Large-size perovskite glass based on ultrasonic stirring homogenization and preparation method thereof

Abstract

The invention relates to the technical field of perovskite glass, in particular to large-size perovskite glass based on ultrasonic stirring homogenization and a preparation method of the large-size perovskite glass. The glass is prepared from the following components in molar ratio: 50-70% of glass network main body, 5-15% of ZnO, 5-15% of MO, 5-10% of Cs2O and 5-10% of sodium salt, wherein the MO is any one of MgO, CaO, SrO and BaO. The method comprises the following steps: pouring a uniformly mixed material into a quartz glass crucible for melting, and then carrying out annealing treatment and heat treatment to obtain the controllable crystallization and uniform large-size perovskite glass. The large-size perovskite glass prepared by the method disclosed by the invention is controllable in crystallization, and perovskite crystals are uniformly distributed in the glass; the obtained large-size perovskite glass has the transmittance of 90% or above, and the light-emitting quantum efficiency of blocky glass reaches 70% or above.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of perovskite glass, more particularly to a large-size perovskite glass based on ultrasonic stirring homogenization and a preparation method thereof. BACKGROUND

[0002] Perovskite materials are attracting much attention due to their unique ABX3-type crystal structure (where A is a cesium ion, B is a lead / tin metal cation, and X is a halide anion). In this structure, the B-site metal cation and the X-site halide anion usually form a regular octahedral coordination, and the A-site ion fills the cubic void. This flexible ion arrangement provides significant control space for the material, enabling it to have excellent performance such as tunable emission wavelength, high luminescence quantum efficiency, and narrow emission bandwidth, and has wide application prospects in high-energy photon detection, three-dimensional information storage, and high-precision display.

[0003] Current research on perovskite materials mainly focuses on three forms: powder, liquid, and single crystal. However, all three forms face stability challenges: powder materials are extremely sensitive to humid and hot environments and are prone to degradation, resulting in a short actual service life; liquid materials have some processing convenience but pose a risk of decomposition and phase separation, posing a threat to the health of operators and the ecological environment; single crystal materials have superior optical performance due to fewer defects, but their humidity and heat stability is still insufficient, and the long preparation cycle greatly limits the expansion of practical application scenarios.

[0004] Fortunately, the emergence of perovskite glass materials has effectively solved the problem of poor stability of perovskite. Perovskite glass, which uniformly precipitates perovskite nanocrystals (CsPbCl3, CsPbBr3, CsPbI3, etc.) in glass, achieves high-efficiency luminescence. The dense glass network structure effectively isolates moisture and oxygen in the air, providing a good barrier for perovskite crystals and significantly slowing down the decomposition rate of perovskite, fundamentally improving the humidity and heat stability of the material. At the same time, the high hardness of the glass can resist external stress impact, reducing the risk of performance degradation due to mechanical damage. In addition, the encapsulation of glass can effectively inhibit the migration and leakage of lead elements, further reducing the potential harm to the environment and human health. Therefore, the preparation of high-quality perovskite glass is crucial for advancing the practical application process of perovskite materials.

[0005] Whether the perovskite glass is large in size and uniform or not directly determines whether it can be applied on a large scale. However, in the preparation process of the perovskite glass, the halide components (NaCl, PbBr, CsI, etc.) and the glass network former components (SiO2, GeO2, P2O5, etc.) can both form a glass network, and are prone to phase separation, which is not conducive to the formation of uniform perovskite glass. In addition, Pb and Cs in the perovskite glass have a large difference in density from Si, and in the sintering process, ions with high density tend to sink to the bottom, causing the glass to be seriously non-uniform, leading to difficulty in the precipitation of perovskite in the glass or uneven crystallization, especially in the preparation of large-size perovskite glass. Therefore, the preparation of large-size perovskite glass with good uniformity has become a big problem in the preparation of perovskite glass. SUMMARY

[0006] The purpose of the present application is to provide a large-size perovskite glass based on ultrasonic stirring homogenization and a preparation method thereof. Through this preparation method, a perovskite glass with large size and good uniformity is prepared, so as to facilitate the application of the perovskite glass in the relevant field.

