X-ray irradiation induced discoloration Cs4PbBr6 quantum dot glass as well as preparation method and application thereof

Abstract

The invention relates to the technical field of optical glass, in particular to X-ray irradiation induced discoloration Cs4PbBr6 quantum dot glass as well as a preparation method and application thereof, the glass is discolored through X-ray irradiation, and the glass regulates and controls luminescence of quantum dots based on photochromism. The catalyst comprises the following components in percentage by mole: 30-40% of NaH2PO4; 30 to 40 percent of B2O3; 3%-6% of BaF2; 1% to 3% of Sb2O3; 7 to 9 percent of Cs2CO3; 4 to 6 percent of PbBr2; and 10 to 12 percent of NaBr. The X-ray irradiation induced photochromic glass provided by the invention has a compact network structure, is endowed with stable and excellent quantum dot luminescence performance, has relatively high mechanical strength and transparency, and can effectively regulate and control luminescence of perovskite quantum dots through photochromism. The application of the optical glass in the fields of information storage, X-ray detection, aviation, military and the like is expected to be widened. The process is simple, the production cost is relatively low, and the photochromic glass with high optical quality is easy to prepare and obtain.

Description

Technical Field

[0001] The present invention relates to the technical field of optical glass, and in particular to a Cs 4 PbB 6 Quantum dot glass and its preparation method and application. Background Art

[0002] Luminescent materials are used in various fields of daily life. Perovskite quantum dot materials are currently a hot topic among luminescent materials. They have excellent optoelectronic properties such as full spectrum tunability, narrow-band emission peaks, and high luminescence quantum yields. However, their stability has always been a key issue that cannot be ignored. By embedding perovskite quantum dots in the dense network structure of glass, they can be coated, thereby effectively preventing interference from environmental factors and improving stability.

[0003] In the current information society, the development of information storage technology is particularly important. Optical storage technology preserves information for a long time, and information reading and storage are efficient and fast. However, new optical storage technologies are still limited by expensive equipment and complex operations. Photochromism refers to the color change of materials under light stimulation, which is a very promising optical storage technology. In current photochromic materials, information is mainly recorded on the surface of two-dimensional photochromic storage media, such as ceramics and thin films, which makes it difficult to achieve high storage capacity. Glass is a widely used material. Its "short-range order and long-range disorder" glass network structure gives it excellent stability and good transparency. Compared with 2D storage media, high information storage capacity can be achieved in photochromic glass by expanding it into transparent 3D bodies. In addition, the irradiation source X-ray has a short wavelength (0.01-10nm) and high energy. Using rays as the information writing source is expected to break through the grating diffraction limit of traditional visible light and achieve high-precision information storage. Information readout is the key to optical storage. The regulation of quantum dot luminescence based on color change is conducive to lossless information readout. In addition, since the rays are in the ultra-short wavelength range and cannot be seen by the naked eye, it is extremely important to research new detection technologies in order to prevent life safety caused by radiation leakage.

[0004] Therefore, the present invention prepares a new type of X-ray irradiation color-changing Cs 4 PbB 6 Quantum dot glass changes color when exposed to radiation, thereby writing information. The information written can be recorded on the Cs 4 PbB 6 The quantum dots can be clearly read out under excellent luminescence conditions. At the same time, the material can also realize visual monitoring of radiation doses to further prevent radiation leakage. In addition, using short-wavelength radiation as an information storage source will hopefully break through the grating diffraction limit and increase information storage capacity.

[0005] The existing Chinese patent CN 117164240A discloses a CsPbBr3 / Cs4PbBr6 quantum dot glass ceramic composite luminescent material and its preparation method and application. The luminescent material includes perovskite quantum dots and lithium disilicate glass ceramics, wherein the concentration of the perovskite quantum dots is 5-70wt%; the chemical formula of the perovskite quantum dots is CsPbBr3@Cs4PbBr6; the molar percentage composition of the luminescent material is as follows: SiO2: 58-70%, Li2O: 20-35%, Al2O3: 1-5%, K2O: 1-5%, P2O5: 1-5%, La2O3: 1-5%, CsBr: 0.4-5.6%, PbBr2: 0.4-5.6%. This technology only describes a Cs 4 PbB 6 The preparation method of quantum dot glass is the first to use X-ray color change, a new and easy-to-control method, to chromatize Cs 4 PbB 6 The luminescence of quantum dot glass can be regulated, further expanding the application of optical information storage and radiation dose monitoring in perovskite quantum dot glass. Summary of the invention

[0006] The present invention aims to provide a kind of X-ray irradiation induced color change Cs 4 PbB 6 The preparation method of quantum dot glass, the color-changing glass induced by X-ray irradiation provided by the present invention has high mechanical strength and transparency, and its dense network structure gives stable color-changing performance, which is expected to broaden the application of perovskite quantum dot optical glass in the fields of information storage, X-ray detection, aviation, military, etc. In addition, the process of the present invention is simple, the production cost is low, and the color-changing glass with high optical quality can be easily prepared.

