A non-lead-based perovskite glass-ceramic material, a preparation method and applications thereof

Abstract

The application discloses a non-lead halide perovskite microcrystalline glass material and a preparation method and application thereof, and belongs to the field of luminescent functional materials. GeO2, B2O3, ZnO, Na2CO3, Cs2CO3, NaBr, MnBr2, SnO, YbF3 and TmF3 are fully ground to obtain mixed raw materials, which are placed in an air atmosphere at a temperature of 1000-1100 DEG C for high-temperature melting for 10-30 min, poured onto a preheated copper mold, and cooled to form a precursor glass. The precursor glass is sequentially subjected to high-temperature stress relief treatment and high-temperature heat treatment to obtain a non-lead halide perovskite quantum dot microcrystalline glass containing a Cs3MnBr5 nanocrystal phase or containing a Cs3MnBr5 and NaYbF4 nanocrystal double phase. The non-lead halide perovskite quantum dot microcrystalline glass has down-conversion or up-conversion and down-conversion dual-mode luminescence performance, that is, green and red down-conversion luminescence can be realized under excitation of a 365 nm ultraviolet lamp, and blue light and red light high-efficiency up-conversion luminescence can be realized under excitation of 980 nm near-infrared light. The non-lead halide perovskite quantum dot microcrystalline glass has simple preparation process and good luminescence performance, and can be used as a fluorescent anti-counterfeiting material.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of luminescent functional materials, in particular to a non-lead perovskite glass-ceramic material and a preparation method and application thereof BACKGROUND

[0002] In recent years, semiconductor fluorescent nanomaterials have attracted much attention in the field of optoelectronics. Among them, all-inorganic lead-based halide perovskite quantum dots have narrow-band emission, tunable emission wavelength, high color purity, high fluorescence quantum yield, and wide color gamut coverage. However, their stability is too poor, and they are even destroyed when exposed to air, which greatly limits their practical application. In addition, the lead-based halide perovskite quantum dots contain soluble heavy metal Pb, which has potential harm to the ecological environment and human health. Therefore, exploring non-lead metal halide luminescent materials with comparable optoelectronic properties to lead-based halide perovskite but more environmentally friendly has become a new research hotspot.

[0003] Due to the difference in ionic radius between non-lead elements and Pb, replacing Pb with non-lead elements will cause the standard octahedral perovskite structure to deform and dislocate, resulting in the formation of a perovskite-like structure. Such materials are often referred to as non-lead metal halide perovskite materials. Due to the advantages of low toxicity and high abundance of manganese (II) ions, and the large Stokes shift and long excited state lifetime of manganese (II) ion d-d transition, in recent years, manganese (II) based perovskite-like materials prepared by replacing lead ions with manganese (II) ions have shown excellent luminescent properties. SUMMARY

[0004] The purpose of the present application is to provide a non-lead perovskite glass-ceramic material and a preparation method and application thereof. The non-lead perovskite glass-ceramic material can realize upconversion and downconversion dual-mode luminescence performance under 980 nm near-infrared light and 365 nm ultraviolet light excitation, and can be used for fluorescent anti-counterfeiting.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A non-lead perovskite glass-ceramic material obtained by heat treatment of a precursor glass matrix, the component content of the precursor glass matrix being as follows: 30-50 mol% GeO2, 10-40 mol% B2O3, 3-10 mol% ZnO, 3-10 mol% Na2O, 3-10 mol% Cs2O, 5-10 mol% NaBr, 3-10 mol% MnBr2, 0-0.5 mol% SnO, 0-10 mol% YbF3, 0-1 mol% TmF3, the total molar amount of the above components being 100 mol%.

[0007] Further, the precursor glass matrix has the following component content: 35-45 mol% GeO2, 30-40 mol% B2O3, 4-8 mol% ZnO, 4-10 mol% Na2O, 4-10 mol% Cs2O, 4-10 mol% NaBr, 4-8 mol% MnBr2, 0.3-0.5 mol% SnO, 0-8 mol% YbF3, and 0-0.5 mol% TmF3.

[0008] Preferably, the precursor glass matrix has the following component content: 35-45 mol% GeO2, 30-40 mol% B2O3, 4-8 mol% ZnO, 4-10 mol% Na2O, 4-10 mol% Cs2O, 4-10 mol% NaBr, 4-8 mol% MnBr2, 0.3-0.5 mol% SnO, 2.5-8 mol% YbF3, and 0.1-0.5 mol% TmF3.

