Preparation method of double perovskite photochromic fluorescent powder and reversible light emission regulation

Abstract

This invention relates to the field of photochromic phosphors, specifically to a method for preparing a double perovskite photochromic phosphor and its reversible luminescence regulation. The invention involves grinding and mixing high-purity BaCO3, La2O3, Nb2O5, Ag2O, Yb2O3, and Er2O3 to obtain a mixed powder A. Mixed powder A is then sintered at 1350℃ in air for 6 hours, and further ground to obtain Ba2LaNbO6:Yb 3+ Er 3+ Ag + Photochromic phosphor; this phosphor can rapidly change from white to pink under 365nm ultraviolet light, and can change back from pink to white under 470nm ultraviolet light, with the luminescence intensity of the phosphor also returning to its original intensity. This achieves photochromic regulation of the luminescence intensity of the double perovskite Ba2LaNbO6:Yb 3+ Er 3+ Ag + The luminescent properties of the double perovskite phosphor of this invention are excellent under ultraviolet excitation and 980nm laser excitation, exhibiting reversible photochromic and reversible luminescence modulation properties, and have great application potential in fields such as optical switches and optical storage.

Description

Technical Field

[0001] This invention belongs to the field of photochromic phosphor technology, specifically relating to a method for preparing a double perovskite photochromic phosphor and its reversible luminescence regulation. Technical Background

[0002] Photoluminescent materials have wide applications in lighting, displays, and bioimaging. In particular, lead-free double perovskite halides have attracted considerable research interest in recent years due to their high photoluminescence quantum yield, extremely high light absorption coefficient, large defect tolerance, and ultra-long carrier diffusion length, particularly in lighting, X-ray scintillators, photoelectric sensors, and bioimaging. Furthermore, the application range of lead-free double perovskite halide photoluminescent materials can be expanded by modulating luminescence using external fields (such as light, electric, and magnetic fields), for applications like temperature sensing and anti-counterfeiting. Among these, light field manipulation is favored by many researchers due to its safety, ease of operation, and reversibility.

[0003] Photochromism is the ability to produce a significant color change under light induction. Photochromism allows for reversible control of luminescence, thus promoting the application of luminescent materials in optical storage and anti-counterfeiting. However, the poor stability of lead-free bis-perovskite halides limits their application in complex environments. Compared to lead-free bis-perovskite halides, lead-free bis-perovskite oxides offer better stability and matrix selectivity, making them promising candidates for photochromic materials.

[0004] This invention develops a method for preparing a double perovskite photochromic phosphor and its reversible luminescence modulation. Under stimulation by a 365nm ultraviolet lamp, it can rapidly change from white to pink, while simultaneously modulating the luminescence through rare earth ions such as Er... 3+ With ion doping, the sample can achieve upconversion photoluminescence modulation under 980nm laser excitation, and the color and luminescence intensity of the sample can be restored to their original state by a 470nm lamp. Through photochromism, the luminescence can be modulated, thereby promoting the application of double perovskite luminescent materials in fields such as optical storage and anti-counterfeiting. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention proposes a method for preparing a double perovskite photochromic phosphor and reversible luminescence modulation. A short period of irradiation with 365nm ultraviolet light produces a white-to-pink color-changing effect, and subsequently, under irradiation with a 470nm lamp, the sample's color reverts from pink back to its original white. Because Er 3+The doping of ions resulted in the sample emitting a distinct green light under 980nm laser stimulation, and the luminescence could be reversibly controlled through a color-changing effect. This multi-functionality of color-changing and luminescence holds promise for advancing the application of double perovskite oxides in fields such as optical switches, information storage, and anti-counterfeiting.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0007] A method for preparing a double perovskite photochromic phosphor and its reversible luminescence modulation, characterized by comprising the following steps:

[0008] S1: Grind and mix high-purity BaCO3, La2O3, Nb2O5, Ag2O, Yb2O3 and Er2O3 to obtain mixed powder A;

[0009] S2: The mixed powder A obtained in S1 was sintered at 1350℃ in air for 6 hours. After naturally cooling to room temperature, it was ground to obtain Ba2LaNbO6:Yb 3+ Er 3+ Ag + Photochromic fluorescent powder;

[0010] Furthermore, in step S1, the raw materials BaCO3, La2O3, and Nb2O5 are weighed in a stoichiometric ratio of 2:1:1, and the dopant ion Ag... + Ag2O, Yb 3+ Yb2O3 and Er 3+ Er₂O₃, calculated as a mol percentage, contains 2 mol%, 10 mol%, and 6 mol%, respectively.

[0011] Furthermore, Ba2LaNbO6:Yb 3+ Er 3+ Ag + The photochromic fluorescent powder changes from white to pink under 365nm ultraviolet light; under 470nm light, it returns to its original white color; and under 980nm laser excitation, it achieves Er... 3+ Reversible luminescence modulation of ions.