[0007] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions: using X-rays to induce structural color change in the glass color, using absorption to regulate the luminescence of quantum dots, and the degree of color change of the quantum dot glass can be used to detect whether X-ray leakage occurs. In addition, the use of a mask plate can realize the writing of optical information.

[0008] A Cs2+ induced color change by X-ray irradiation 4 PbB 6 Quantum dot glass, which changes color by X-ray irradiation, includes the following components in molar percentage: NaH 2 PO 4 : 30~40%; B 2 O 3 :30~40%;BaF 2 :3%~6%; Sb 2 O3 :1~3%; Cs 2 CO 3 :7~9%;PbBr 2 : 4~6%; NaBr: 10~12%.

[0009] On the other hand, the present invention provides an X-ray irradiation induced color change Cs 4 PbB 6 The method for preparing quantum dot glass comprises the following steps:

[0010] S1: Take NaH 2 PO 4 , B 2 O 3 , BaF 2 , Sb 2 O 3 , Cs 2 CO 3 、PbBr 2 , NaBr in an agate mortar and grind in air for 8 minutes to ensure that the raw materials are fully mixed;

[0011] S2: The mixed raw materials in S1 are placed in a crucible, placed in a high-temperature box furnace at 1150°C for 20 minutes, and then the glass liquid is poured onto a copper plate preheated to 330°C;

[0012] S3: The glass obtained in S2 was annealed in a muffle furnace at 350°C for 1 hour to remove the residual thermal stress of the glass; and then heat treated in a muffle furnace at 400°C for 6 hours to make Cs 4 PbB 6 Crystallites precipitate in the glass;

[0013] S4: The glass is ground and polished, and then irradiated with different doses of X-rays for different times;

[0014] S5: Quantum dots have high luminescence efficiency, and their luminescence properties were measured.

[0015] Furthermore, the distribution ratio of each group in the raw material is: NaH 2 PO 4 : 30~40%; B 2 O 3 :30~40%;BaF 2 :3%~6%; Sb 2 O 3 :1~3%; Cs 2 CO 3 :7~9%;PbBr 2 : 4~6%; NaBr: 10~12%.

[0016] On the other hand, the present invention provides the use of the above glass in X-ray irradiation-induced discoloration.

[0017] Beneficial effects of the present invention:

[0018] The glass prepared by the present invention exhibits excellent bright green light at 510nm under an excitation wavelength of 390nm, which meets the requirements of Cs 4 PbB 6 The luminescence characteristics of quantum dots. The dense structure of glass effectively protects the quantum dots and increases the stability of quantum luminescence.

[0019] This technology constructs NaH 2 PO 4 -B 2 O 3 -BaF 2 -Sb 2 O 3 The quaternary glass system combines high-temperature melting and step-by-step heat treatment processes to form a phosphate-borate composite network structure with high mechanical strength and chemical inertness. 4 PbB 6 Quantum dots provide rigid encapsulation protection. NaH 2 PO 4 As the main glass former, its PO tetrahedral network forms a short-range ordered rigid skeleton through strong covalent bonds. The Vickers hardness test shows that the glass hardness reaches 5.8GPa (compared to 4.5GPa of traditional soda-lime glass), and the bending strength is increased to 120MPa. 2 O 3 The introduction of [BO 3 ] triangle and [BO 4 ] The mixed coordination state of tetrahedron adjusts the glass viscosity-temperature curve, realizes rapid and uniform flow of the melt, and avoids mechanical defects caused by phase separation. 2 As a mineralizer, it lowers the glass transition temperature and - Br on the surface of quantum dots - The ion exchange forms a passivation layer to inhibit the surface oxidation of quantum dots. 2 O 3 As a reducing agent, it preferentially reacts with O in the melting process 2 Reaction, Pb 2+ The oxidation ratio of Pb is controlled at <1% to avoid 4+ Luminescence quenching caused by impurity phase.

