Quantum dot glass raw material, quantum dot glass, quantum dot optical fiber core, and preparation method

Abstract

The present disclosure relates to the technical field of optics. Disclosed are a quantum dot glass raw material, quantum dot glass, a quantum dot optical fiber core, and a preparation method. The quantum dot glass raw material comprises the following elements in mole percentage: Si: 4.96%-21.05%; B: 3.51%-19.85%; Al: 0%-7.44%; G: 0.29%-3.16%; Pb: 0.03%-0.5%; O: 49.15%-60.31%; N: 1.62%-8.77%; M: 5.28%-18.49%; and X: 0.7%-8.16%. The element G is S, Se or Te, the element N is an alkaline earth metal element, the element M is an alkali metal element, and the element X is a halogen element. The halogen element and the alkali metal element work in conjunction to form an alkali metal halide crystal which is located on the surface of PbG quantum dots, so as to passivate the surface of the PbG quantum dots, thereby improving the light-emitting efficiency of the PbG quantum dots.

Description

Quantum dot glass raw material, quantum dot glass, quantum dot optical fiber core and preparation method

[0001] This application claims priority to Chinese patent application No. 202311548105.6, filed on November 17, 2023, entitled “Quantum dot glass raw materials, quantum dot glass, quantum dot optical fiber core and preparation method,” the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of optics, and in particular to quantum dot glass raw materials, quantum dot glass, quantum dot optical fiber cores, and preparation methods. Background Art

[0003] IV-VI semiconductor quantum dots, such as PbS and PbSe, have the advantages of small band gap energy, large exciton Bohr radius, and fluorescence wavelength that can be adjusted below 3μm and 4.4μm, making them widely used in many fields.

[0004] The preparation methods of quantum dots include chemical synthesis, sol-gel method, melting method, etc. Among them, the melting method grows quantum dots in a glass matrix through a heat treatment process, which not only prevents the agglomeration of quantum dots, but also helps to improve the chemical stability, thermal stability and mechanical stability of quantum dots.

[0005] However, in related technologies, the luminous efficiency of quantum dots is low and their stability needs to be improved.

[0006] Public content

[0007] In one aspect, a quantum dot glass raw material is provided, wherein the quantum dot glass raw material comprises the following elements in molar percentages: Si element: 4.96% to 21.05%; B element: 3.51% to 19.85%; Al element: 0% to 7.44%; G element: 0.29% to 3.16%; Pb element: 0.03% to 0.5%; O element: 49.15% to 60.31%; N element: 1.62% to 8.77%; M element: 5.28% to 18.49%; X element: 0.7% to 8.16%;

[0008] Among them, the G element is sulfur element S, selenium element Se or tellurium element Te; the N element is an alkaline earth metal element; the M element is an alkali metal element; and the X element is a halogen element.

[0009] The quantum dot glass raw material provided in the embodiments of the present disclosure can be used to prepare quantum dot glass containing PbG quantum dots, and the PbG quantum dots can be PbS quantum dots, PbSe quantum dots or PbTe quantum dots.

[0010] The quantum dot glass raw materials provided by the embodiments of the present disclosure can be used to prepare quantum dot glass products. Based on the synergistic effect of the aforementioned elements at specific molar percentages, the prepared quantum dot glass products have at least the following advantages: PbG quantum dots are formed in situ within the glass matrix, which not only facilitates uniform dispersion of the PbG quantum dots but also improves their stability. By adding a certain amount of halogen elements and alkali metal elements to the raw materials, alkali metal halide crystals (MX crystals) can be formed. The MX crystals are present on the surface of the PbG quantum dots, and the two are connected by halogen-lead bonds, thereby passivating the PbG quantum dot surface. This effectively reduces carrier capture by surface defects in the PbG quantum dots and improves the luminescence efficiency of the PbG quantum dots. Furthermore, when the MX crystal content reaches a high level and reaches a target threshold, it can form a shell layer covering at least a portion of the outer surface of the PbG quantum dots. This not only enhances the surface passivation effect of the PbG quantum dots, but also allows the PbG quantum dots to be protected by both the shell layer and the glass matrix, further improving the mechanical, thermal, and chemical stability of the PbG quantum dots. In addition, the alkali metal halide crystals are also beneficial to reducing the melting temperature and viscosity of the glass melt and improving the uniformity of the glass matrix.

[0011] In some possible implementations, the N element is selected from at least one of Sr, Ca, and Ba.

[0012] In some possible implementations, the M element is selected from at least one of Na, K, and Li.

[0013] In some possible implementations, the X element is selected from at least one of Cl, Br, and I.

[0014] Cl, Br, and I are selected as X elements. They are compounded with the alkali metal element M to form alkali metal halide crystals and bind to the outer surface of the PbS quantum dots, thereby passivating the surface defects of the PbS quantum dots and improving the luminous efficiency.

[0015] In some possible implementations, the Si element exists in the form of silicon oxide;

[0016] The B element exists in the form of boron oxide;

[0017] The Al element exists in the form of aluminum oxide;

[0018] The G element is present in at least one of the MG form and the G elemental form;

[0019] The Pb element is present in at least one of the form of lead oxide and the form of single lead;

[0020] The alkaline earth metal element N is present in at least one of the form of an alkaline earth metal carbonate compound and an alkaline earth metal halide;

[0021] The alkali metal element M is present in at least one of the form of an alkali metal carbonate compound, an alkali metal sulfide, and an alkali metal halide;

[0022] The halogen element X exists in the form of at least one of an alkaline earth metal halide and an alkali metal halide.

[0023] In some possible implementations, the G element is sulfur element S, and the sulfur element S exists in at least one of the form of alkali metal sulfide and elemental sulfur.

[0024] In another aspect, a method for preparing quantum dot glass is provided, the method comprising:

[0025] Providing raw materials for preparing quantum dot glass, wherein the elemental composition of the raw materials for preparing quantum dot glass conforms to the elemental composition of any of the above-mentioned raw materials for quantum dot glass;

[0026] Melting the raw materials for preparing the quantum dot glass to obtain molten glass liquid;

[0027] annealing the molten glass to obtain a glass intermediate;

[0028] The glass intermediate is heat-treated to precipitate quantum dots in a glass matrix, thereby obtaining the quantum dot glass.

[0029] The method for preparing quantum dot glass provided in the embodiments of the present disclosure sequentially melts, anneals, and heat-treats the raw materials used to prepare the quantum dot glass, thereby precipitating uniformly dispersed PbG quantum dots (e.g., PbS quantum dots) in a glass matrix to produce the quantum dot glass. This method is simple and convenient to operate, and the resulting quantum dot glass exhibits excellent luminous efficiency, mechanical stability, thermal stability, and chemical stability.

[0030] In some possible implementations, the temperature of the melt treatment is 1200° C. to 1500° C., and the time of the melt treatment is 30 minutes to 60 minutes;

[0031] The annealing treatment temperature is 300° C. to 400° C., and the annealing treatment time is 3 hours to 8 hours.

[0032] In some possible implementations, the heat treatment temperature is 540° C. to 650° C., and the heat treatment time is 1 hour to 48 hours.

[0033] Through the above heat treatment process, not only can PbG quantum dots be precipitated in the glass matrix, but also alkali metal halide crystals MX are gradually precipitated based on the PbG quantum dots as crystal nuclei.

[0034] During the heat treatment process, the particle size and distribution density of the PbG quantum dots, as well as the particle size and distribution density of the alkali metal halide crystals MX, can be adjusted by adjusting the heat treatment temperature and heat treatment time.

[0035] In another aspect, a method for preparing a quantum dot optical fiber core is provided, the method comprising:

[0036] Providing raw materials for preparing quantum dot glass, wherein the elemental composition of the raw materials for preparing quantum dot glass conforms to the elemental composition of any of the above-mentioned raw materials for quantum dot glass;

[0037] Melting the raw materials for preparing the quantum dot glass to obtain molten glass liquid;

[0038] Performing an optical fiber drawing process on the molten glass liquid to obtain a first optical fiber core preform;

[0039] annealing the first optical fiber preform to obtain a second optical fiber core preform;

[0040] The second optical fiber core preform is heat-treated to precipitate quantum dots in the glass matrix to obtain the quantum dot optical fiber core.

[0041] In some possible implementations, the temperature of the melt treatment is 1200° C. to 1500° C., and the time of the melt treatment is 30 minutes to 60 minutes;

[0042] The annealing temperature is 300°C to 400°C, and the annealing time is 3 hours to 8 hours;

[0043] The heat treatment temperature is 540° C. to 650° C., and the heat treatment time is 1 hour to 48 hours.

