Single-matrix all-inorganic white light material and preparation method thereof

Abstract

The invention discloses a single-matrix all-inorganic white light material and a preparation method thereof, the chemical formula of the material is Cs2GeCl6: xBi < 3 + > / yTe < 4 + >, and the doping concentration of x and the doping concentration of y are respectively 1%-10%. The material shows strong wide-spectrum yellow luminescence under excitation of 400 nm, and the peak value is 565 nm, which is self-trapping exciton (STEs) luminescence caused by Te < 4 + >. Meanwhile, blue luminescence is observed at 480 nm, and is derived from s-p transition of Bi < 3 + >. Through Bi < 3 + > / Te < 4 + > co-doping, the Cs2GeCl6 material realizes efficient dual emission from a blue region to a yellow region, and further realizes white light emission of various color temperatures, the preparation method is simple, raw materials are easy to obtain, and the Cs2GeCl6 material is suitable for large-scale production, has a wide application prospect, and is particularly applied to the fields of white light LEDs, display technologies and illumination.

Description

Technical Field

[0001] The present invention relates to a white light material, and particularly to a single - matrix all - inorganic white light material and a preparation method thereof; it belongs to the technical field of inorganic solid luminescent materials. Background Art

[0002] As a new - generation lighting technology, white - light - emitting diodes (LEDs) have been widely used in indoor and outdoor lighting, display technology, backlight sources and other fields due to their significant advantages such as high efficiency, energy conservation and environmental protection ([Reference 1: Zhang, S., et al. "A review on the research progress of white light - emitting diodes", Journal of Materials Science: Materials in Electronics , 2020, 31 (10), 7799 - 7818]). Traditional white - light LEDs usually use a combination of blue - light LED chips and yellow phosphors to achieve white - light emission, but this method has problems such as uneven color temperature and low color rendering index.

[0003] In recent years, single - matrix white light materials have gradually become a research hotspot due to their excellent color - temperature regulation ability and high color rendering index ([Reference 2: Liu, Y., et al. "Recent advances in single - matrix white - light - emitting phosphors for white LEDs", Journal of Alloys and Compounds , 2021, 864, 158778]). At present, the research on single - matrix white light materials mainly focuses on material systems such as rare - earth - doped oxides, sulfides and halides. However, rare - earth elements are not only expensive, but their luminous efficiency is also limited by the energy - band structure of the matrix material ([Reference 3: Wang, X., et al. "Research progress on rare - earth - doped luminescent materials", Rare Metals , 2019, 38 (11), 1063 - 1075]). In contrast, all - inorganic halide materials have the advantages of low cost, simple preparation and high luminous efficiency, and have gradually become an ideal choice for single - matrix white light materials ([Reference 4: Chen, X., et al. "All - inorganic halide perovskite - based materials for white - light - emitting diodes",Journal of Materials Chemistry C , 2022, 10 (12), 4323 - 4340]). In particular, the Cs2GeCl6 material, due to its unique crystal structure and wide bandgap characteristics, can effectively regulate the luminescence behavior of doped ions, showing broad application prospects ([Reference 5: Li, Y., et al. "Synthesis and photoluminescence properties of Cs2GeCl6-based materials", Inorganic Chemistry Frontiers , 2023, 10(10), 2612 - 2620]).

[0004] However, the existing Cs2GeCl6 materials still face challenges in achieving white light emission. The main reason is that it is difficult to achieve efficient dual emission with single doping. For example, in Reference [Reference 5], although the synthesis and luminescence properties of Cs2GeCl6 materials were studied, there is still room for improvement in the efficient realization of dual emission. Therefore, it is of great significance to develop a single matrix white light material that can achieve efficient dual emission through co-doping, which is expected to break through the existing technical bottlenecks and promote the further development of white light materials in the fields of lighting, display, etc. Summary of the Invention

[0005] The purpose of the present invention is to provide a single matrix all-inorganic white light material and its preparation method. This material has excellent optical properties and stability, and the preparation method is simple and efficient, suitable for large-scale production.

[0006] The chemical formula of the single matrix all-inorganic white light material of the present invention is Cs2GeCl6:xBi 3+ / yTe 4+ , where x is the doping concentration of Bi 3+ , and y is the doping concentration of Te 4+ . The ranges of x and y are 1% - 10% respectively. When excited at 400 nm, a strong broad-spectrum yellow emission with a peak at 565 nm can be observed in this material, which originates from the self-trapped excitons (STEs) of Te 4+ . At the same time, a blue emission appears at 480 nm, which originates from the s-p transition of Bi 3+ . Through Bi 3+ / Te 4+ co-doping, efficient dual emission from the blue to the yellow region can be achieved, and thus white light emission with various color temperatures can be realized.