[0009] The method for preparing the non-lead perovskite glass-ceramic material comprises the following steps:

[0010] (1) GeO2, B2O3, ZnO, Na2CO3, Cs2CO3, NaBr, MnBr2, SnO, YbF3, and TmF3 are weighed according to the molar content of the precursor glass matrix raw materials, and then the raw materials are mixed and ground in an agate mortar to obtain a mixed powder;

[0011] (2) The mixed powder is placed in an alumina crucible and heated and held for a period of time to melt, and the molten liquid is quickly poured into a preheated copper mold to cool and form a precursor glass (PG);

[0012] (3) The precursor glass is subjected to high-temperature stress relief treatment and high-temperature heat treatment to obtain a non-lead perovskite glass-ceramic material containing Cs3MnBr5 nanocrystals or containing Cs3MnBr5 and NaYbF4 nanocrystal double phases.

[0013] In step (2), the holding temperature is 1000-1100°C, preferably 1000-1050°C, and the holding time is 10-30 min, preferably 20-25 min.

[0014] In step (3), the temperature for high-temperature stress relief treatment is 300-350°C, and the stress relief treatment time is 3-5 h.

[0015] In step (3), the heat treatment temperature is 480-540°C, and the heat treatment time is 5-20 h, preferably 10-15 h.

[0016] The non-lead perovskite microcrystalline glass material can be applied in fluorescent anti-counterfeiting materials.

[0017] The application adopts the above technical scheme, and is a method for in-situ precipitation of manganese (II) based perovskite nanocrystals in a glass matrix, and a non-lead perovskite microcrystalline glass material containing a Cs3MnBr5 nanocrystal phase or a dual-phase material containing Cs3MnBr5 and NaYbF4 nanocrystals is prepared. Since the glass has a dense network structure, the physical / chemical stability of the perovskite nanocrystals can be significantly improved by wrapping the perovskite nanocrystals in inorganic amorphous glass, and the stability bottleneck problem of the perovskite material is better solved. The non-lead perovskite quantum dot microcrystalline glass has down-conversion or up-conversion and down-conversion dual-mode luminescence performance, that is, green and red down-conversion luminescence can be realized under the excitation of a 365 nm ultraviolet lamp, and blue light and red light can be efficiently up-converted under the excitation of 980 nm near-infrared light.

[0018] The preparation method is simple, and the obtained microcrystalline glass material has good transparency, and the glass matrix contains uniformly distributed Cs3MnBr5 nanocrystals or a dual-phase material containing Cs3MnBr5 and NaYbF4 nanocrystals. The material integrates down-conversion or up-conversion and down-conversion dual-mode fluorescence emission, and can be used in the field of fluorescent anti-counterfeiting, and is expected to provide more complex, precise and high-level anti-counterfeiting technology. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a physical photo of the microcrystalline glass of Example 1 (from left to right, the precursor glass, the luminescence diagram of the precursor glass under ultraviolet lamp excitation, the microcrystalline glass and the luminescence diagram of the microcrystalline glass under ultraviolet excitation, respectively).

[0020] Figure 2 is the X-ray diffraction spectrum of the microcrystalline glass of Example 1.

[0021] Figure 3 is the emission spectrum of the microcrystalline glass of Example 1 and Example 2 under 365 nm ultraviolet excitation.

[0022] Figure 4 is the X-ray diffraction spectrum of the microcrystalline glass of Example 2.

[0023] Figure 5 is a physical photo of the microcrystalline glass of Example 2 at different heat treatment times (from left to right, the precursor glass, the luminescence diagram of the precursor glass under ultraviolet lamp excitation, the microcrystalline glass and the luminescence diagram of the microcrystalline glass under ultraviolet excitation, respectively).

[0024] Figure 6 is the emission spectrum of the microcrystalline glass of Example 2 under 365 nm ultraviolet excitation corresponding to heat treatment at 540 DEG C for 5-20 h.

[0025] Figure 7is the physical photos of the glass-ceramics of Example 3 (from left to right, the precursor glass, the luminescence photo of the precursor glass under UV light, the glass-ceramics and the luminescence photo of the glass-ceramics under UV excitation, respectively).