[0044] In another aspect, a quantum dot glass is provided, wherein the quantum dot glass is prepared using the above-mentioned quantum dot glass raw material, or using the above-mentioned method for preparing the quantum dot glass;

[0045] The quantum dot glass includes a glass matrix and a quantum dot system located within the glass matrix. The quantum dot system includes PbG quantum dots and alkali metal halide crystals located on the outer surface of the PbG quantum dots. The alkali metal halide crystals are composed of elements M and X, and the G element is sulfur S, selenium Se, or tellurium Te. Accordingly, the PbG quantum dots are PbS quantum dots, PbSe quantum dots, or PbTe quantum dots.

[0046] The quantum dot glass provided by the embodiments of the present disclosure has at least the following advantages: PbG quantum dots are formed in situ in the glass matrix, which not only facilitates the uniform dispersion of the PbG quantum dots, but also helps improve the stability of the PbG quantum dots. By adding a certain amount of halogen elements and alkali metal elements to the glass matrix, alkali metal halide crystals (abbreviated as MX crystals) can be formed. The MX crystals exist on the surface of the PbG quantum dots and the two are connected by halogen-lead bonds to achieve passivation of the PbG quantum dot surface, thereby effectively reducing the capture of carriers by surface defects of the PbG quantum dots and improving the luminous efficiency of the PbG quantum dots. Moreover, when the content of MX crystals is high and reaches the target threshold, it can be coated on at least part of the outer surface of the PbG quantum dots in the form of a shell layer, which not only helps improve the surface passivation effect of the PbG quantum dots, but also allows the PbG quantum dots to be protected by both the shell layer and the glass matrix, further improving the mechanical stability, thermal stability and chemical stability of the PbG quantum dots. In addition, the alkali metal halide crystals are also beneficial to reducing the melting temperature and viscosity of the glass melt and improving the uniformity of the glass matrix.

[0047] In some possible implementations, the alkali metal halide crystals exist in at least one of a first form and a second form;

[0048] The first form is a shell form, such that the alkali metal halide crystals cover at least a portion of the outer surface of the PbG quantum dots;

[0049] The second form is a dispersed crystal form, such that the alkali metal halide crystals are dispersed on the outer surface of the PbG quantum dots.

[0050] Regarding the shell morphology, one example is that the alkali metal halide crystals are fully encapsulated on the PbG quantum dots, and another example is that the alkali metal halide crystals are semi-encapsulated on the PbG quantum dots. The alkali metal halide crystals can exist in at least one of the fully encapsulated and semi-encapsulated forms.

[0051] In another aspect, a quantum dot optical fiber is provided, comprising a quantum dot optical fiber core, wherein the quantum dot optical fiber core is prepared using the above-mentioned quantum dot glass raw material, or using the above-mentioned method for preparing the quantum dot optical fiber core;

[0052] The quantum dot optical fiber core includes a glass matrix and a quantum dot system located within the glass matrix. The quantum dot system includes PbG quantum dots and alkali metal halide crystals located on the outer surface of the PbG quantum dots. The alkali metal halide crystals are composed of elements M and X, and the G element is sulfur S, selenium Se, or tellurium Te.

[0053] In some possible implementations, the alkali metal halide crystals exist in at least one of a first form and a second form;

[0054] The first form is a shell form, such that the alkali metal halide crystals cover at least a portion of the outer surface of the PbG quantum dots;

[0055] The second form is a dispersed crystal form, such that the alkali metal halide crystals are dispersed on the outer surface of the PbG quantum dots. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] FIG1 is an X-ray diffraction pattern of the original sample and a series of quantum dot glasses provided in Example 1;

[0057] FIG2 is an absorption spectrum of the original sample and a series of quantum dot glasses provided in Example 1;

[0058] FIG3 is a graph showing the luminescence spectra of a series of quantum dot glasses provided in Example 1;

[0059] FIG4 is a luminous efficiency test spectrum of the quantum dot glass numbered 58010 provided in Example 1;

[0060] FIG5 is an X-ray diffraction pattern of the original sample and a series of quantum dot glasses provided in Example 2;

[0061] FIG6 is an absorption spectrum diagram of the original sample and a series of quantum dot glasses provided in Example 2;

[0062] FIG7 is a graph showing the luminescence spectra of a series of quantum dot glasses provided in Example 2;

[0063] FIG8 is a transmission electron microscope image of the sample No. 59010 provided in Example 2;

[0064] FIG9 is a luminous efficiency test spectrum of the quantum dot glass No. 57010 provided in Example 2;

[0065] FIG10 is an X-ray diffraction pattern of the original sample and a series of quantum dot glasses provided in Example 3;

[0066] FIG11 is an absorption spectrum of the original sample and a series of quantum dot glasses provided in Example 3;

[0067] FIG12 is a graph showing the luminescence spectra of a series of quantum dot glasses provided in Example 3;

[0068] FIG13 is a luminous efficiency test spectrum of the quantum dot glass No. 59010 provided in Example 3;

[0069] FIG14 is an absorption spectrum of the original sample and a series of quantum dot glasses provided in Example 4;

[0070] FIG15 is a graph showing the luminescence spectra of a series of quantum dot glasses provided in Example 4;

[0071] FIG16 is a luminous efficiency test spectrum of quantum dot glasses numbered 57010, 58010, and 59010 provided in Example 4;

[0072] FIG17 is a graph showing the luminescence spectra of a series of quantum dot glasses provided in Example 5;

[0073] FIG18 is a graph showing the luminescence spectra of a series of quantum dot glasses provided in Example 6;

[0074] FIG19 is a graph showing the luminescence spectra of a series of quantum dot glasses provided in Example 7;

[0075] FIG20 is a graph showing the luminescence spectra of a series of quantum dot glasses provided in Example 8;

[0076] FIG21 is a structural layout diagram of an exemplary amplifier provided in an embodiment of the present disclosure.

[0077] In the X-ray diffraction patterns shown in Figures 1, 5, and 10, the horizontal coordinate Two theta (degree) refers to the 2θ diffraction angle, that is, the angle between the extended line of the incident X-ray and the reflected X-ray; the vertical coordinate Intensity (au) refers to the intensity, that is, the number of collected photons.

[0078] In the absorption spectra shown in Figures 2, 6, 11, and 14, the horizontal axis Wavelength (nm) refers to the wavelength, and the vertical axis Absorption coefficient (cm -1 ) refers to the absorption coefficient, which represents the absorption of light per unit length in a medium.

[0079] In the luminescence spectra shown in Figures 3, 7, 12, 15, 17, 18, 19, and 20, the horizontal axis Wavelength (nm) refers to the wavelength, and the vertical axis PL intensity (au) refers to the photoluminescence intensity.

[0080] In the luminous efficiency curves shown in FIG4 , FIG9 , FIG13 , and FIG16 , the abscissa Wavelength (nm) refers to the wavelength, and the ordinate Intensity (au) refers to the intensity. DETAILED DESCRIPTION

[0081] Preparation methods for PbS quantum dots include chemical synthesis, sol-gel, and melt processes. Chemically synthesized PbS colloidal quantum dots offer simple surface modification and high operability. However, quantum dots dispersed in solution are prone to aggregation, photooxidation, and poor thermal stability, limiting their application. The melt process uses a heat treatment process to grow quantum dots in a glass matrix. This not only prevents aggregation but also improves the chemical, thermal, and mechanical stability of the quantum dots.

[0082] However, due to the small size and large specific surface area of ​​quantum dots, they have many surface defects, such as many dangling bonds, which leads to low luminescence efficiency. Therefore, it is necessary to passivate the surface defects of quantum dots.

[0083] Compared with chemically synthesized PbS quantum dots, quantum dot glass synthesized by the melt method (also known as quantum dot dispersed glass) is coated with a glass matrix, which makes it impossible to passivate the surface defects of the PbS quantum dots by using surface ligands or other methods after the synthesis of the PbS quantum dots. This leads to serious surface defects of the PbS quantum dots, and light traps generate electrons and vacancies, which seriously reduce the luminescence efficiency of the PbS quantum dots and limit their application.

[0084] To address the technical problems of the related art, the present invention provides a quantum dot glass raw material comprising the following elements in molar percentages: Si: 4.96% to 21.05%; B: 3.51% to 19.85%; Al: 0% to 7.44%; G: 0.29% to 3.16%; Pb: 0.03% to 0.5%; O: 49.15% to 60.31%; N: 1.62% to 8.77%; M: 5.28% to 18.49%; and X: 0.7% to 8.16%. The G element is sulfur (S), selenium (Se), or tellurium (Te); the N element is an alkaline earth metal; the M element is an alkali metal; and the X element is a halogen element.

[0085] The quantum dot glass raw material provided in the embodiments of the present disclosure can be used to prepare quantum dot glass containing PbG quantum dots, which can be PbS quantum dots, PbSe quantum dots, or PbTe quantum dots. Specifically, when the G element is sulfur (S), the quantum dot glass raw material is used to prepare quantum dot glass containing PbS quantum dots; when the G element is selenium (Se), the quantum dot glass raw material is used to prepare quantum dot glass containing PbSe quantum dots; and when the G element is tellurium (Te), the quantum dot glass raw material is used to prepare quantum dot glass containing PbTe quantum dots.