[0020] The prepared glass produces obvious photochromic phenomenon under X-ray irradiation. The degree of color change of quantum dot glass changes with the irradiation dose and time, which explains the application of quantum dot glass in the visual detection of X-ray leakage. This invention is the first to use high atomic number metal oxide (BaF2 ) and color center forming auxiliary agent (Sb 2 O 3 ) is introduced into the glass matrix, and through the separation of electron-hole pairs induced by X-rays, F-type color centers are dynamically formed, achieving a highly sensitive response to radiation dose and visual color change detection. 2+ The high photoelectric absorption cross section of ions significantly improves the absorption efficiency of glass for X-rays, which is higher than that of undoped BaF. 2 40% to 75%. 2 F - Vacancies capture high-energy electrons under irradiation conditions (generating F-type color centers), and the absorption peak formed in the visible light region (at 550nm) greatly enhances the optical density change, presenting a yellow discoloration phenomenon visible to the naked eye. 2 O 3 In this system, Sb plays a decisive role in charge compensation. 3+ It can capture electrons to form Sb 2+ , and can capture holes to form Sb 4+ This bidirectional redox regulation mechanism significantly improves the controllability and efficiency of color center formation. 2 O 3 When the content is in the range of 1%-3%, it can stably achieve a linear relationship between the color change depth (ΔOD) and the dose, with a linearity of 0.998 and a sensitivity of 0.5ΔOD / (Gy / s). Compared with traditional radiochromic materials such as GAF Chromic film, its sensitivity in the low-dose response range (0.002-0.01Gy / s) has been more than doubled. Kinetic tests show that after continuous irradiation for 21 minutes at a dose of 0.00751Gy / s, ΔOD steadily increases to 1.2, and the dynamic response rate remains constant as the dose changes. This feature provides technical support for the realization of real-time radiation dose monitoring, and is particularly suitable for radiation environment safety assessment in the nuclear industry and medical fields.

[0021] The photochromic effect is used to regulate the luminescence of quantum dots. Since quantum dots have high luminescence efficiency, the information written in the glass through the color-changing process can be effectively read under excellent luminescence conditions, further expanding its applications in optical storage, Micro-LED, etc.

[0022] Cs was prepared by high temperature solid phase sintering 4 PbB 6Quantum dot glass, the present invention realizes the combination of simple process, strong controllability and excellent material performance. The raw materials are melted at a high temperature of 1150℃ to form a uniform glass liquid, and the internal stress is eliminated after rapid cooling to a solid state, ensuring the structural integrity and transparency of the glass. The chemical stability of the glass comes from the strength of the phosphorus-oxygen bond in its glass network. This "short-range order, long-range disorder" structural characteristic not only ensures the thermal and chemical stability of the glass, but also provides sufficient optical transparency.

[0023] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0025] Figure 1 is the test result of the glass of the present invention under X-ray diffractometer (XRD), wherein the peak position basically corresponds to Cs 4 PbB 6 The standard PDF card shows that the microcrystals precipitated from the glass belong to Cs 4 PbB 6 The standard phase of

[0026] Figure 2 These are photos of the glass of the present invention irradiated with X-rays at a dose of 0.00751 Gy / s for different time periods. The glass is yellow and transparent in the initial state, and the color deepens as the irradiation time increases; (a) 3 min; (b) 9 min; (c) 15 min; (d) 21 min;

[0027] Figure 3 These are photos of the glass of the present invention after being irradiated with different doses of X-rays for 15 minutes. It can be seen that as the dose increases, the color of the glass deepens; (a) initial state; (b) 0.00249 Gy / s; (c) 0.00557 Gy / s; (d) 0.00751 Gy / s;

[0028] Figure 4 It is the transmission spectrum of the glass of the present invention before and after the color change due to X-ray irradiation. The transmittance of the glass after X-ray irradiation in the 500-600nm band is significantly reduced, indicating that the color change is deepened;

[0029] Figure 5The emission spectrum of the glass of the present invention before and after X-ray irradiation and discoloration, the emission peak wavelength is around 510nm. The luminescence intensity of the glass is significantly reduced after X-ray irradiation, indicating that photochromism effectively regulates the luminescence of quantum dots;

[0030] Figure 6 This is a simple application of the glass of the present invention in optical storage. Information can be written into the glass using a mask and read out under luminous conditions; (a) natural light; (b) 365nm light excitation. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] The X-ray irradiation-induced color change Cs 4 PbB 6 The method for preparing quantum dot glass and the degree of discoloration of the glass at different times of X-ray irradiation comprise the following steps:

[0034] S1: Weigh 15g of raw materials according to the following composition: NaH 2 PO 4 : 36%; B 2 O 3 : 33%; BaF 2 :6%; Sb 2 O 3 :1%;Cs 2 CO 3 :7%;PbBr 2 : 4%; NaBr: 13%; Mix the raw materials in an agate mortar and grind in air for 10 minutes to ensure that the raw materials are fully mixed.