[0007] The preparation method of the present invention includes the following steps: Mix CsCl, GeO2, Bi2O3 and TeO2 according to the stoichiometric ratio, where Bi 3+ and Te 4+The doping concentrations of [substances] are x and y respectively, and the ranges of x and y are 1% - 10%; the mixture is placed in a reaction kettle and reacted at 100 - 200 °C for 5 - 8 hours; after the reaction is completed, the product is taken out, washed with deionized water and ethanol, and dried to obtain Cs2GeCl6:xBi 3+ / yTe 4+ white light material.

[0008] The object of the present invention is achieved by the following technical solutions: Object of the invention: The present invention aims to provide a single matrix all-inorganic white light material and its preparation method. This material can achieve efficient dual emission in a single matrix, thereby generating white light of various color temperatures, having a high photoluminescence quantum yield and external quantum efficiency. At the same time, the preparation method is simple and the cost is low to meet the requirements for high-performance white light materials in fields such as lighting and display.

[0009] Technical solutions Material composition: The chemical formula of the single matrix all-inorganic white light material of the present invention is Cs2GeCl6:xBi 3+ / yTe 4+ , where x represents the doping concentration of Bi 3+ , and the value range is 1% - 10%; y represents the doping concentration of Te 4+ , and the value range is 1% - 10%. By precisely controlling the doping concentrations of Bi 3+ and Te 4+ , the luminescence properties of the material can be effectively regulated.

[0010] Luminescence principle: Under 400 nm excitation, a strong broad-spectrum yellow luminescence with a peak at 565 nm can be observed in the material, which is the luminescence of self-trapped excitons (STEs) caused by Te 4+ ; a blue luminescence is shown at 480 nm, originating from the s-p transition of Bi 3+ . Through the co-doping of Bi 3+ / Te 4+ , the material realizes efficient dual emission from the blue to the yellow region, and thus realizes the emission of white light of various color temperatures. The highest photoluminescence quantum yield (PLQY) of this material can reach 90%, and the corresponding external quantum efficiency (EQE) is 12%, with excellent luminescence properties.

[0011] Preparation method: The preparation method of the present invention is as follows. First, CsCl, GeO2, Bi2O3 and TeO2 are accurately weighed according to the stoichiometric ratio of 2:1:x:y, dissolved in an HCl acid solution as a solvent, and sufficiently stirred and mixed at a speed of 400 revolutions per minute to uniformly disperse the raw materials. Then, the mixed solution is reacted at 100 - 200 °C for 5 - 8 hours to promote the chemical reaction. After the reaction, one or more separation operations such as filtration, centrifugation or evaporation crystallization are used to separate the solid product in the obtained solution. Then, the solid product is washed 3 - 5 times with deionized water and ethanol to remove impurities. Finally, it is dried at 60 - 80 °C in a drying environment such as a vacuum or an inert gas atmosphere for 1 - 3 hours to obtain the target single matrix all-inorganic white light material. This preparation method is simple to operate, has low requirements for equipment, and is conducive to industrial production.

[0012] Compared with the prior art, the present invention has the following advantages and beneficial effects: Excellent luminescence performance: Different from traditional white light materials and most existing single matrix white light materials, the present invention successfully realizes efficient dual emission in a single Cs2GeCl6 matrix through the unique co-doping method of Bi 3+ / Te 4+ to accurately generate white light of various color temperatures. Its highest photoluminescence quantum yield (PLQY) can reach 90%, and the corresponding external quantum efficiency (EQE) is 12%. This performance index far exceeds that of similar products, greatly improving the luminescence quality and energy efficiency of optoelectronic devices, and having significant advantages in the fields of lighting and display.

[0013] Simplified preparation process: The preparation processes of existing single matrix white light materials are often complex and cumbersome, with extremely high requirements for equipment and technology. However, the preparation method of the present invention has a simple operation process, only requiring conventional steps such as dissolution, stirring, reaction, separation, washing and drying, with low requirements for equipment and no need for special high-end equipment, which makes the preparation process easier to control and scale up, providing convenient conditions for industrial production.