[0086] The quantum dot glass raw materials provided by the embodiments of the present disclosure can be used to prepare quantum dot glass products. Based on the synergistic effect of the aforementioned elements at specific molar percentages, the prepared quantum dot glass products have at least the following advantages: PbG quantum dots are formed in situ within the glass matrix, which not only facilitates uniform dispersion of the PbG quantum dots but also improves their stability. By adding a certain amount of halogen elements and alkali metal elements to the raw materials, alkali metal halide crystals (MX crystals) can be formed. The MX crystals are present on the surface of the PbG quantum dots, and the two are connected by halogen-lead bonds, thereby passivating the PbG quantum dot surface. This effectively reduces carrier capture by surface defects in the PbG quantum dots and improves the luminescence efficiency of the PbG quantum dots. Furthermore, when the MX crystal content reaches a high level and reaches a target threshold, it can form a shell layer covering at least a portion of the outer surface of the PbG quantum dots. This not only enhances the surface passivation effect of the PbG quantum dots, but also allows the PbG quantum dots to be protected by both the shell layer and the glass matrix, further improving the mechanical, thermal, and chemical stability of the PbG quantum dots. In addition, the alkali metal halide crystals are also beneficial to reducing the melting temperature and viscosity of the glass melt and improving the uniformity of the glass matrix.

[0087] Taking G as an example, where the element is sulfur (S), PbS quantum dots are formed in situ in a glass matrix, which not only facilitates the uniform dispersion of the PbS quantum dots but also improves their thermal, chemical, and mechanical stability. By adding a certain amount of halogen elements to the matrix and cooperating with alkali metal elements to form alkali halide crystals, which exist on the surface of the PbG quantum dots and are connected by halogen-lead bonds, the surface of the PbS quantum dots is passivated, effectively reducing carrier capture by surface defects in the PbS quantum dots and improving their luminescence efficiency.

[0088] In some examples, in the quantum dot glass raw material provided by the embodiments of the present disclosure, the sum of the molar percentages of Si, B, Al, G, Pb, O, N, M, and X is 100%.

[0089] In combination with the above-mentioned mole percentages of the elements in the quantum dot glass raw materials, some applicable mole percentages of these elements are exemplified below.

[0090] Illustratively, the molar percentage of Si element includes, but is not limited to, 4.96%, 4.98%, 5%, 5.05%, 6%, 6.05%, 7%, 7.05%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 12.6%, 12.7%, 12.8%, 12.9%, 13%, 13.1%, 13. 2%, 13.3%, 13.4%, 13.5%, 13.6%, 13.7%, 13.8%, 13.9%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, 19.5%, 20%, 20.01%, 20.02%, 20.03%, 20.04%, 20.05%, etc.

[0091] Illustratively, the molar percentage of element B includes, but is not limited to, 3.51%, 3.55%, 3.6%, 3.65%, 3.7%, 3.75%, 3.8%, 3.85%, 3.9%, 3.95%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, 19.5%, etc.

[0092] Illustratively, the molar percentage of the Al element includes, but is not limited to, 0.05%, 0.1%, 0.15%, 0.18%, 0.19%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.4%, etc.

[0093] Illustratively, the molar percentage of the G element includes, but is not limited to, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.1%, 3.15%, etc.

[0094] In some examples, the G element is S. Considering that S is easily volatile, when used, the molar percentage of S is greater than the molar percentage of Pb. For example, the molar percentage of sulfur S to the molar percentage of Pb is 2 to 20:1.

[0095] For example, the molar percentage of Pb element is, but is not limited to, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, .25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.4%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.5%, etc.

[0096] Illustratively, the molar percentage of the alkaline earth metal N element is, but is not limited to, 1.63%, 1.64%, 1.65%, 1.66%, 1.67%, 1.69%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6% , 4.7%, 4.8%, 4.9%, 5.0%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8%, 6.9%, 7.0%, 7.1%, 7.2%, 7.3%, 7.4%, 7.5%, 7.6%, 7.7%, 7.8%, 7.9%, 8.0%, 8.1%, 8.2%, 8.3%, 8.4%, 8.5%, 8.6%, 8.7%, etc.

[0097] Illustratively, the molar percentage of the alkali metal element M is, but is not limited to, 5.5%, 5.8%, 6%, 6.2%, 6.5%, 6.7%, 6.9%, 7%, 7.2%, 7.5%, 7.7%, 7.9%, 8%, 8.2%, 8.5%, 8.7%, 8.9%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.3%, 12.5%, 12.6%, 12.7%, 12.9%, 12.8%, 12.9%, 12.9%, 12.1%, 12.2%, 12.3%, 12.5%, 12.6%, 12.7%, 12.9%, 12.8%, 12.9%, 12.9%, 12.1% and 12.5%. .8%, 13%, 13.3%, 13.5%, 13.8%, 14%, 14.3%, 14.5%, 14.8%, 15%, 15.2%, 15.5%, 15.7%, 16%, 16.2%, 16.5%, 16.7%, 17%, 17.2%, 17.5%, 17.7%, 17.9%, 18%, 18.1%, 18.2%, 18.3%, 18.4%, etc.

[0098] Illustratively, the molar percentage of the halogen element X is, but is not limited to, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2% , 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5.0%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8%, 6.9%, 7.0%, 7.1%, 7.2%, 7.3%, 7.4%, 7.5%, 7.6%, 7.7%, 7.8%, 7.9%, 8.0%, 8.1%, etc.

[0099] In the disclosed embodiments, the alkaline earth metal element N is selected from at least one of Sr, Ca, and Ba. That is, the alkaline earth metal element N can be any one, any two, or all three. Sr, Ca, and Ba are selected as the alkaline earth metal element N. These elements exist as glass network intermediates in quantum dot glass products, improving the thermal and chemical stability of the quantum dot glass products.

[0100] The alkali metal element M is at least one selected from the group consisting of Na, K, and Li. That is, the alkali metal element M may be any one of them, any two of them, or all three of them.

[0101] Na, K, and Li are selected as the alkali metal element M, and the molar percentage of the alkali metal element M is greater than the molar percentage of the halogen element X. This allows a portion of the alkali metal element M to combine with the halogen element X to form alkali halide crystals that bind to the outer surface of the PbS quantum dots, thereby passivating surface defects in the PbS quantum dots and improving luminescence efficiency. The remaining alkali metal element M exists as a glass network intermediate in the quantum dot glass product and also acts as a flux.

[0102] The halogen element X is selected from at least one of Cl, Br and I, that is, the halogen element X can be any one of them, any two of them, or all three of them.

[0103] Cl, Br, and I are selected as X elements. They are compounded with the alkali metal element M to form alkali metal halide crystals and bind to the outer surface of the PbS quantum dots, thereby passivating the surface defects of the PbS quantum dots and improving the luminous efficiency.

[0104] In the quantum dot product involved in the embodiments of the present disclosure, the alkali metal halide crystals exist in at least one of a first form and a second form. The first form is a shell form, so that the alkali metal halide crystals are coated on at least part of the outer surface of the PbS quantum dot, and the two are connected by a halogen-lead bond. The second form is a dispersed crystal form, so that the alkali metal halide crystals are dispersedly distributed on the outer surface of the PbS quantum dot, and the two are connected by a halogen-lead bond. The "dispersed form" involved here can include a single alkali metal halide crystal dispersedly arranged, and can also include multiple alkali metal halide crystals agglomerated or combined into clusters, and dispersedly arranged in clusters. Both of the above forms can achieve passivation of surface defects of PbS quantum dots.

[0105] The existence form of alkali metal halide crystals in the glass matrix is ​​adjusted by adjusting the content of the halogen element X. Generally, when the content of the halogen element X is higher, it is easier to form a shell morphology. Conversely, when the content of the halogen element X is lower, it may not be sufficient to form a shell, so that it is dispersed on the outer surface of the PbS quantum dots.

[0106] The quantum dot glass raw materials provided in the embodiments of the present disclosure each element exists in at least one of a simple substance form and a compound form, so as to facilitate the acquisition of quantum dot glass raw materials and thus facilitate the preparation of glass products. The existence form of each element is exemplarily described below.

[0107] In the raw materials used to make quantum dot glass, Si exists in the form of silicon oxide, for example, silicon dioxide (SiO2). In the glass product, Si combines with O and acts as a glass former.

[0108] In the raw materials used to make quantum dot glass, the boron element exists in the form of boron oxide, for example, boron oxide (B2O3). In the glass product, the boron element combines with the oxygen element and acts as a glass former.

[0109] In the raw materials used to make quantum dot glass, Al exists in the form of aluminum oxide, for example, aluminum oxide (Al2O3). In the glass product, Al combines with O and acts as a glass former.