[0026] Figure 8 is the emission spectrum of the samples S1, S2, S3 in Example 3 under 365 nm UV excitation.

[0027] Figure 9 is the physical photos of the glass-ceramics of Example 4 (from left to right, the precursor glass, the luminescence photo of the precursor glass under UV light, the glass-ceramics and the luminescence photo of the glass-ceramics under UV excitation, respectively).

[0028] Figure 10 is the X-ray diffraction pattern of the glass-ceramics of Example 4.

[0029] Figure 11 is the emission spectrum of the glass-ceramics of Example 4 under 365 nm UV excitation.

[0030] Figure 12 is the upconversion spectrum of the glass-ceramics of Example 4 under 980 nm near-infrared light excitation.

[0031] Figure 13 is the luminescence photo of the anti-counterfeiting pattern of the glass-ceramics of Example 4 under different excitation modes (from left to right, the natural light, the UV light excitation and the near-infrared laser excitation, respectively).

[0032] Figure 14 is the X-ray diffraction pattern of the glass-ceramics of Example 5.

[0033] Figure 15 is the upconversion spectrum of the glass-ceramics of Example 5 under 980 nm near-infrared light excitation. DETAILED DESCRIPTION

[0034] The application will be further described in conjunction with the specific embodiments, but the protection scope of the application is not limited to the described content.

[0035] Example 1

[0036] The molar ratios of GeO2, B2O3, ZnO, Na2CO3, Cs2CO3, NaBr, and MnBr2 were weighed as follows: GeO2:32.6, B2O3:4.6, ZnO:4.6, Na2O:7, Cs2O:9.4, NaBr:4.6, and MnBr2. The mixture was then thoroughly ground in an agate mortar and placed in a crucible, which was then heated to 1050℃ in a high-temperature box furnace and held for 30 minutes to melt the mixture. The molten liquid was then rapidly poured into a copper mold to cool and solidify, resulting in a bulk brownish-red precursor glass that glows red under ultraviolet light. The precursor glass was annealed at 300℃ and then heat-treated at 520℃ for 10 hours to obtain a Cs3MnBr5-containing microcrystalline glass, which glows orange under ultraviolet light (e.g., ...). Figure 1 ).

[0037] X-ray diffraction data indicate that the Cs3MnBr5 crystalline phase (e.g., ...) was successfully precipitated in the glass matrix. Figure 2 The room-temperature emission spectrum was measured using a fluorescence spectroscopy instrument. The emission spectra showed that the glass-ceramic exhibited two emission peaks under 365 nm ultraviolet light excitation, with peak values ​​at 526 nm and 678 nm, and full width at half maximum (FWHM) of 48 nm and 138 nm, respectively. These peaks correspond to the Mn content in the Cs3MnBr5 nanocrystals and the glass matrix. 2+ The emission peaks of the two luminescent centers, such as Figure 3 As shown.

[0038] Example 2

[0039] The molar ratios of GeO2, B2O3, ZnO, Na2CO3, Cs2CO3, NaBr, MnBr2, and SnO were 37.0:32.3 (GeO2:32.3, B2O3:4.6, ZnO:4.6, Na2O:7, Cs2O:9.4, NaBr:4.6, MnBr2:0.5). These were weighed, mixed thoroughly in an agate mortar, and then placed in a crucible. The crucible was then heated to 1000℃ in a high-temperature box furnace and held for 20 minutes to melt the mixture. The molten liquid was then rapidly poured into a copper mold and cooled to form a transparent bulk precursor glass. The XRD pattern of the precursor glass showed a large amorphous bump, indicating the absence of a crystalline phase. The precursor glass was annealed at 310℃ and then heated to 540℃, held for 5–20 hours, to obtain a transparent microcrystalline glass containing the Cs3MnBr5 crystalline phase. The X-ray diffraction pattern is shown below. Figure 4 As shown in the figure, Cs3MnBr5 nanocrystals precipitated in the heat-treated sample. Compared with Example 1, the sample of Example 2 is transparent. Figure 5), the precursor glass emits red light under UV lamp irradiation, and the sample after heat treatment emits orange-yellow light under UV lamp irradiation. Due to the introduction of SnO in the component, a reducing environment is generated, maintaining the divalent state of manganese ions. Compared with Example 1, the luminescence intensity of the sample of Example 2 is stronger Figure 3 ), indicating that the Cs3MnBr5 crystal phase is better precipitated in the glass matrix. Under UV light 365 nm excitation, only the emission peak at 678 nm is observed for the precursor glass, and two emission peaks are observed for the sample after heat treatment under UV light 365 nm excitation, with peak values at 524 nm and 678 nm, corresponding to Cs3MnBr5 nanocrystals and Mn 2+ Two luminescence center emission peaks, with the increase of heat treatment time, the luminescence intensity first increases and then decreases, as shown in Figure 6 .