[0007] As to the specific preparation method of the present application, specifically, after the glass liquid is fully melted, the glass liquid is continuously vibrated by an ultrasonic platform, and the glass liquid is continuously stirred by a stirring rod. Under the combined action of ultrasonic and stirring, the halide ions (F - , Cl - , Br - , I - ) in the upper layer of the glass liquid and the Pb 2+ , Cs + ions in the lower layer can be fully and uniformly mixed, ensuring that all components are uniformly distributed in the glass network structure. When the glass liquid is clear and transparent, the glass liquid is quickly poured onto a graphite plate to obtain a precursor glass without perovskite crystal precipitation. The precursor glass is heat-treated at a suitable temperature for a certain period of time to obtain a large-size perovskite glass with controllable crystallization and uniform crystal size.

[0008] To achieve the above-mentioned purpose, the following technical solutions are adopted: A large-size perovskite glass based on ultrasonic stirring homogenization, which is composed of the following components in terms of molar ratio: 50-70% of a glass network main body, 5-15% of ZnO, 5-15% of MO, 5-10% of Cs2O, and 5-10% of a sodium salt. Among them, MO is any one of MgO, CaO, SrO and BaO.

[0009] Further, the glass network main body is one or two of SiO2, GeO2, B2O3, TeO2 and P2O5.

[0010] Further, the sodium salt is any one or two of NaF, NaCl, NaBr, NaI.

[0011] A preparation method of large-size perovskite glass based on ultrasonic stirring homogenization, comprising the following steps: (1) preparing each component according to the component allocation ratio; designing a perovskite glass component allocation formula; (2) grinding and mixing each component in a grinding bowl until uniform; (3) pouring the uniformly mixed mixture into a quartz glass crucible, adding a preheated cover, and placing it in a high-temperature smelting furnace for melting; specifically, slowly heating to 1200-1300℃ for 90-150min; then ultrasonic vibration and stirring of the molten glass liquid through a stirring rod until the glass liquid is clear and transparent, quickly pouring the glass liquid onto a graphite plate to obtain a precursor glass without perovskite crystal precipitation; ultrasonic power 500-1000W; (4) transferring the precursor glass to an annealing furnace for heat treatment to eliminate internal stress and prevent glass cracking; annealing specifically involves heating the precursor glass to 400-450℃ for 5-10h; (5) heat treating the annealed precursor glass at 480-550℃ for 5-20h to obtain controllable crystallization and uniform large-size perovskite glass.

[0012] The technical solution of the present application is mainly used to solve the industry problem of difficult preparation of large-size and high-uniformity perovskite glass. The scheme sets a specific molar ratio of SiO2 / GeO2 / B2O3, ZnO, SrO, sodium salt, Cs2O, PbO combination, and cooperates with the preparation method of the present application to achieve it. Especially, the introduction of a specific power ultrasonic stirring in the smelting process has not been completely disclosed in the prior art. The specific component combination and unique process steps constitute a new technical solution.

[0013] The background art clearly points out a long-standing technical bottleneck: it is extremely difficult to prepare large-size, high-uniformity perovskite glasses due to the phase separation tendency of halide and network former and the settling effect of high-density ions such as Pb and Cs. This is a problem recognized by those skilled in the art. The scheme is not simply mixing known components. The introduction of ZnO and SrO (MO) plays a key role. ZnO can act as both a network former and an extra-network body in the glass, effectively reducing the melting temperature, improving chemical stability, and inhibiting crystallization (for precursor glasses). Alkaline earth metal oxides such as SrO can adjust the glass network structure, provide free oxygen, reduce the melt viscosity, and help subsequent uniform crystallization. The addition of sodium salt (such as NaBr) not only provides a halogen source (Br), but also acts as a flux, significantly reducing the melting temperature of the glass and reducing the loss of volatile components such as Pb and Cs at high temperatures, which is crucial for maintaining the accuracy and uniformity of the formulation.

[0014] Ultrasonic stirring homogenization is the most core and prominent creativity of the scheme. Ultrasonic waves in molten glass liquid will produce "acoustic cavitation" effect, that is, the violent formation, growth and instantaneous collapse of micro-bubbles in the liquid, producing local extreme high temperature, high pressure and strong shock wave. Through the cooperation of ultrasonic waves, powerful homogenization is achieved: this powerful physical force can effectively break up the possible phase separation area and force the ions with large density difference (such as Br - in the upper layer and Pb 2+ , Cs + in the lower layer) to flow and mix forcibly, fundamentally solving the problems of component settling and macroscopic phase separation; at the same time, it can also promote dissolution and clarification, and the cavitation effect can accelerate the dissolution of raw material particles and the exclusion of bubbles, so that the "clear and transparent" glass liquid is obtained faster, which is the premise of obtaining high-quality precursor glass. The application of ultrasonic-assisted processing technology to the melting process of perovskite glass is not a conventional or well-known means in the art, and it reflects the inventors' deep understanding of the specific technical problem and the non-obvious technical means proposed.