[0110] In the raw materials used to prepare quantum dot glass, the G element exists in at least one of the MG form and the G elemental form. For example, the MG form can be Na2G, K2G, Li2G, etc. In the glass product, the G element exists in the form of PbG quantum dots.

[0111] For example, the G element is S, which exists in at least one of an alkali metal sulfide and elemental sulfur. Examples of alkali metal sulfides include sodium sulfide (Na2S), potassium sulfide (K2S), and lithium sulfide (Li2S). In glass products, S exists in the form of PbS quantum dots.

[0112] In the raw materials used to make quantum dot glass, the Pb element exists in at least one of the following forms: lead oxide (PbO) and single-element lead. In the glass product, the Pb element exists in the form of PbS quantum dots.

[0113] The alkaline earth metal element N exists in the form of at least one of an alkaline earth metal carbonate and an alkaline earth metal halide. For example, the alkaline earth metal carbonate may be at least one of strontium carbonate (SrCO3), calcium carbonate (CaCO3), and barium carbonate (BaCO3). For example, the alkaline earth metal halide may be at least one of strontium chloride (SrCl2), strontium bromide (SrBr2), strontium iodide (SrI2), calcium chloride (CaCl2), calcium bromide (CaBr2), calcium iodide (CaI2), barium chloride (BaCl2), barium bromide (BaBr2), and barium iodide (BaI2). During the melting process, the carbon element evaporates as a gas. Furthermore, in the glass product, the alkaline earth metal element N combines with the oxygen element and serves as a glass intermediate.

[0114] In the raw materials used to prepare quantum dot glass, the alkali metal element M exists in the form of at least one of an alkali metal carbonate, an alkali metal sulfide, and an alkali metal halide. For example, an alkali metal carbonate can be at least one of sodium carbonate (Na2CO3), potassium carbonate (K2CO3), and lithium carbonate (Li2CO3). Alkali metal sulfides are used to prepare PbS quantum dots. For example, alkali metal sulfides can be at least one of sodium sulfide (Na2S), potassium sulfide (K2S), and lithium sulfide (Li2S). During the melting process, the C element evaporates as a gas. Furthermore, in the glass product, a portion of the alkali metal element M combines with the halogen element X to form MX crystals, which serve as the shell of the PbS quantum dots. The remaining alkali metal element serves as a glass network intermediate.

[0115] In the raw materials for preparing quantum dot glass, the halogen element X is present in the form of at least one of an alkaline earth metal halide and an alkali metal halide. For example, the alkaline earth metal halide may be at least one of strontium chloride (SrCl2), strontium bromide (SrBr2), strontium iodide (SrI2), calcium chloride (CaCl2), calcium bromide (CaBr2), calcium iodide (CaI2), barium chloride (BaCl2), barium bromide (BaBr2), and barium iodide (BaI2). For example, the alkali metal halide may be at least one of sodium chloride (NaCl), sodium bromide (NaBr), sodium iodide (NaI), potassium chloride (KCl), potassium bromide (KBr), potassium iodide (KI), lithium chloride (LiCl), lithium bromide (LiBr), and lithium iodide (LiI).

[0116] On the other hand, the present disclosure also provides a method for preparing quantum dot glass, which comprises the following steps:

[0117] Step S11: providing raw materials for preparing quantum dot glass, wherein the element composition of the raw materials for preparing quantum dot glass conforms to the element composition of any of the above-mentioned raw materials for quantum dot glass.

[0118] Step S12: melting the raw materials for preparing the quantum dot glass, placing the molten glass liquid in a mold and cooling it to form a glass precursor.

[0119] Step S13: annealing the glass precursor to obtain a glass intermediate.

[0120] Step S14: heat-treating the glass intermediate to precipitate quantum dots in the glass matrix to obtain quantum dot glass.

[0121] The method for preparing quantum dot glass provided in the embodiments of the present disclosure sequentially melts, anneals, and heat-treats the raw materials used to prepare the quantum dot glass, thereby precipitating uniformly dispersed PbG quantum dots (e.g., PbS quantum dots) in a glass matrix to produce the quantum dot glass. This method is simple and convenient to operate, and the resulting quantum dot glass exhibits excellent luminous efficiency, mechanical stability, thermal stability, and chemical stability.

[0122] In step S11 , raw materials for preparing quantum dot glass are provided, and the element composition of the raw materials for preparing quantum dot glass conforms to the element composition of any of the above-mentioned raw materials for quantum dot glass.

[0123] As described above, the B element exists in the form of boron oxide; the Al element exists in the form of aluminum oxide; the G element exists in at least one of the MG form and the G element form; the Pb element exists in at least one of the lead oxide form and the lead element form; the alkaline earth metal element N exists in at least one of the alkaline earth metal carbonate form and the alkaline earth metal halide form; the alkali metal element M exists in at least one of the alkali metal carbonate form, the alkali metal sulfide form and the alkali metal halide form; and the halogen element X exists in at least one of the alkaline earth metal halide form and the alkali metal halide form.

[0124] For each element, the existence form of each element is determined and used as a component in the raw material for preparing quantum dot glass. According to the molar ratio of the elements in the above-mentioned quantum dot glass raw materials, the ratio of each component in the raw material for preparing quantum dot glass is determined, thereby obtaining the raw material for preparing quantum dot glass.

[0125] In some examples, each component of the raw material for preparing the quantum dot glass is accurately weighed according to the ratio, put into a mortar and ground thoroughly to mix evenly, and then step S12 is performed.

[0126] In step S12, the raw materials for preparing the quantum dot glass are melted, and the molten glass is placed in a mold and cooled to form a glass precursor. For example, the raw materials for preparing the quantum dot glass can be placed in a sealed crucible and melted to obtain a molten glass. However, PbS quantum dots are not formed in the molten glass.

[0127] Some applicable melt treatment temperatures are 1200°C to 1500°C, including but not limited to: 1200°C, 1250°C, 1300°C, 1350°C, 1400°C, 1450°C, 1500°C, etc., and some applicable melt treatment times are 30 minutes to 60 minutes, including but not limited to: 30 minutes, 40 minutes, 50 minutes, 60 minutes, etc.

[0128] In step S13, the glass precursor is annealed to obtain a glass intermediate, thereby eliminating residual stress. The obtained glass intermediate is yellow and transparent.

[0129] Some applicable annealing treatment temperatures are 300°C to 400°C, including but not limited to: 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, etc., and the annealing treatment time is 3 hours to 8 hours, including but not limited to: 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, etc.

[0130] In step S14, the glass intermediate is heat-treated to precipitate quantum dots in the glass matrix to obtain quantum dot glass.

[0131] Illustratively, the temperature of the heat treatment is 540°C to 650°C, including but not limited to 540°C, 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, etc.

[0132] The heat treatment time is 1 hour to 48 hours, which includes but is not limited to: 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, 31 hours, 32 hours, 33 hours, 34 hours, 35 hours, 36 hours, 37 hours, 38 hours, 39 hours, 40 hours, 41 hours, 42 hours, 43 hours, 44 hours, 45 hours, 46 hours, 47 hours, 48 ​​hours, etc.

[0133] Through the above-mentioned heat treatment process, not only can PbG quantum dots be precipitated in the glass matrix, but also, based on the PbG quantum dots as crystal nuclei, alkali metal halide crystals MX are gradually precipitated, and the two cooperate to form a quantum dot system.

[0134] In some examples, heat treating the glass intermediate includes sequentially performing a first heat treatment and a second heat treatment on the glass intermediate, wherein at least one of a temperature and a heat treatment time of the second heat treatment is greater than at least one of a temperature and a heat treatment time of the first heat treatment.

[0135] The first step of heat treatment is to facilitate the full precipitation of PbG quantum dots, and the full precipitation of alkali metal halide crystals MX is facilitated by increasing the temperature or extending the heat treatment time. During the heat treatment process, the particle size and distribution density of PbG quantum dots, as well as the particle size and distribution density of alkali metal halide crystals MX, can be adjusted by adjusting the heat treatment temperature and heat treatment time.

[0136] The heat treatment process, also known as the glass crystallization process, includes two stages: nucleation and crystal growth. The higher the heat treatment temperature, the faster the nucleus growth rate, and the longer the heat treatment time, the larger the crystal size. Therefore, by controlling the heat treatment time and temperature, PbG quantum dots with high density and desired size can be obtained.

[0137] In another aspect, the present disclosure further provides a method for preparing a quantum dot optical fiber core, the method comprising the following steps:

[0138] Step S21 : providing raw materials for preparing quantum dot glass, wherein the element composition of the raw materials for preparing quantum dot glass conforms to the element composition of any of the above-mentioned raw materials for quantum dot glass.

[0139] Step S22: Melt the raw materials for preparing quantum dot glass, place the molten glass liquid in a mold, cool and shape it, and obtain a glass precursor.

[0140] Step S23: performing optical fiber drawing processing on the glass precursor to obtain a first optical fiber core preform.