[0012] Furthermore, the diffuse reflectance spectra of the phosphor before and after illumination at 365 nm and 470 nm were measured using a spectrophotometer (U-4100) equipped with an integrating sphere, and the emission spectra before and after color change were measured using a fluorescence spectrometer (F7000).

[0013] A method for preparing a double perovskite photochromic phosphor and its reversible luminescence modulation are disclosed. The phosphor exhibits a significant color-changing effect, changing from white to pink, after approximately 8 seconds of irradiation with a 365nm UV lamp. It can be restored to its initial state upon irradiation with a 470nm lamp, demonstrating good reversibility. Upon excitation with 980nm, it exhibits Er... 3+ It exhibits typical emission spectra of ions and allows for reversible control of luminescence.

[0014] Based on the above technical solution, the beneficial effects of the present invention are as follows:

[0015] 1. Through low-valence ions Ag + The doping of phosphors in Ba2LaNbO6 double perovskite oxides resulted in a significant reversible photochromic phenomenon: under 365nm UV light irradiation, the phosphor color could rapidly change from white to pink; under 470nm light irradiation, the sample color could be restored from pink back to the original white.

[0016] 2. Based on the photochromic phenomenon, the photochromic properties of inorganic double perovskite oxides Ba2LaNbO6:Yb were achieved. 3+ Er 3+ Ag + Reversible luminescence modulation: When the sample changes from white to pink, the luminescence intensity of the phosphor decreases accordingly; after bleaching the phosphor with a 470nm lamp, the luminescence intensity of the sample can be restored to its original intensity. Attached Figure Description

[0017] The accompanying drawings are used to illustrate specific embodiments of this experiment and form part of the application, but do not constitute a limitation on the embodiments of the present invention.

[0018] Figure 1 The components are Ba2LaNbO6 and Yb as described in Example 1, respectively. 3+ Er 3+ Ag + Diffuse reflectance and emission spectra of phosphors after irradiation with a 365nm ultraviolet lamp for 0s and 8s, respectively;

[0019] Figure 2 The color-changing Ba2LaNbO6:Yb described in Example 2 are respectively 3+ Er 3+ Ag + Diffuse reflectance and emission spectra of phosphors after irradiation with a 470nm lamp for 0s and 30s, respectively;

[0020] Figure 3 , 4 Ba2LaNbO6:Yb as described in Example 3 3+ Er 3+ Ag +Photos of phosphor before and after 8 seconds of exposure to a 365nm ultraviolet lamp.

[0021] Specific Implementation Cases

[0022] The present invention will be further described below with reference to specific embodiments and accompanying drawings, but the present invention is not limited to the following embodiments.

[0023] A method for preparing a double perovskite photochromic phosphor and its reversible luminescence modulation, characterized by comprising the following steps:

[0024] S1: Grind and mix high-purity BaCO3, La2O3, Nb2O5, Ag2O, Yb2O3 and Er2O3 to obtain mixed powder A;

[0025] S2: The mixed powder A obtained in S1 was sintered at 1350℃ in air atmosphere for 6 hours, and after naturally cooling to room temperature, it was ground to obtain Ba2LaNbO6:Yb 3+ Er 3+ Ag + Photochromic fluorescent powder;

[0026] S3: Raw materials BaCO3, La2O3, and Nb2O5 are weighed in a stoichiometric ratio of 2:1:1, and dopant ions Ag are added. + Ag2O), Yb 3+ Yb2O3) and Er 3+ Er₂O₃, calculated as a mol percentage, contains 2 mol%, 10 mol%, and 6 mol%, respectively.

[0027] S4:Ba2LaNbO6:Yb 3+ Er 3+ Ag + The photochromic fluorescent powder changes from white to pink under 365nm ultraviolet light; under 470nm light, it returns to its original white color; and under 980nm laser excitation, it achieves Er... 3+ Reversible luminescence modulation of ions.

[0028] Example 1

[0029] like Figure 1 As shown, the Ba2LaNbO6:Yb content was measured using a spectrophotometer (U-4100) equipped with an integrating sphere. 3+ Er 3+ Ag + The diffuse reflectance and emission spectra of the phosphor before and after 8 seconds of illumination at 365 nm.

[0030] Ba2LaNbO6:Yb 3+ Er3+ Ag + After irradiating the phosphor with a 365nm UV lamp for 8 seconds, the diffuse reflectance spectra of the samples before and after color change were measured. It can be seen that the diffuse reflectance spectrum of the phosphor after UV-induced color change decreased in the 400nm-800nm ​​range compared to the spectrum before color change, indicating that 365nm can effectively induce the color change of Ba2LaNbO6:Yb. 3+ Er 3+ Ag + The photochromic phenomenon of the phosphor. Simultaneously, the emission spectrum shows that the luminescence intensity of the phosphor decreases after the color change, indicating that the photochromic effect can effectively control the emission of Ba2LaNbO6:Yb. 3+ Er 3+ Ag + Regulation of photoluminescence of phosphors.