[0040] Example 3

[0041] On the basis of Example 2, the content of stannous oxide in the component is changed, and the raw material components are shown in Table 1. The sample real object luminescence is compared, the precursor glass emits red light under UV lamp irradiation, and the sample after heat treatment emits orange-yellow light under UV lamp irradiation, with slight changes in luminescence intensity. As shown in Figure 8 , the sample is heat treated at 540°C for 10h, and two emission peaks are observed under UV light 365 nm excitation, with peak values at 524 nm and 678 nm, corresponding to Cs3MnBr5 nanocrystals and Mn 2+ Two luminescence center emission peaks, with the increase of heat treatment time, the luminescence intensity first increases and then decreases, as shown in

[0042] Table 1 Sample S1-S3 raw material component table with different stannous oxide contents

[0043]

[0044] Example 4

[0045] GeO2, B2O3, ZnO, Na2CO3, Cs2CO3, NaBr, MnBr2, SnO and YbF3, TmF3 were weighed according to the molar ratio of 35GeO2:30B2O3:4.5ZnO:4.5Na2O:6.6Cs2O:8.8NaBr:4.5MnBr2:0.5Sn:5.5YbF3:0.1TmF3, mixed and ground uniformly in an agate mortar, and then placed in a crucible, and then put into a high temperature box furnace and heated to 1000℃, and kept for 20min to make it melt; then the molten liquid was quickly poured into a copper mold tool to cool and form a transparent bulk precursor glass, which emits light in light yellow green under the irradiation of ultraviolet lamp; finally, the precursor glass was annealed at 320℃, and then heated to 540℃, and kept for 10 hours to obtain a Cs3MnBr5 and NaYbF4 nanocrystal dual-phase transparent microcrystalline glass which emits light in yellow green under the irradiation of ultraviolet lamp, as shown in Figure 9 . The room temperature emission spectrum was measured by a fluorescence spectrometer, and the luminescence spectrum results show that the microcrystalline glass has three emission peaks under the excitation of ultraviolet light 365nm, and the emission peak values are respectively 450nm, 525nm and 650nm, corresponding to the transitions of Tm 3+ ions 1 D2→ 3 F4, and the emission peaks of Cs3MnBr5 nanocrystals and Mn 2+ two luminescence centers in the glass matrix; in this embodiment, fluoride is introduced into the components, and fluoride ions can break the dense glass network structure, so that the Cs3MnBr5 nanocrystals can grow more easily in the glass matrix, and compared with the microcrystalline glasses of embodiments 2 and 3, the emission intensity at 525nm of the microcrystalline glass is higher than that at 650nm ( Figure 11 ). The upconversion fluorescence spectrum of the microcrystalline glass was tested under the excitation of 980nm, as shown in Figure 12 . It can be observed from the figure that the upconversion fluorescence spectrum presents three typical upconversion emission zones of Tm 3+ ions: the peak value of the strong ultraviolet light at 363nm corresponds to the energy level transition of 1 D2→ 3 H6; the peak values of the strong blue light at 450nm and 477nm correspond to the energy level transitions of 1 D2→ 3 F4 and 1 G4→ 3 H6; the peak values of the red light at 650nm and 701nm correspond to the energy level transitions of 1 G4→ 3 F4 and 2 F 2,3 → 3H6 energy level transition. It is worth noting that in the upconversion spectrum of this dual crystalline phase glass, in addition to the three typical upconversion emission regions of Tm 3+ ion, a fluorescence emission at 513 nm was additionally found, which is generated by the energy transfer from Tm 3+ to Cs3MnBr5 nanocrystals. Using a screen printing technique, several luminescent identification patterns were made using commercial ink and the mixed powder of this dual crystalline phase glass. When the patterns were irradiated by near-infrared laser and ultraviolet lamp, it can be seen that different excitation light shows different luminescent pattern characteristics (green fluorescence under ultraviolet lamp irradiation and blue fluorescence in some areas of the pattern under infrared laser pen irradiation), which realizes unique anti-counterfeiting applications. Figure 13

[0046] Example 5

[0047] On the basis of Example 4, the content of rare earth fluoride YbF3 was changed to control the precipitation of nanocrystals in the glass matrix, and the components are shown in Table 2.