[0015] According to the performance results of the products prepared by the examples, the method successfully prepared large-size glass samples with a diameter of more than 16 cm, which is a great breakthrough in itself. And the prepared products have excellent performance: transmittance > 90%, luminescence quantum efficiency > 70%, which proves that the size of the perovskite crystals (CsPbBr3) precipitated inside is uniform, the distribution is dispersed, the defects are few, and the optical quality is extremely high. Controllable crystallization is achieved: the precursor glass is completely amorphous (XRD broad peak), and after heat treatment, perovskite crystal phase can be directionally precipitated, which shows that the precursor glass prepared by the method has excellent uniformity and crystallization potential.

[0016] Compared with the prior art, the beneficial effects of the present application are: The large-size perovskite glass prepared by the method has a crystallization that can be controlled, and perovskite crystals are uniformly distributed in the glass. The large-size perovskite glass prepared by the method has a transmittance of up to 90% or more, and the luminescent quantum efficiency of the block glass reaches 70% or more. The application provides a novel preparation method of large-size perovskite glass, and provides a good reference for the preparation of more different system glasses. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A schematic diagram for preparing large-size perovskite glass by using the ultrasonic stirring homogenization method.

[0018] Figure 2 XRD diagrams of the precursor glass and the perovskite glass in Example 1.

[0019] Figure 3 Photos of the large-size precursor glass and the perovskite glass in Example 1.

[0020] Figure 4 A transmittance diagram of the large-size perovskite glass in Example 1.

[0021] Figure 5 A luminescent quantum efficiency diagram of the large-size perovskite glass in Example 1.

[0022] Figure 6 A luminescent spectrum diagram of the large-size perovskite glass in Example 2.

[0023] Figure 7 Photos of the large-size precursor glass and the perovskite glass in Example 2.

[0024] Figure 8 An XRD diagram of the perovskite glass in Example 2.

[0025] Figure 9 A luminescent spectrum diagram of the large-size perovskite glass in Example 2.

[0026] Figure 1 Medium: 1 motor, 2 stirring rod, 3 electric furnace, 4 crucible, 5 ultrasonic instrument, 6 crucible cover, 7 glass liquid. DETAILED DESCRIPTION

[0027] The technical solutions of the application are further described in detail in the following specific embodiments.

[0028] Example 1: A large-size perovskite glass based on ultrasonic stirring homogenization is prepared according to the following steps: (1) The glass adopts the following formula: component molar percentage SiO2: 35% B2O3: 35% ZnO: 5% SrO: 5% NaBr: 10% Cs2O: 5% PbO: 5 (2) High purity powdery raw materials 500 g are weighed according to the component formula, and are mixed uniformly in a marver mortar; (3) The mixed material is poured into a 1000 ml alumina crucible, a cover is added, and the crucible is placed in a high-temperature smelting furnace, slowly heated to 1200 DEG C and kept for 90 min, then a stirring rod is added, ultrasonic vibration is started and fast stirring is started, until black smoke is not emitted and the glass liquid is clear, the glass liquid is taken out, quickly poured on a graphite plate, and a large-size precursor glass without crystal precipitation with a diameter of 16.5 cm is obtained; (4) The large-size precursor glass is kept at 400 DEG C for 10 h to eliminate part of the stress and prevent the glass from cracking; (5) The annealed large-size precursor glass is kept at 530 DEG C for 10 h for heat treatment, and a large-size green perovskite glass with controllable and uniform crystal precipitation is obtained. The prepared large-size perovskite glass is mirror-polished on both sides, and is used for subsequent tests.

[0029] The large-size perovskite glass prepared above is subjected to XRD test, and the XRD pattern is shown in the figure. Figure 2 The precursor glass is amorphous with wide shoulder peaks, and the heat-treated glass is CsPbBr3 crystal, and the crystal precipitation is controllable.

[0030] The actual object is shown in the figure. Figure 3 (a), the large-size precursor glass prepared by the application is colorless and transparent; as shown in Figure 3 (b), the large-size perovskite glass prepared by the application is blue-green, transparent and clear, and the crystal precipitation is uniform, which proves that the ultrasonic stirring and homogenization method can prepare a large-size perovskite glass with uniform crystal precipitation.