[0035] S2: The mixed raw materials in S1 are loaded into a crucible, and placed in a high-temperature box furnace at 1150°C for 20 minutes. The glass liquid is then poured onto a copper plate preheated to 330°C, and cooled to room temperature along with the heating furnace.

[0036] S3: The glass obtained in S2 was annealed in a muffle furnace at 350°C for 1 hour to remove the residual thermal stress of the glass; and then heat treated in a muffle furnace at 400°C for 6 hours to make Cs 4 PbB 6 Crystallites precipitate in the glass;

[0037] S4: Grind and polish the glass.

[0038] S5: Test the XRD pattern of the glass prepared in S4.

[0039] S6: The glass prepared in S4 was irradiated with X-rays for different time periods, 3 min, 9 min, 15 min, and 21 min, with an X-ray dose of 0.00751 Gy / s.

[0040] In this embodiment 1, the glass was tested by an X-ray diffractometer to determine the composition of the crystallites precipitated in the glass, such as Figure 1 As shown. The glass is irradiated with the same dose of X-rays for different time periods, as shown Figure 2 As shown in (ad), the glass turns brown after X-ray irradiation. The transparent yellow glass changes color more with the increase of X-ray irradiation time, showing a significant degree of color change, indicating that X-ray induced color-changing glass has excellent X-ray detection capability.

[0041] Example 2

[0042] The X-ray irradiation-induced color change Cs 4 PbB 6 The preparation method of quantum dot glass, the influence of X-ray irradiation dose on the discoloration degree of glass, and the regulation process of photochromic effect on the luminescence of quantum dots include the following steps:

[0043] S1: Weigh 15g of raw materials according to the following composition: NaH 2 PO 4 :36%; B 2 O 3 : 33%; BaF 2 :6%; Sb 2 O 3 :1%;Cs 2 CO 3 :7%;PbBr 2 : 4%; NaBr: 13%; Mix the raw materials in an agate mortar and grind in air for 10 minutes to ensure that the raw materials are fully mixed.

[0044] S2: The mixed raw materials in S1 are loaded into a crucible, and placed in a high-temperature box furnace at 1150°C for 20 minutes. The glass liquid is then poured onto a copper plate preheated to 330°C, and cooled to room temperature along with the heating furnace.

[0045] S3: The glass obtained in S2 was annealed in a muffle furnace at 350°C for 1 hour to remove the residual thermal stress of the glass; and then heat treated in a muffle furnace at 400°C for 6 hours to make Cs 4 PbB 6 Crystallites precipitate in the glass;

[0046] S4: Grind and polish the glass.

[0047] S5: Determine the X-ray irradiation time to be 15 minutes, and change different X-ray irradiation doses.

[0048] S6: The transmission spectrum and emission spectrum of the glass prepared in S4 are tested before and after discoloration by X-ray irradiation.

[0049] In this embodiment 2, the X-ray irradiation time is determined and the irradiation dose is changed, such as Figure 3 As shown in (ad), the transparent glass changes color more with the increase of irradiation dose, indicating that the glass is responsive to the X-ray irradiation dose, and further indicating that the glass prepared by the present invention can realize X-ray detection and optical information storage by using a mask. Then the transmission spectrum of the glass before and after the color change was tested, as shown in FIG. Figure 4 As shown in the figure, the transmittance of the glass decreases after the color change, indicating the excellent color change performance of the glass under X-ray irradiation. The emission spectrum before and after the color change was also tested, as shown in the figure. Figure 5 As shown, the luminescence intensity of the glass decreases with photochromism, which explains the regulatory effect of photochromism on the luminescence of quantum dots.

[0050] Example 3

[0051] The X-ray irradiation-induced color change Cs 4 PbB 6 A method for preparing quantum dot glass, which exhibits excellent X-ray irradiation color change performance, which is reflected in practical applications, comprises the following steps:

[0052] S1: Weigh 15g of raw materials according to the following composition: NaH 2 PO 4 :36%; B 2 O 3 : 33%; BaF 2 :6%; Sb 2 O 3 :1%;Cs 2 CO 3 :7%;PbBr 2 : 4%; NaBr: 13%; Mix the raw materials in an agate mortar and grind in air for 10 minutes to ensure that the raw materials are fully mixed.

[0053] S2: The mixed raw materials in S1 are loaded into a crucible, and placed in a high-temperature box furnace at 1150°C for 20 minutes. The glass liquid is then poured onto a copper plate preheated to 330°C, and cooled to room temperature along with the heating furnace.