[0141] Step S24: annealing the first optical fiber preform to obtain a second optical fiber core preform.

[0142] Step S25: heat-treating the second optical fiber core preform to precipitate quantum dots in the glass matrix to obtain a quantum dot optical fiber core.

[0143] The method for preparing a quantum dot optical fiber core provided in the embodiments of the present disclosure sequentially melts, draws the optical fiber, anneals, and then heat-treats the raw materials used to prepare quantum dot glass. This method precipitates uniformly dispersed PbG quantum dots within a glass matrix, producing quantum dot glass. This method is simple and convenient to operate, and the resulting quantum dot optical fiber core exhibits excellent luminous efficiency, mechanical stability, thermal stability, and chemical stability.

[0144] Illustratively, the temperature of the melt treatment is 1200°C to 1500°C, and the time of the melt treatment is 30 minutes to 60 minutes; the temperature of the annealing treatment is 300°C to 400°C, and the time of the annealing treatment is 3 hours to 8 hours; the temperature of the heat treatment is 540°C to 650°C, and the time of the heat treatment is 1 hour to 48 hours.

[0145] Among them, for step S21, step S22, step S24, and step S25, please refer to the relevant descriptions of step S11, step S12, step S13, and step S14 respectively, and will not be repeated here.

[0146] In step S23, the glass precursor is subjected to an optical fiber drawing process to obtain a first optical fiber core preform. The drawing process can be performed using existing optical fiber preform drawing technology.

[0147] On the other hand, the embodiments of the present disclosure further provide a quantum dot glass, which is prepared using any of the above-mentioned quantum dot glass raw materials, or using any of the above-mentioned quantum dot glass preparation methods.

[0148] The quantum dot glass includes a glass matrix and a quantum dot system located within the glass matrix. The quantum dot system includes PbG quantum dots and alkali metal halide crystals located on the outer surface of the PbG quantum dots. The alkali metal halide crystals are composed of elements M and X. The G element is sulfur S, selenium Se, or tellurium Te. Correspondingly, the PbG quantum dots are PbS quantum dots, PbSe quantum dots, or PbTe quantum dots.

[0149] The quantum dot glass provided by the embodiments of the present disclosure has at least the following advantages: PbG quantum dots are formed in situ in the glass matrix, which not only facilitates the uniform dispersion of the PbG quantum dots, but also helps improve the stability of the PbG quantum dots. By adding a certain amount of halogen elements and alkali metal elements to the glass matrix, alkali metal halide crystals (abbreviated as MX crystals) can be formed. The MX crystals exist on the surface of the PbG quantum dots and the two are connected by halogen-lead bonds to achieve passivation of the PbG quantum dot surface, thereby effectively reducing the capture of carriers by surface defects of the PbG quantum dots and improving the luminous efficiency of the PbG quantum dots. Moreover, when the content of MX crystals is high and reaches the target threshold, it can be coated on at least part of the outer surface of the PbG quantum dots in the form of a shell layer, which not only helps improve the surface passivation effect of the PbG quantum dots, but also allows the PbG quantum dots to be protected by both the shell layer and the glass matrix, further improving the mechanical stability, thermal stability and chemical stability of the PbG quantum dots. In addition, the alkali metal halide crystals are also beneficial to reducing the melting temperature and viscosity of the glass melt and improving the uniformity of the glass matrix.

[0150] The alkali metal halide crystals exist in at least one of a first form and a second form. The first form is a shell form, in which the alkali metal halide crystals coat at least a portion of the outer surface of the PbG quantum dots, and the two are connected by halide-lead bonds. The second form is a dispersed crystal form, in which the alkali metal halide crystals are dispersed on the outer surface of the PbG quantum dots, and the two are connected by halide-lead bonds. The "dispersed form" referred to here can include a single alkali metal halide crystal dispersed in a clustered arrangement, or multiple alkali metal halide crystals aggregated or combined into clusters and dispersed in a clustered arrangement. Both of these forms can passivate surface defects in PbG quantum dots.

[0151] Regarding the shell morphology, one example is that the alkali metal halide crystals are fully encapsulated on the PbG quantum dots, and another example is that the alkali metal halide crystals are semi-encapsulated on the PbG quantum dots (i.e., not completely encapsulating the outer surface of the PbG quantum dots). The alkali metal halide crystals can exist in at least one of the fully encapsulated and semi-encapsulated forms.

[0152] In some examples, quantum dots include PbG quantum dots, a shell of MX1 crystals coating the outer surface of the PbG quantum dots, and MX2 crystals dispersed on the outer surface of the PbG quantum dots. The elements X1 and X2 are different. The MX2 crystals are dispersed on the outer surface of the PbG quantum dots and also serve to passivate surface defects in the PbG quantum dots. For example, X1 is Cl and X2 is Br or I.

[0153] The quantum dot glass provided in the embodiment of the present disclosure can adjust the particle size of the PbG quantum dots by adjusting the heat treatment process, thereby achieving the regulation of the absorption and luminescence of the quantum dot glass within the 900nm-2400nm band.

[0154] In some examples, the quantum dot glass provided by the embodiments of the present disclosure contains PbS quantum dots (lead sulfide quantum dots) and alkali metal halide crystals MX located on the outer surface of the PbS quantum dots.

[0155] In yet another aspect, embodiments of the present disclosure further provide a quantum dot optical fiber (also known as a quantum dot glass optical fiber), comprising a quantum dot optical fiber core, the quantum dot optical fiber core being prepared using any of the aforementioned quantum dot glass raw materials, or using any of the aforementioned methods for preparing a quantum dot optical fiber core. The quantum dot optical fiber core comprises a glass matrix and a quantum dot system within the glass matrix, the quantum dot system comprising PbG quantum dots and alkali metal halide crystals located on the outer surface of the PbG quantum dots, the alkali metal halide crystals being composed of elements M and X.

[0156] The quantum dot optical fiber provided by the embodiments of the present disclosure has at least the following advantages: PbG quantum dots are formed in situ in a glass matrix, which not only facilitates the uniform dispersion of the PbG quantum dots but also improves their stability. By adding a certain amount of halogen elements and alkali metal elements to the matrix, alkali metal halide crystals (MX crystals) can be formed. The MX crystals are present on the surface of the PbG quantum dots, and the two are connected by halogen-lead bonds, thereby passivating the PbG quantum dot surface, effectively reducing carrier capture by surface defects in the PbG quantum dots and improving the luminescence efficiency of the PbG quantum dots. Furthermore, when the MX crystal content is high and reaches a target threshold, it can form a shell covering at least a portion of the outer surface of the PbG quantum dots. This not only improves the surface passivation effect of the PbG quantum dots, but also allows the PbG quantum dots to be protected by both the shell and the glass matrix, further improving the mechanical, thermal, and chemical stability of the PbG quantum dots. In addition, the alkali metal halide crystals are also beneficial to reducing the melting temperature and viscosity of the glass melt and improving the uniformity of the glass matrix.

[0157] The alkali metal halide crystals exist in at least one of a first form and a second form. The first form is a shell form, where the alkali metal halide crystals coat at least a portion of the outer surface of the PbG quantum dots, and the two are connected via a halogen-lead bond. The second form is a dispersed crystal form, where the alkali metal halide crystals are dispersed on the outer surface of the PbG quantum dots, and the two are connected via a halogen-lead bond.

[0158] Regarding the alkali metal halide crystals in the core of quantum dot optical fiber, please refer to the above description of quantum dot glass.

[0159] The quantum dot optical fiber provided in the embodiment of the present disclosure can adjust the particle size of the PbG quantum dots by adjusting the heat treatment process, thereby achieving the regulation of the absorption and luminescence of the quantum dot optical fiber core within the 900nm-2400nm band.

[0160] In some examples, the quantum dot optical fiber provided by the embodiments of the present disclosure contains PbS quantum dots and alkali metal halide crystals located on the outer surface of the PbS quantum dots.

[0161] Of course, the quantum dot glass product involved in the embodiments of the present disclosure can be not only the above-mentioned quantum dot glass and quantum dot optical fiber, but also rod-shaped glass.

[0162] The quantum dot glass or quantum dot optical fiber provided in the embodiments of the present disclosure can adjust the absorption spectrum and the luminescence spectrum in the near-infrared to mid-infrared band, giving it great application potential in the fields of infrared detection and near-infrared fluorescence.

[0163] Fiber amplifiers are crucial components in fiber-optic communication lines. In backbone long-distance optical communication networks, signal power attenuates as transmission distance increases. Therefore, amplifiers are needed to amplify the signal at intervals. A typical amplifier is an erbium-doped fiber amplifier (EDFA). Its operating principle is to couple signal and pump light into an erbium-doped fiber through a wavelength division multiplexer (WDM). An isolator is also included to ensure forward transmission of the optical signal.