[0031] The large-size perovskite glass prepared in Example 1 is subjected to light transmittance test, and the result is shown in the figure. Figure 4 The transmittance of the prepared large-size perovskite glass can reach more than 90%.

[0032] The large-size perovskite glass prepared in Example 1 is subjected to luminescence spectrum test, and the result is shown in the figure. Figure 5 The prepared large-size perovskite glass has visible luminescence, and the luminescence peak center is 516 nm.

[0033] The large-size perovskite glass prepared in Example 1 is subjected to luminescence quantum test, and the result is shown in the figure. Figure 6As shown, the prepared large-size perovskite glass has a luminescence quantum efficiency of more than 70%.

[0034] In this scheme, the device used is as shown in Figure 1 As shown, the furnace is provided with a crucible, the crucible is provided with a crucible cover, the crucible is arranged on an ultrasonic instrument, the crucible is driven by a stirring rod through a motor, and the crucible is placed with glass liquid.

[0035] Example 2: A large-size perovskite glass based on ultrasonic stirring homogenization is prepared according to the following steps: (1) The glass adopts the following formula: the component molar percentage is: SiO2: 35% B2O3: 35% ZnO: 5% SrO: 5% NaBr: 5% NaI: 5% Cs2O: 5% PbO: 5 (2) 500 g of high-purity powdered raw materials is weighed according to the component formula and mixed uniformly in an agate mortar; (3) Pour the uniformly mixed material into a 1000 ml alumina crucible, add a cover, and place it in a high-temperature smelting furnace. Slowly heat to 1200℃ and keep for 90 min, then put in a stirring rod, turn on the ultrasonic vibration and fast stirring, until the black smoke is not out, the glass liquid is clear, take out the glass liquid, quickly pour on the graphite plate, get a large-size precursor glass without crystal precipitation, the diameter is up to 17 cm; (4) The large-size precursor glass is kept at 400℃ for 10h to eliminate part of the stress and prevent the glass from cracking; (5) The annealed large-size precursor glass is kept at 530℃ for 10h for heat treatment, and a large-size red light perovskite glass with controllable and uniform crystallization is obtained. The glass photo is as shown in Figure 7 As shown. The prepared large-size perovskite glass is mirror polished on both sides for subsequent testing.

[0036] The material and optical performance of the large-size red light perovskite are characterized.

[0037] As shown in the XRD pattern of Figure 8 CsPbBr3 perovskite crystals are precipitated in the prepared bulk glass. The luminescence spectrum of the glass is as shown in Figure 9 Red light emission is observed in the glass, and the luminescence center is located at 678 nm.

[0038] The above examples are used to explain the present application, but not to limit the application, any modification and change made to the present application within the spirit and scope of the application and the claims of the application should be included in the protection scope of the present application.

Claims

1. A large size perovskite glass homogenized based on ultrasonic agitation, characterized by: According to the mole ratio consists of: Glass network 50-70%, ZnO 5-15%, MO 5-15%, Cs2O 5-10%, sodium salt 5-10%; Among them: MO is any one of MgO, CaO, SrO, BaO.

2. The large-size perovskite glass based on ultrasonic stirring homogenization according to claim 1, characterized in that: The glass network is one or two of SiO2, GeO2, B2O3, TeO2, P2O5.

3. The large size perovskite glass based on ultrasonic agitation homogenization according to claim 1, characterized in that: The sodium salt is any one or two of NaF, NaCl, NaBr, Nal.

4. The method of claim 1, wherein the method is characterized by: The preparation method comprises the following steps: (1) Prepare each component according to the component allocation ratio; design the perovskite glass component allocation formula; (2) Grind and mix each component in a mortar until uniform; (3) Pour the mixed material into a quartz glass crucible, add a preheated lid, and put it into a high-temperature smelting furnace for smelting; Specifically, slowly heat to 1200-1300℃ for 90-150min; Then the molten glass liquid is ultrasonically vibrated and stirred by a stirring rod until the glass liquid is clear and transparent, the glass liquid is quickly poured onto a graphite plate to obtain a precursor glass without perovskite crystal precipitation; (4) Transfer the precursor glass to an annealing furnace for heat treatment to eliminate internal stress and prevent the glass from cracking; annealing is specifically heating the precursor glass to 400-450℃ for 5-10h; (5) Heat the annealed precursor glass at 480-550℃ for 5-20h to obtain a controllable and uniform large-size perovskite glass.

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