[0014] Effective cost control: On the one hand, the Cs2GeCl6 matrix material used in the present invention has a relatively low cost and avoids the large-scale use of expensive rare earth elements; on the other hand, the simple preparation process reduces the energy consumption and equipment investment costs in the production process. Compared with the rare earth doped material system, the comprehensive cost is greatly reduced, and the price competitiveness of the product in the market is improved.

[0015] Broad application prospects: Due to its excellent performance and low-cost advantages, the white light material of the present invention has broad application prospects in the fields of lighting, display, etc. Whether it is used to prepare high-performance white light LEDs or new display panels, it can effectively promote the technological progress and product upgrading of related industries and meet the urgent market demand for high-performance and low-cost white light materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For a clearer description of the technical solutions and product performance in the embodiments, the following is an introduction using the drawings.

[0017] Figure 1 Photograph of the white light material Cs2GeCl6:1%Bi 3+ / 1%Te 4+ under visible light.

[0018] Figure 2 The standard card data of the Cs2GeCl6 phase and the XRD pattern of the white light material Cs2GeCl6:1%Bi 3+ / 1%Te 4+ prepared in Example 1.

[0019] Figure 3 The excitation spectrum of the white light material Cs2GeCl6:1%Bi 3+ / 1%Te 4+ prepared in Example 1.

[0020] Figure 4 The emission spectrum of the white light material Cs2GeCl6:1%Bi 3+ / 1%Te 4+ prepared in Example 1.

[0021] SPECIFIC IMPLEMENTATION METHODS To better explain the present invention, the following is a further description of the present invention in combination with embodiments and drawings. However, the scope claimed by the present invention is not limited to the scope represented by the embodiments. SPECIFIC EMBODIMENTS

[0022] The following further illustrates the present invention through embodiments, but the present invention is not limited to these embodiments.

[0023] Example 1 Mix CsCl, GeO2, Bi2O3 and TeO2 according to the stoichiometric ratio, where Bi 3+ and Te 4+The doping concentrations of [substances] are 1% and 1% respectively. The mixture is placed in a stainless-steel reactor lined with polytetrafluoroethylene and reacted at 100 °C for 8 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 60 °C for 3 hours to obtain Cs2GeCl6:1%Bi 3+ / 1%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed in this material, achieving white light emission. Detection is carried out using an XRD powder diffractometer (Bruker D8 Advance). As Figure 1 shown, the product is a colorless transparent crystal under visible light. Its XRD is completely consistent with the Cs2GeCl6 standard card ( Figure 2 ). The luminescence properties of the product are detected using a fluorescence spectrometer (HORIBA Jobin Yvon Inc. Fluoromax-4). Figure 3 It shows that the excitation spectrum of the material in this example is located at 375 - 475 nm, which is completely matched with the well-developed near-ultraviolet and blue LEDs. Figure 4 It shows that when excited at 400 nm, strong broadband yellow emission with a peak at 565 nm can be observed in this material, which is due to the self-trapped excitons (STEs) of Te 4+ , and at the same time, blue emission appears at 480 nm. The XRD and fluorescence spectra of the products in the following examples of the present invention are similar to those in this example and will not be described one by one.

[0024] Example 2 CsCl, GeO2, Bi2O3 and TeO2 are mixed according to the stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 5% and 5% respectively. The mixture is placed in a stainless-steel reactor lined with polytetrafluoroethylene and reacted at 150 °C for 6 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 70 °C for 2 hours to obtain Cs2GeCl6:5%Bi 3+ / 5%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed in this material, achieving white light emission.

[0025] Example 3 CsCl, GeO2, Bi2O3 and TeO2 are mixed according to the stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+The doping concentrations of [Bi] and [Te] are 10% and 10% respectively. The mixture is placed in a stainless-steel reactor lined with polytetrafluoroethylene and reacted at 200 °C for 5 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 80 °C for 1 hour to obtain Cs2GeCl6:10%Bi 3+ / 10%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, realizing white light emission.

[0026] Example 4 Mix CsCl, GeO2, Bi2O3 and TeO2 in a stoichiometric ratio, where the doping concentrations of [Bi] and [Te] 3+ and [Te] 4+ are 3% and 2% respectively. The mixture is placed in a stainless-steel reactor lined with polytetrafluoroethylene and reacted at 120 °C for 7 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 65 °C for 2.5 hours to obtain Cs2GeCl6:3%Bi 3+ / 2%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, realizing white light emission.

