:Mn 4+ The color gamut map excited by the combined blue light chip. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0046] Examples 1-5

[0047] (1) Weigh the raw material components according to the glass formula shown in Table 1, mix each raw material component and grind it evenly, and then place it in a corundum crucible.

[0048] (2) Place the corundum crucible in a muffle furnace and raise the temperature from room temperature to 1200°C over 120 minutes, then hold for 10 minutes. Next, pour the molten glass into water for quenching to obtain glass slag.

[0049] (3) Place the glass shards in a 60℃ oven for 500 minutes to dry, and wait for the glass precursor to dry completely to obtain the precursor glass. Sample images of the precursor glass under sunlight and ultraviolet light are shown below. Figure 1 As shown;

[0050] (4) The precursor glass was then mechanically ball-milled and passed through a 350-mesh sieve to obtain precursor glass powder.

[0051] (5) The precursor glass powder was placed in an annealing furnace, heated to 500℃ and held for 300 min to allow CsPbBr3 to precipitate and grow in the glass. The mixture was then cooled in the furnace to obtain CsPbBr3 quantum dot glass material. Sample images under sunlight and ultraviolet light are shown below. Figure 2 As shown.

[0052] Table 1

[0053]

[0054]

[0055] The prepared quantum dot glass-ceramics were subjected to structural analysis and related tests such as photoelectric properties, etc. Figure 3 As shown, the XRD pattern shows the standard peak of CsPbBr3, confirming the successful preparation of CsPbBr3 quantum dot glass. Furthermore, the 110 crystal plane peak changes with the addition of AgBr, demonstrating that AgBr affects the structure of CsPbBr3.

[0056] The PL and absorption of CsPbBr3 quantum dot glass-ceramics were tested, and the results are as follows: Figure 4 As shown, the PL reaches its maximum value when the AgBr doping amount is 1.0.

[0057] Example 6

[0058] The CsPbBr3 quantum dot glass powder prepared in Example 3 was mixed with commercial PS masterbatch at a mass ratio of 5:1000, and the mixture was extruded at 220°C using a twin-screw extruder to obtain backlight panel A. Figure 5 As shown, the left image is the normal light image, and the right image is the violet light image.

[0059] The CsPbBr3 quantum dot glass powder prepared in Example 1 was mixed with commercial PS masterbatch at a mass ratio of 5:1000, and the mixture was extruded at 220°C using a twin-screw extruder to obtain backlight panel B.

[0060] Backlight panels A and B were tested under conditions of synergistic high humidity (RH=90%), high temperature (60 degrees Celsius), and strong blue light (200W / m²). 2 The light stability under aging conditions was as follows: Figure 6 As shown, backlight panel A has higher stability, and its fluorescence intensity remains above 90% after 1000 hours.

[0061] Example 7

[0062] The CsPbBr3 quantum dot glass powder prepared in Example 3 and the commercial phosphor K2SiF6:Mn were used. 4+ Mixed at a mass ratio of 3:2, and tested in an optical integrating sphere, the color gamut measured using a 450nm blue light chip is shown below. Figure 7 .

[0063] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. An AgBr-doped CsPbBr3 quantum dot microcrystalline glass, which is obtained by taking raw materials according to a glass formula, mixing and melting, water quenching, drying, grinding and sieving, heat treatment for crystallization, and cooling; characterized in that: The glass formulation consists of the following raw material components, wherein the content of each component is expressed in parts by weight: B2O324-26 portions; ZnO 14-16 parts; SiO2 22-24 parts; MgO2-4 parts; Al2O3 5-7 parts; CaO 1-3 parts; AgBr 0.5-1.5 parts; Cs2CO39-11 parts; PbBr25-7 parts; NaBr 9-11 parts.

2. The AgBr-doped CsPbBr3 quantum dot microcrystalline glass as described in claim 1, characterized in that: The glass formulation consists of the following raw material components: B2O3 25 portions; 15 portions of ZnO; 23 parts of SiO2; 3 parts MgO; Al2O36 portions; 2 parts CaO; AgBr 0.5-1.5 parts; 10 portions of Cs2CO3; PbBr2 6 parts; 10 parts of NaBr.

3. The AgBr-doped CsPbBr3 quantum dot glass-ceramic as described in claim 2, characterized in that: The glass formulation consists of the following raw material components: 25 portions of B2O3; 15 portions of ZnO; 23 parts of SiO2; 3 parts MgO; Al2O36 portions; 2 parts CaO; 1 part AgBr; 10 portions of Cs2CO3; PbBr2 6 parts; 10 parts of NaBr.

4. A method for preparing AgBr-doped CsPbBr3 quantum dot microcrystalline glass as described in any one of claims 1-3, characterized in that: The preparation method includes the following steps: (1) Weigh the raw material components according to the glass formula, mix the raw material components and grind them evenly, and then place them in a crucible; (2) Place the crucible obtained in step (1) into a lifting furnace, raise the temperature to 1100-1400 ℃, keep it at high temperature for 5-30 minutes, and then pour the glass melt into water for water quenching to obtain glass slag; (3) The glass slag obtained in step (2) is placed in an oven for drying at a temperature of 40-100℃ for 1-15 hours to obtain the precursor glass. (4) Grind and sieve the precursor glass obtained in step (3) to obtain precursor glass powder; then ball mill it through a 200-1000 mesh sieve to obtain precursor glass powder with different particle sizes. (5) The precursor glass powder obtained in step (4) is placed in a crystallization furnace, heated to 440-540℃ and held for 100-1000 min to allow CsPbBr3 to precipitate and grow in the glass, and then cooled with the furnace to obtain AgBr-doped CsPbBr3 quantum dot microcrystalline glass material.

5. The preparation method according to claim 4, characterized in that: In step (5), heat to 500°C and keep warm for 300 minutes.

6. The application of AgBr-doped CsPbBr3 quantum dot microcrystalline glass as described in any one of claims 1-3 in the preparation of liquid crystal display backlight panels.

7. The application as described in claim 6, characterized in that: The specific application involves mixing AgBr-doped CsPbBr3 quantum dot microcrystalline glass material with PS and then melting and extruding it to obtain a backlight panel.

8. The application as described in claim 7, characterized in that: The mass ratio of AgBr-doped CsPbBr3 quantum dot microcrystalline glass material to PS is 4-7:1000.

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