[0031] Example 2

[0032] like Figure 2 As shown, the color-changing Ba2LaNbO6:Yb was measured. 3+ Er 3+ Ag + The diffuse reflectance and emission spectra of the phosphor after irradiation with a 470nm lamp for 0s and 30s, respectively.

[0033] Ba2LaNbO6:Yb changes color under 470nm light. 3+ Er 3+ Ag + After 30 seconds of phosphor irradiation, the diffuse reflectance spectrum of the sample returned to its original state, and correspondingly, the intensity of its emission spectrum also returned to the intensity of the uncolored sample, indicating that Ba2LaNbO6:Yb 3+ Er 3+ Ag + The photochromic properties and luminescence modulation of phosphors are reversible.

[0034] Example 3

[0035] like Figure 3 As shown, Ba2LaNbO6:Yb 3+ Er 3+ Ag + Phosphor irradiated with a 365nm UV lamp for 8 seconds, Ba2LaNbO6:Yb 3+ Er 3+ Ag +The phosphor changed from white to pink. A method for preparing a double perovskite photochromic phosphor and its reversible luminescence regulation is expected to achieve significant and rapid response reversible luminescence regulation of double perovskite oxide Ba2LaNbO6 through the photochromic effect, effectively promoting the application prospects of double perovskite oxide in fields such as optical switches, information storage, and anti-counterfeiting.

[0036] The Ba2LaNbO6:Yb obtained in this invention 3+ Er 3+ Ag + Phosphor, wherein the sintering temperature is 1350℃ and the sintering time is 6h, yields a phosphor capable of controlling Er through photochromism. 3+ Ion-luminescent photochromic phosphor Ba2LaNbO6:Yb 3+ Er 3+ Ag + Phosphor. This indicates that rare-earth ion-doped photochromic Ba2LaNb6 phosphor has broad application prospects in optical switches, optical storage, and optical detectors.

[0037] Although the main inventive examples that influence the factors of this experiment have been described and listed, those skilled in the art will understand that various changes, explorations, modifications and combinations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for preparing a double perovskite photochromic phosphor, characterized in that, Includes the following steps: S1: Grind and mix high-purity BaCO3, La2O3, Nb2O5, Ag2O, Yb2O3 and Er2O3 to obtain mixed powder A; S2: The mixed powder A obtained in S1 was sintered at 1350℃ in air for 6 hours. After naturally cooling to room temperature, it was ground to obtain Ba2LaNbO6:Yb 3+ Er 3+ Ag + Photochromic fluorescent powder.

2. The method for preparing a double perovskite photochromic phosphor according to claim 1, characterized in that: The raw materials BaCO3, La2O3, and Nb2O5 were weighed in a stoichiometric ratio of 2:1:1, and the doping ion Ag was added. + Ag2O, Yb 3+ Yb2O3 and Er 3+ The Er₂O₃ content, calculated as a mol percentage, is 2 mol%, 10 mol%, and 6 mol%, respectively.

3. The method for preparing a double perovskite photochromic phosphor according to claim 1, characterized in that, Ba2LaNbO6:Yb 3+ Er 3+ Ag + Photochromic phosphors can change from white to pink in a short time when stimulated by a 365 nm ultraviolet lamp.

4. The method for preparing a double perovskite photochromic phosphor according to claim 1, characterized in that: Ba2LaNbO6:Yb 3+ Er 3+ Ag + The photochromic fluorescent powder changes from white to pink under 365 nm UV light; under 470 nm light, it returns to its original white color; and under 980 nm laser excitation, it achieves Er... 3+ Regulation of ion luminescence.

5. A method for preparing a double perovskite photochromic phosphor according to any one of claims 1-4, characterized in that: Ba2LaNbO6:Yb 3+ Er 3+ Ag + Photochromic phosphors can regulate Er ion luminescence through photochromism. When excited by a 980 nm laser, the luminescence intensity decreases as the sample color changes, thus achieving photochromic modulation. When the color of Ba₂LaNbO₆:Yb changes... 3+ Er 3+ Ag + After being irradiated with a 470 nm lamp, the color of the photochromic fluorescent powder returned to its initial state, and correspondingly, the luminescence intensity of the sample also returned to its original state.

6. A double perovskite photochromic phosphor, characterized in that: It is prepared by any one of the methods in claims 1-4.

7. The application of the double perovskite photochromic phosphor according to claim 6 in the field of photochromic phosphor technology.

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