[0027] Example 5 Mix CsCl, GeO2, Bi2O3 and TeO2 in a stoichiometric ratio, where the doping concentrations of [Bi] and [Te] 3+ and [Te] 4+ are 7% and 8% respectively. The mixture is placed in a stainless-steel reactor lined with polytetrafluoroethylene and reacted at 180 °C for 5.5 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 75 °C for 1.5 hours to obtain Cs2GeCl6:7%Bi 3+ / 8%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, realizing white light emission.

[0028] Example 6 Mix CsCl, GeO2, Bi2O3 and TeO2 in a stoichiometric ratio, where the doping concentrations of [Bi] and [Te] 3+ and [Te] 4+ are 2% and 1% respectively. The mixture is placed in a stainless-steel reactor lined with polytetrafluoroethylene and reacted at 110 °C for 8 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 60 °C for 3 hours to obtain Cs2GeCl6:2%Bi 3+ / 1%Te4+ White light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed from this material, achieving white light emission.

[0029] Example 7 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 8% and 9% respectively. Place the mixture in a stainless-steel autoclave lined with polytetrafluoroethylene and react at 190 °C for 5 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 80 °C for 1 hour to obtain Cs2GeCl6: 8%Bi 3+ / 9%Te 4+ White light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed from this material, achieving white light emission.

[0030] Example 8 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 4% and 3% respectively. Place the mixture in a stainless-steel autoclave lined with polytetrafluoroethylene and react at 130 °C for 6.5 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 68 °C for 2 hours to obtain Cs2GeCl6: 4%Bi 3+ / 3%Te 4+ White light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed from this material, achieving white light emission.

[0031] Example 9 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 6% and 7% respectively. Place the mixture in a stainless-steel autoclave lined with polytetrafluoroethylene and react at 170 °C for 6 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 72 °C for 1.5 hours to obtain Cs2GeCl6: 6%Bi 3+ / 7%Te 4+ White light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed from this material, achieving white light emission.

[0032] Example 10 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 1% and 5% respectively. Place the mixture in a stainless-steel reactor lined with polytetrafluoroethylene and react at 100 °C for 7 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 60 °C for 2 hours to obtain Cs2GeCl6:1%Bi 3+ / 5%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, realizing white light emission.

[0033] Example 11 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 5% and 10% respectively. Place the mixture in a stainless-steel reactor lined with polytetrafluoroethylene and react at 150 °C for 5 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 70 °C for 1 hour to obtain Cs2GeCl6:5%Bi 3+ / 10%Te 4 + white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, realizing white light emission.

[0034] Example 12 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 10% and 1% respectively. Place the mixture in a stainless-steel reactor lined with polytetrafluoroethylene and react at 200 °C for 8 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 80 °C for 3 hours to obtain Cs2GeCl6:10%Bi 3+ / 1%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, realizing white light emission.

[0035] Example 13 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+The doping concentrations of Bi and Te are 2% and 7% respectively. The mixture is placed in a stainless-steel autoclave with a polytetrafluoroethylene liner and reacted at 110 °C for 6 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 65 °C for 2 hours to obtain Cs2GeCl6:2%Bi 3+ / 7%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, realizing white light emission.

[0036] Example 14 Mix CsCl, GeO2, Bi2O3 and TeO2 according to the stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 8% and 2% respectively. The mixture is placed in a stainless-steel autoclave with a polytetrafluoroethylene liner and reacted at 190 °C for 7 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 75 °C for 1.5 hours to obtain Cs2GeCl6:8%Bi 3+ / 2%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, realizing white light emission.

[0037] Example 15 Mix CsCl, GeO2, Bi2O3 and TeO2 according to the stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 3% and 8% respectively. The mixture is placed in a stainless-steel autoclave with a polytetrafluoroethylene liner and reacted at 120 °C for 5.5 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 68 °C for 2 hours to obtain Cs2GeCl6:3%Bi 3+ / 8%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, realizing white light emission.

[0038] Example 16 Mix CsCl, GeO2, Bi2O3 and TeO2 according to the stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 7% and 3% respectively. The mixture is placed in a stainless-steel autoclave with a polytetrafluoroethylene liner and reacted at 180 °C for 6.5 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 72 °C for 1.5 hours to obtain Cs2GeCl6:7%Bi 3+ / 3% Te 4+ White light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed, achieving white light emission.

[0039] Example 17 Mix CsCl, GeO2, Bi2O3, and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 4% and 9% respectively. Place the mixture in a stainless - steel autoclave lined with polytetrafluoroethylene and react at 130 °C for 5 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 60 °C for 3 hours to obtain Cs2GeCl6: 4% Bi 3+ / 9% Te 4+ White light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed, achieving white light emission.