[0164] The current noise figure of erbium-doped fiber amplifiers is relatively high. One implementation scheme is to replace the existing erbium-doped fiber with the quantum dot glass or quantum dot fiber provided by the embodiments of the present disclosure to obtain a new amplifier, thereby achieving a lower noise figure.

[0165] Among them, the central wavelength of the new amplifier based on the quantum dot glass product of the embodiment of the present disclosure can be controlled by the central particle size of the quantum dots, and the operating bandwidth can be controlled by the size distribution of the quantum dots. The central particle size and size distribution of the quantum dots can be controlled by different heat treatment conditions, thereby providing a new way to expand the optical fiber communication band and industrial applications.

[0166] For example, referring to Figure 21, an amplifier structure includes: a signal source 1, an isolator 2, a wavelength division multiplexer 3, a pump source 4, and a quantum dot glass product 5 (including quantum dot glass or quantum dot fiber). Signal light is output from signal source 1 and enters isolator 2 to ensure forward transmission of the optical signal. It then enters wavelength division multiplexer 3, where it enters quantum dot glass product 5 for optical amplification and output. At the same time, pump light is output from pump source 4, passes through wavelength division multiplexer 3, and then enters quantum dot glass product 5 and quantum dot glass fiber 6. After the signal light and pump light are coupled in the wavelength division multiplexer, they enter quantum dot glass product 5 for signal amplification and output.

[0167] The exemplary embodiments of the present disclosure will be described in more detail below. Although the exemplary embodiments of the present disclosure are described below, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or in accordance with the product specifications are used. Where the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0168] The following Examples 1 to 8 all provide a quantum dot glass raw material. The formulas of these quantum dot glass raw materials are shown in Table 1. “ / ” in Table 1 indicates that the item does not exist.

[0169] Among them, in the raw materials for preparing the quantum dot glass of Examples 1 to 8, the Si element exists in the form of silicon dioxide (SiO2); the B element exists in the form of boron oxide (B2O3); the Al element exists in the form of aluminum oxide (Al2O3); the S element exists in the form of sodium sulfide (Na2S) and / or in the form of S element; the Pb element exists in the form of lead oxide (PbO); the alkaline earth metal elements exist in the form of alkaline earth metal carbonate compounds, for example, the Ca element exists in the form of calcium carbonate (CaCO3), the Sr element exists in the form of strontium carbonate (SrCO3), and the Ba element exists in the form of barium carbonate (BaCO3). The alkali metal element M exists in the form of an alkali metal carbonate compound and an alkali metal halide. For example, the Na element exists in the form of sodium carbonate (Na2CO3) and at least one of sodium chloride (NaCl), sodium bromide (NaBr), and sodium iodide (NaI). The K element exists in the form of potassium carbonate (K2CO3) and at least one of potassium chloride (KCl), potassium bromide (KBr), and potassium iodide (KI). The Li element exists in the form of lithium carbonate (Li2CO3) and at least one of lithium chloride (LiCl), lithium iodide (LiI), or lithium bromide (LiBr). The halogen element X exists in the form of an alkali metal halide. For example, the Cl element exists in the form of sodium chloride (NaCl) or potassium chloride (KCl), the Br element exists in the form of sodium bromide (NaBr), and the I element exists in the form of sodium iodide (NaI).

[0170] Table 1

[0171] Example 1

[0172] Quantum dot glass is prepared in Example 1, and is prepared by the following method: providing uniformly mixed raw materials for preparing quantum dot glass, wherein the elemental composition of the raw materials for preparing quantum dot glass conforms to the elemental composition of the raw materials for preparing quantum dot glass in Example 1 in Table 1. The raw materials for preparing quantum dot glass are placed in a crucible for melting treatment, the melting temperature is 1500°C, and the melting time is 60 minutes to obtain molten glass liquid. After the molten glass liquid is cooled, a glass precursor is formed, which is transferred to an annealing furnace for annealing treatment, the annealing temperature is 400°C, and the annealing time is 5 hours to obtain a yellow transparent glass intermediate. The glass intermediate is transferred to a heat treatment furnace for heat treatment, and the heat treatment is carried out at 570°C-590°C for 10 hours or 20 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on its surface in the glass matrix to obtain a series of quantum dot glasses.

[0173] The series of quantum dot glasses prepared in Example 1 are PbS / NaBr core-shell quantum dot glasses, which have PbS quantum dots in the glass matrix and a NaBr shell layer located on the outer surface of the PbS quantum dots.

[0174] The following tests were conducted on a series of quantum dot glasses prepared in Example 1. These quantum dot glasses were heat-treated at 570°C, 580°C, and 590°C for 10 hours, respectively. These quantum dot glasses were numbered 57010, 58010, and 59010, respectively. Furthermore, another quantum dot glass was heat-treated at 580°C for 20 hours, and thus numbered 58020.

[0175] The glass intermediate involved in Example 1 is called the original sample (AP for short). X-ray diffraction analysis (XRD) was performed on the original sample provided in Example 1 and a series of quantum dot glasses. The obtained X-ray diffraction patterns are shown in Figure 1. As shown in Figure 1, the AP sample only has the "mantou peak" of the glass phase and no crystal diffraction peak. However, after heat treatment, a series of quantum dot glasses showed a crystal diffraction peak at 570°C, and the diffraction peak matched the diffraction peak of NaBr crystals, indicating that NaBr crystals were precipitated in the glass. As the heat treatment temperature increases, the size of the NaBr crystals gradually grows, and the corresponding diffraction peak intensity gradually increases.

[0176] Absorption spectra were tested on the original sample provided in Example 1 and a series of quantum dot glasses. As shown in Figure 2, the AP sample exhibits no absorption peak. However, as the heat treatment temperature increases, the absorption peak of the quantum dot glass gradually shifts toward longer wavelengths. This indicates that PbS / NaBr core-shell quantum dots are precipitated in the glass sample prepared in Example 1, and the size of the PbS quantum dots increases with increasing heat treatment temperature.

[0177] Luminescence spectra (also known as fluorescence spectra) were tested on a series of quantum dot glasses provided in Example 1 at an excitation wavelength of 800 nm. As shown in FIG3 , the AP sample had no fluorescence peak. However, as the heat treatment temperature increased, the fluorescence peak of the quantum dot glass gradually shifted to the long-wavelength band. This indicates that PbS / NaBr core-shell structure quantum dots were precipitated in the glass sample prepared in Example 1, and the size of the PbS quantum dots gradually increased with increasing heat treatment temperature and extending heat treatment time.

[0178] The luminous efficiency of the quantum dot glass provided in Example 1 was tested. The heat treatment temperature and time of the quantum dot glass were 580°C / 10 hours, respectively, and the excitation wavelength was 650nm. The test results are shown in Figure 4, where the solid dark gray squares in Figure 4 represent the luminescence spectrum of the 650nm excitation light source, and the hollow circles represent the luminescence spectrum of the quantum dot glass. As shown in Figure 4, under the excitation of the 650nm wavelength light source, the luminous efficiency of the quantum dot glass is as high as 75%. This is because the alkali metal halide crystals effectively passivate the surface defects of the PbS quantum dots, thereby effectively improving the luminous efficiency of the quantum dots.

[0179] Example 2

[0180] Quantum dot glass was prepared in Example 2, and was prepared by the following method: providing uniformly mixed raw materials for preparing quantum dot glass, wherein the elemental composition of the raw materials for preparing quantum dot glass conforms to the elemental composition of the raw materials for preparing quantum dot glass in Example 2 in Table 1. The raw materials for preparing quantum dot glass were placed in a crucible for melting treatment, the melting temperature was 1380°C, and the melting time was 60 minutes to obtain molten glass liquid. After the molten glass liquid was cooled, a glass precursor was formed, which was transferred to an annealing furnace for annealing treatment, the annealing temperature was 380°C, and the annealing time was 5 hours to obtain a yellow transparent glass intermediate. The glass intermediate was transferred to a heat treatment furnace for heat treatment, and the heat treatment was carried out at 550°C-600°C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on its surface in the glass matrix to obtain a series of quantum dot glasses.

[0181] The series of quantum dot glasses prepared in Example 2 are PbS / NaCl core-shell quantum dot glasses, which have PbS quantum dots in the glass matrix and a NaCl shell layer located on the outer surface of the PbS quantum dots.

[0182] The following tests were performed on a series of quantum dot glasses prepared in Example 2, wherein the heat treatment temperatures of these quantum dot glasses were 550°C, 560°C, 570°C, 580°C, 590°C, and 600°C, respectively, and the heat treatment time was 10 hours, so the numbers of these quantum dot glasses were defined as: 55010, 56010, 57010, 58010, 59010, and 60010, respectively.