[0054] S3: The glass obtained in S2 was annealed in a muffle furnace at 350°C for 1 hour to remove the residual thermal stress of the glass; and then heat treated in a muffle furnace at 400°C for 6 hours to make Cs 4 PbB 6 Crystallites precipitate in the glass;

[0055] S4: Grind and polish the glass.

[0056] S5: Place the mask with the hollow pattern between the radiation and the glass. After 20 minutes of radiation irradiation, obvious pattern information can be written in the glass. Under the illumination of a 365nm flashlight, the written pattern can also be clearly read under the light of the glass.

[0057] This embodiment 3 shows the simple application of the invention. Figure 6 As shown in (a, b), the transparent yellow glass is written with the pattern information on the mask under the irradiation of the radiation, which is clearly visible under natural light. At the same time, it is more obvious under the luminous condition. 4 PbB 6 Quantum dot glass promotes its application in fields such as optical information storage.

[0058] The present invention uses the viscous flow characteristics of borate glass to slowly diffuse Cs, Pb, and Br ions in a quasi-solid environment through low-temperature and long-term heat treatment (400°C for 6 hours), and controls the size of quantum dots to 5±0.8 nanometers through Ostwald ripening. This temperature is just close to the transition temperature of glass (DSC measured Tg=350°C). During annealing, the glass network can be partially relaxed to make room for the growth of quantum dots, but it will not completely soften and cause structural collapse. Conventional practice is to anneal at 50°C below Tg, and quantum dots cannot be generated; and if it exceeds Tg+100°C, the glass will deform as a whole. The setting point of 400°C in the present invention is the balance point between the uniformity of quantum dot size and the stability of the glass matrix.

[0059] At present, there is no material on the market that can be used as a radiation dosimeter, optical storage medium, and LED color conversion layer at the same time. The present invention can realize the use of X-rays to write an invisible QR code on glass. It is usually invisible to the naked eye, but when it is illuminated by ultraviolet light, the quantum dot luminescent area and the irradiated color change area will form a light and dark contrast, and the information can be read by directly scanning the code. The realization of this multimodal information storage relies on the spectral separation design of quantum dot luminescence and color center absorption. The emission peak of the quantum dot is at 510nm, and the absorption peak of the color center is at 550nm. The overlap area between the two is less than 5%, so the luminescent signal will not be interfered by the color center, solving the pain point of read-write crosstalk of traditional photochromic materials.

[0060] Transparent X-ray irradiation-induced color-changing Cs 4 PbB 6Quantum dot glass, in which the sintering temperature is 1150℃ and the time is 20 minutes, shows different degrees of color change under different X-ray doses and irradiation times, and can be put into practical use. The X-ray irradiation color-changing quantum dot glass, due to its excellent X-ray response ability, shows great application prospects in information storage, X-ray dosimeters, aviation, military and other fields.

[0061] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A Cs4PbBr6 quantum dot glass induced by X-ray irradiation, characterized in that: The color changes are produced by X-ray irradiation, and the Cs4PbBr6 quantum dot glass regulates the luminescence of quantum dots based on photochromism; Its components, measured by molar percentage, include: NaH2PO4: 30-40%; B2O3: 30-40%; BaF2: 3%-6%; Sb2O3: 1-3%; Cs2CO3: 7-9%; PbBr2: 4-6%; and NaBr: 10-12%.

2. The method for preparing Cs4PbBr6 quantum dot glass according to claim 1, characterized in that: The following steps are involved: S1: Mix NaH2PO4, B2O3, BaF2, Sb2O3, Cs2CO3, PbBr2 and NaBr in an agate mortar and grind in air for 8 minutes to make the raw materials fully mixed; S2: The mixed raw materials in S1 are placed in a crucible, placed in a high-temperature box furnace at 1150°C for 20 minutes, and then the glass liquid is poured onto a copper plate preheated to 330°C; S3: annealing the glass obtained in S2 in a muffle furnace at 350°C for 1 hour to remove the residual thermal stress of the glass; and then heat treating in a muffle furnace at 400°C for 6 hours to precipitate Cs4PbBr6 microcrystals in the glass; S4: The glass is ground and polished, and then irradiated with different doses of X-rays for different times; S5: Quantum dots have high luminescence efficiency, and their luminescence properties were measured.

3. The preparation method according to claim 2, characterized in that: The distribution ratio of each group in the raw material is: NaH2PO4: 30-40%; B2O3: 30-40%; BaF2: 3%-6%; Sb2O3: 1-3%; Cs2CO3: 7-9%; PbBr2: 4-6%; NaBr: 10-12%.

4. Application of the Cs4PbBr6 quantum dot glass as described in claim 1 in X-ray irradiation-induced color change and regulation of quantum dot luminescence.

Images