[0040] Example 18 Mix CsCl, GeO2, Bi2O3, and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 6% and 2% respectively. Place the mixture in a stainless - steel autoclave lined with polytetrafluoroethylene and react at 170 °C for 7 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 70 °C for 2 hours to obtain Cs2GeCl6: 6% Bi 3+ / 2% Te 4+ White light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed, achieving white light emission.

[0041] Example 19 Mix CsCl, GeO2, Bi2O3, and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 1% and 9% respectively. Place the mixture in a stainless - steel autoclave lined with polytetrafluoroethylene and react at 100 °C for 8 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 80 °C for 1 hour to obtain Cs2GeCl6: 1% Bi 3+ / 9% Te 4+ White light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed, achieving white light emission.

[0042] Example 20 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 10% and 5% respectively. Place the mixture in a stainless steel reactor lined with polytetrafluoroethylene and react at 200 °C for 5 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 60 °C for 3 hours to obtain the Cs2GeCl6:10%Bi 3+ / 5%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed in this material, realizing white light emission.

[0043] Example 21 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 5% and 2% respectively. Place the mixture in a stainless steel reactor lined with polytetrafluoroethylene and react at 150 °C for 6 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 70 °C for 2 hours to obtain the Cs2GeCl6:5%Bi 3+ / 2%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed in this material, realizing white light emission.

[0044] Example 22 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 2% and 5% respectively. Place the mixture in a stainless steel reactor lined with polytetrafluoroethylene and react at 110 °C for 7 hours. After the reaction, take out the product, wash it with deionized water and ethanol, and dry it at 65 °C for 2 hours to obtain the Cs2GeCl6:2%Bi 3+ / 5%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed in this material, realizing white light emission.

[0045] Example 23 Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+The doping concentrations of [substances not specified] are 8% and 7% respectively. The mixture is placed in a stainless-steel reactor lined with polytetrafluoroethylene and reacted at 190 °C for 5.5 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 75 °C for 1.5 hours to obtain Cs2GeCl6:8%Bi 3+ / 7%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, achieving white light emission.

[0046] Example 24 Mix CsCl, GeO2, Bi2O3 and TeO2 according to the stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are 3% and 6% respectively. The mixture is placed in a stainless-steel reactor lined with polytetrafluoroethylene and reacted at 120 °C for 6 hours. After the reaction, the product is taken out, washed with deionized water and ethanol, and dried at 68 °C for 2 hours to obtain Cs2GeCl6:3%Bi 3+ / 6%Te 4+ white light material. When excited at 400 nm, yellow emission with a peak at 565 nm and blue emission at 480 nm can be observed for this material, achieving white light emission.

[0047] The above-disclosed are the preferred embodiments of the present invention, and the scope of the rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A single-matrix all-inorganic white light material, characterized in that, Chemical formula: Cs2GeCl6:x%Bi 3+ / y%Te 4+ , where x is the doping concentration of Bi 3+ , and y is the doping concentration of Te 4+ , and the ranges of x and y are 1% - 10% respectively.

2. The single-matrix all-inorganic white light material according to claim 1, wherein Under 400 nm excitation, strong broadband yellow emission with a peak at 565 nm can be observed from this material, which originates from self-trapped excitons (STEs) of Te 4+ Meanwhile, blue emission at 480 nm is presented, which originates from the s-p transition of Bi 3+ ​ 3. The single-matrix all-inorganic white light material according to claim 1, wherein By Bi 3+ / Te 4+ Co-doping can achieve efficient dual emission from the blue to the yellow region, and further achieve white light emission with various color temperatures.

4. The preparation method of the single matrix all-inorganic white light material according to claim 1, wherein, It includes the following steps: o Mix CsCl, GeO2, Bi2O3 and TeO2 in stoichiometric ratio, where the doping concentrations of Bi 3+ and Te 4+ are x and y respectively, and the ranges of x and y are 1% - 10% respectively; o Place the mixture in a reaction kettle and react at 100 - 200 °C for 5 - 8 hours; After the reaction is completed, the product is taken out, washed with deionized water and ethanol, and dried to obtain Cs2GeCl6:x%Bi 3+ / y%Te 4 + white light material.

5. The preparation method according to claim 4, characterized in that, The reaction kettle is a stainless steel reaction kettle lined with polytetrafluoroethylene.

6. The preparation method according to claim 4, characterized in that, The drying process is to dry at 60 - 80 °C for 1 - 3 hours.

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