[0183] The glass intermediate involved in Example 2 is called the original sample (AP for short). The original sample provided in Example 2 and a series of quantum dot glasses were subjected to X-ray diffraction treatment, and the obtained X-ray diffraction patterns are shown in Figure 5. As shown in Figure 5, the AP sample only has the "mantou peak" of the glass phase, and no crystal diffraction peak. However, after heat treatment, a series of quantum dot glasses showed a crystal diffraction peak at 570°C, and the diffraction peak matched the diffraction peak of NaCl crystals, indicating that NaCl crystals were precipitated in the glass. As the heat treatment temperature increases, the size of the NaCl crystals gradually grows, and the corresponding diffraction peak intensity gradually increases.

[0184] Absorption spectra were tested on the original sample provided in Example 2 and a series of quantum dot glasses. As shown in Figure 6, the AP sample exhibits no absorption peak. However, as the heat treatment temperature increases, the absorption peak of the quantum dot glass gradually shifts toward longer wavelengths. This indicates that PbS / NaCl core-shell quantum dots are precipitated in the glass sample prepared in Example 2, and the size of the PbS quantum dots increases with increasing heat treatment temperature.

[0185] Luminescence spectra of a series of quantum dot glasses prepared in Example 2 were tested at an excitation wavelength of 800 nm. As shown in Figure 7, the AP sample exhibits no fluorescence peak. However, as the heat treatment temperature increases, the fluorescence peak of the quantum dot glass gradually shifts toward longer wavelengths. This indicates that PbS / NaBr core-shell quantum dots are precipitated in the glass samples prepared in Example 2, and the size of the PbS quantum dots increases with increasing heat treatment temperature and time.

[0186] Transmission electron microscopy (TEM) scanning tests were performed on the quantum dot glass provided in Example 2. The heat treatment temperature and time for the quantum dot glass were 590°C / 10 hours, respectively. As shown in Figure 8 , NaCl crystals semi-encapsulate the PbS quantum dots. The grains with a size of approximately 25 nm are NaCl crystals, while the grains with a size of approximately 5 nm are PbS quantum dots. The NaCl crystals and PbS quantum dots form a semi-encapsulated core-shell structure.

[0187] The luminous efficiency of the quantum dot glass provided in Example 2 was tested. The heat treatment temperature and time of the quantum dot glass were 570°C / 10 hours, respectively, and the excitation wavelength was 650nm. The test results are shown in Figure 9, where the solid black triangles in Figure 9 represent the luminescence spectrum of the 650nm excitation light source, and the hollow circles represent the luminescence spectrum of the quantum dot glass. As shown in Figure 9, under the excitation of the 650nm wavelength light source, the luminous efficiency of the quantum dot glass reached 78%. This is because the alkali metal halide crystals effectively passivate the surface defects of the PbS quantum dots, thereby effectively improving the luminous efficiency of the quantum dots.

[0188] Example 3

[0189] Quantum dot glass was prepared in Example 3, and was prepared by the following method: providing uniformly mixed raw materials for preparing quantum dot glass, wherein the elemental composition of the raw materials for preparing quantum dot glass conforms to the elemental composition of the raw materials for preparing quantum dot glass in Example 3 in Table 1. The raw materials for preparing quantum dot glass were placed in a crucible for melting treatment, the melting temperature was 1350°C, and the melting time was 60 minutes to obtain molten glass liquid. After the molten glass liquid was cooled, a glass precursor was formed, which was transferred to an annealing furnace for annealing treatment, the annealing temperature was 350°C, and the annealing time was 5 hours to obtain a yellow transparent glass intermediate. The glass intermediate was transferred to a heat treatment furnace for heat treatment, and the heat treatment was carried out at 570°C-590°C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on its surface in the glass matrix to obtain a series of quantum dot glasses.

[0190] The series of quantum dot glasses prepared in Example 3 include: PbS quantum dots and NaI crystals located on the outer surface of the PbS quantum dots. X-ray diffraction testing shows that no particularly obvious NaI crystal diffraction peaks are found in the quantum dot glass of Example 3. This may be due to the low content or small particle size of NaI crystals. At this time, the surface defect passivation process of the PbS quantum dots is mainly that the NaI crystals are dispersed and distributed on the outer surface of the PbS quantum dots, and the iodine atoms are bonded and passivated with the lead atoms.

[0191] The following tests were performed on a series of quantum dot glasses prepared in Example 3, wherein the heat treatment temperatures of these quantum dot glasses were 570°C, 580°C, and 590°C, respectively, and the heat treatment time was 10 hours, so the numbers of these quantum dot glasses were defined as: 57010, 58010, and 59010, respectively.

[0192] The glass intermediate involved in Example 3 is called the original sample (AP for short). The original sample provided in Example 3 and a series of quantum dot glasses were subjected to X-ray diffraction treatment. The obtained X-ray diffraction patterns are shown in Figure 10. As shown in Figure 10, the AP sample only has the "mantou peak" of the glass phase and no crystal diffraction peak. However, after heat treatment, a series of quantum dot glasses showed a crystal diffraction peak at 570°C, and the diffraction peak matched the diffraction peak of PbS crystal, indicating that PbS crystals were precipitated in the glass. As the heat treatment temperature increases, the size of the PbS crystals gradually grows, and the corresponding diffraction peak intensity gradually increases.

[0193] Absorption spectra were tested on the original sample provided in Example 3 and a series of quantum dot glasses. As shown in Figure 11, no absorption peak existed in the AP sample. As the heat treatment temperature increased, the absorption peak of the quantum dot glass gradually shifted to the long-wave band, indicating that PbS quantum dots were precipitated in the glass sample prepared in Example 3, and the size of the PbS quantum dots gradually increased with the increase of the heat treatment temperature.

[0194] Luminescence spectra of a series of quantum dot glasses prepared in Example 3 were tested at an excitation wavelength of 800 nm. As shown in Figure 12 , the fluorescence peak of the quantum dot glasses gradually shifted toward longer wavelengths as the heat treatment temperature increased. This indicates that PbS quantum dots were precipitated in the glass samples prepared in Example 3, and that the size of the PbS quantum dots gradually increased with increasing heat treatment temperature and time.

[0195] The luminous efficiency of a quantum dot glass provided in Example 3 was tested. The heat treatment temperature and time of the quantum dot glass were 590°C / 10 hours, respectively, and the excitation wavelength was 650nm. The test results are shown in Figure 13, where the solid black squares in Figure 13 refer to the luminescence spectrum of the 650nm excitation light source, and the hollow circles are the luminescence spectrum of the quantum dot glass. Combined with the luminescence spectrum shown in Figure 13, it can be seen that under the excitation of a 650nm wavelength light source, the luminescence efficiency of the quantum dot glass is as high as 70%. This is because the alkali metal halide crystals effectively passivate the surface defects of the PbS quantum dots, thereby effectively improving the luminescence efficiency of the quantum dots.

[0196] Example 4

[0197] Quantum dot glass was prepared in Example 4, which was prepared by the following method: providing uniformly mixed raw materials for preparing quantum dot glass, the elemental composition of the raw materials for preparing quantum dot glass conforming to the elemental composition of the raw materials for preparing quantum dot glass in Example 4 in Table 1. The raw materials for preparing quantum dot glass were placed in a crucible for melting treatment, the melting temperature was 1300°C, and the melting time was 60 minutes to obtain molten glass liquid. After the molten glass liquid was cooled, a glass precursor was formed, which was transferred to an annealing furnace for annealing treatment, the annealing temperature was 350°C, and the annealing time was 5 hours to obtain a yellow transparent glass intermediate. The glass intermediate was transferred to a heat treatment furnace for heat treatment, and the heat treatment was carried out at 570°C-600°C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on its surface in the glass matrix to obtain a series of quantum dot glasses.

[0198] The series of quantum dot glasses prepared in Example 4 have PbS quantum dots in their glass matrices, as well as shell-shaped NaCl crystals and dispersed NaI crystals located on the outer surfaces of the PbS quantum dots.

[0199] The following tests were performed on a series of quantum dot glasses prepared in Example 4, wherein the heat treatment temperatures of these quantum dot glasses were 570°C, 580°C, 590°C, and 600°C, respectively, and the heat treatment time was 10 hours, thereby defining the numbers of these quantum dot glasses as: 57010, 58010, and 59010, respectively.

[0200] The glass intermediate involved in Example 4 is called the original sample (AP for short). The original sample provided in Example 4 and a series of quantum dot glasses were subjected to absorption spectrum tests. As shown in Figure 14, there is no absorption peak in the AP sample. As the heat treatment temperature increases, the absorption peak of the quantum dot glass gradually shifts to the long-wave band, which indicates that PbS quantum dots are precipitated in the glass sample prepared in Example 4, and the size of the PbS quantum dots gradually increases with the increase of the heat treatment temperature.

[0201] Luminescence spectra of a series of quantum dot glasses provided in Example 4 were tested at an excitation wavelength of 800 nm. As shown in Figure 15 , as the heat treatment temperature increases, the fluorescence peak of the quantum dot glasses gradually shifts toward longer wavelengths. This indicates that PbS quantum dots are precipitated in the glass samples prepared in Example 4, and the size of the PbS quantum dots increases with increasing heat treatment temperature and time. In Figure 15 , quantum dot glass numbered 59010 is represented by an ▲ symbol, and quantum dot glass numbered 60010 is represented by a ▼ symbol.