[0048] Table 2 Sample S1-S5 raw material component table with different rare earth ytterbium fluoride contents

[0049]

[0050] According to the proportioning of the components in Table 2, the components were weighed, mixed and ground uniformly in an agate mortar, and then placed in a crucible, and then placed in a high-temperature box furnace and heated to 1000℃ and kept for 20 min to melt; then the molten liquid was quickly poured into a copper mold tool to cool and form a transparent bulk precursor glass; finally, the precursor glass was annealed at 320℃ and then heated to 540℃ and kept for 10 hours to obtain S1-S5 microcrystalline glass. The X-ray diffraction pattern is shown in Figure 14 From the figure, it can be seen that only Cs3MnBr5 nanocrystals are precipitated in the samples of S1 and S2 after heat treatment; when the YbF3 doping content is further increased, Cs3MnBr5 and NaYbF4 nanocrystals are precipitated in the glass matrix, and the diffraction peak is enhanced with the increase of the doping content. The upconversion fluorescence spectrum of S1-S5 microcrystalline glass was tested by 980 nm near-infrared light excitation, and it can be seen that no upconversion fluorescence emission band is observed for S1-S2, and when the YbF3 doping content is further increased, the upconversion fluorescence spectrum of samples S3-S5 shows three typical upconversion emission regions of Tm 3+ ion and fluorescence emission at 513 nm generated by energy transfer from Tm 3+ to Cs3MnBr5 nanocrystals in Tm:NaYbF4 nanocrystals, and the emission intensity is enhanced with the increase of YbF3 doping content, as shown in Figure 15 .​

Claims

1. A lead-free perovskite microcrystalline glass material, obtained by heat treatment of a precursor glass matrix, characterized in that, The composition of the precursor glass matrix is ​​as follows: 35~45 mol% GeO2, 30~40 mol% B2O3, 4~8 mol% ZnO, 4~10 mol% Na2O, 4~10 mol% Cs2O, 4~10 mol% NaBr, 4~8 mol% MnBr2, 0.3~0.5 mol% SnO, 2.5~8 mol% YbF3, and 0.1~0.5 mol% TmF3.

2. The method for preparing a lead-free perovskite microcrystalline glass material as described in claim 1, characterized in that, Includes the following steps: (1) Weigh the raw materials GeO2, B2O3, ZnO, Na2CO3, Cs2CO3, NaBr, MnBr2, SnO, YbF3 and TmF3 according to the molar content of the precursor glass matrix components, and then mix and grind the raw materials in an agate mortar to obtain a mixed powder. (2) The mixed powder is placed in an alumina crucible, heated and kept at a certain temperature for a period of time to melt it, and the molten liquid is quickly poured into a preheated copper mold and cooled to form the precursor glass; (3) The precursor glass is subjected to high-temperature stress relief treatment and high-temperature heat treatment to obtain a non-lead perovskite microcrystalline glass material containing Cs3MnBr5 nanocrystals or containing a dual phase of Cs3MnBr5 and NaYbF4 nanocrystals.

3. The method for preparing a lead-free perovskite microcrystalline glass material according to claim 2, characterized in that, In step (2), the heat preservation temperature is 1000~1100 ℃ and the heat preservation time is 10~30 min.

4. The method for preparing a lead-free perovskite microcrystalline glass material according to claim 2, characterized in that, In step (3), the temperature for high-temperature stress relief treatment is 300~350℃, and the time for high-temperature stress relief treatment is 3~5 h.

5. The method for preparing a lead-free perovskite microcrystalline glass material according to claim 2, characterized in that, In step (3), the heat treatment temperature is 480~540 ℃ and the heat treatment time is 5~20 h.

6. The method for preparing a lead-free perovskite microcrystalline glass material according to claim 5, characterized in that, In step (3), the heat treatment time is 10~15 h.

7. The application of the lead-free perovskite microcrystalline glass material as described in claim 1 in the preparation of fluorescent anti-counterfeiting materials.

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