[0202] The luminous efficiency of a series of quantum dot glasses provided in Example 4 was tested, and the excitation wavelength was 650nm. The test results are shown in Figure 16, where the solid black squares in Figure 16 refer to the luminescence spectrum of the 650nm excitation light source, and the hollow circles, hollow triangles, and hollow five-pointed stars are quantum dot glasses 57010, 58010, and 59010, respectively. As shown in Figure 16, under the excitation of a 650nm wavelength light source, the luminous efficiency of the quantum dot glass is as high as 70%. This is because the alkali metal halide crystals effectively passivate the surface defects of the PbS quantum dots, thereby effectively improving the luminous efficiency of the quantum dots. In addition, this also confirms that when the shell is an alkali metal halide of mixed halogen elements, it also plays a role in improving the luminous efficiency of the quantum dots.

[0203] Example 5

[0204] Quantum dot glass was prepared in Example 5, which was prepared by the following method: providing uniformly mixed raw materials for preparing quantum dot glass, the elemental composition of the raw materials for preparing quantum dot glass conforming to the elemental composition of the raw materials for preparing quantum dot glass in Example 5 in Table 1. The raw materials for preparing quantum dot glass were placed in a crucible for melting treatment, the melting temperature was 1300°C, and the melting time was 60 minutes to obtain molten glass liquid. After the molten glass liquid was cooled, a glass precursor was formed, which was transferred to an annealing furnace for annealing treatment, the annealing temperature was 350°C, and the annealing time was 5 hours to obtain a yellow transparent glass intermediate. The glass intermediate was transferred to a heat treatment furnace for heat treatment, and the heat treatment was carried out at 610°C-630°C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on its surface in the glass matrix to obtain a series of quantum dot glasses.

[0205] The series of quantum dot glasses prepared in Example 5 include: PbS quantum dots and NaI crystals located on the outer surface of the PbS quantum dots.

[0206] The following tests were performed on a series of quantum dot glasses prepared in Example 5, wherein the heat treatment temperatures of these quantum dot glasses were 610°C, 620°C, and 630°C, respectively, and the heat treatment time was 10 hours, so the numbers of these quantum dot glasses were defined as: 61010, 62010, and 63010, respectively.

[0207] Luminescence spectra of a series of quantum dot glasses prepared in Example 5 were tested at an excitation wavelength of 800 nm. As shown in Figure 17 , the fluorescence peak of the quantum dot glasses gradually shifted toward longer wavelengths as the heat treatment temperature increased. This indicates that PbS quantum dots were precipitated in the glass samples prepared in Example 5, and that the size of the PbS quantum dots gradually increased with increasing heat treatment temperature.

[0208] The luminous efficiency of the quantum dot glass provided in Example 5 was tested. The heat treatment temperature and time of the quantum dot glass were 620° C. / 10 hours respectively. The test results showed that the absolute quantum efficiency of the quantum dot glass was 72%.

[0209] Example 6

[0210] Quantum dot glass was prepared in Example 6, which was prepared by the following method: providing uniformly mixed raw materials for preparing quantum dot glass, the elemental composition of the raw materials for preparing quantum dot glass conforming to the elemental composition of the raw materials for preparing quantum dot glass in Example 6 in Table 1. The raw materials for preparing quantum dot glass were placed in a crucible for melting treatment, the melting temperature was 1280°C, and the melting time was 60 minutes to obtain molten glass liquid. After the molten glass liquid was cooled, a glass precursor was formed, which was transferred to an annealing furnace for annealing treatment, the annealing temperature was 330°C, and the annealing time was 5 hours to obtain a yellow transparent glass intermediate. The glass intermediate was transferred to a heat treatment furnace for heat treatment, and the heat treatment was carried out at 570°C-650°C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on its surface in the glass matrix to obtain a series of quantum dot glasses.

[0211] The series of quantum dot glasses prepared in Example 6 have PbS quantum dots in their glass matrices, as well as shell-shaped NaCl crystals, shell-shaped KCl crystals, and dispersed NaI crystals located on the outer surfaces of the PbS quantum dots.

[0212] The following tests were performed on a series of quantum dot glasses prepared in Example 6, wherein the heat treatment temperatures of these quantum dot glasses were 570°C, 580°C, 590°C, 600°C, 620°C, 640°C, and 650°C, respectively, and the heat treatment time was 10 hours, so the numbers of these quantum dot glasses were defined as: 57010, 58010, 59010, 60010, 62010, 64010, and 65010, respectively.

[0213] Luminescence spectra of a series of quantum dot glasses provided in Example 6 were tested at an excitation wavelength of 800 nm. As shown in Figure 18 , the fluorescence peak of the quantum dot glasses gradually shifted toward longer wavelengths as the heat treatment temperature increased. This indicates that PbS quantum dots were precipitated in the glass samples prepared in Example 6, and that the size of the PbS quantum dots gradually increased with increasing heat treatment temperature. In Figure 18 , the quantum dot glass numbered 62010 is represented by a triangle, the quantum dot glass numbered 64010 by a circle, and the quantum dot glass numbered 65010 by a diamond.

[0214] The luminous efficiency of the quantum dot glass provided in Example 6 was tested. The heat treatment temperature and time of the quantum dot glass were 640° C. / 10 hours respectively. The test results showed that the absolute quantum efficiency of the quantum dot glass was 75%.

[0215] Example 7

[0216] Quantum dot glass was prepared in Example 7 and was prepared by the following method: providing uniformly mixed raw materials for preparing quantum dot glass, wherein the elemental composition of the raw materials for preparing quantum dot glass conforms to the elemental composition of the raw materials for preparing quantum dot glass in Example 7 in Table 1. The raw materials for preparing quantum dot glass were placed in a crucible for melting treatment at a melting temperature of 1250°C and a melting time of 60 minutes to obtain a molten glass liquid. After the molten glass liquid was cooled, a glass precursor was formed, which was transferred to an annealing furnace for annealing treatment at an annealing temperature of 320°C and an annealing time of 5 hours to obtain a yellow transparent glass intermediate. The glass intermediate was transferred to a heat treatment furnace for heat treatment at 570°C-600°C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on its surface in the glass matrix to obtain a series of quantum dot glasses.

[0217] The series of quantum dot glasses prepared in Example 7 have PbS quantum dots in the glass matrix, as well as shell-shaped LiCl crystals and dispersed LiBr crystals located on the outer surface of the PbS quantum dots.

[0218] The following tests were performed on a series of quantum dot glasses prepared in Example 7, wherein the heat treatment temperatures of these quantum dot glasses were 570°C, 580°C, 590°C, and 600°C, respectively, and the heat treatment time was 10 hours, thereby defining the numbers of these quantum dot glasses as: 57010, 58010, 59010, and 60010, respectively.

[0219] Luminescence spectra of a series of quantum dot glasses prepared in Example 7 were tested at an excitation wavelength of 800 nm. As shown in Figure 19 , the fluorescence peak of the quantum dot glasses gradually shifted toward longer wavelengths as the heat treatment temperature increased. This indicates that PbS quantum dots were precipitated in the glass samples prepared in Example 7, and that the size of the PbS quantum dots gradually increased with increasing heat treatment temperature.

[0220] The luminous efficiency of the quantum dot glass provided in Example 7 was tested. The heat treatment temperature and time of the quantum dot glass were 570° C. / 10 hours, respectively. The test results showed that the absolute quantum efficiency of the quantum dot glass was 70%.

[0221] Example 8

[0222] Quantum dot glass was prepared in Example 8, which was prepared by the following method: providing uniformly mixed raw materials for preparing quantum dot glass, the elemental composition of the raw materials for preparing quantum dot glass conforming to the elemental composition of the raw materials for preparing quantum dot glass in Example 8 in Table 1. The raw materials for preparing quantum dot glass were placed in a crucible for melting treatment, the melting temperature was 1200°C, and the melting time was 60 minutes to obtain molten glass liquid. After the molten glass liquid was cooled, a glass precursor was formed, which was transferred to an annealing furnace for annealing treatment, the annealing temperature was 300°C, and the annealing time was 5 hours to obtain a yellow transparent glass intermediate. The glass intermediate was transferred to a heat treatment furnace for heat treatment, and the heat treatment was carried out at 570°C-600°C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on its surface in the glass matrix to obtain a series of quantum dot glasses.

[0223] The series of quantum dot glasses prepared in Example 8 have PbS quantum dots in their glass matrices, as well as dispersed NaCl crystals, dispersed NaBr crystals, and dispersed NaI crystals located on the outer surfaces of the PbS quantum dots.

[0224] The following tests were performed on a series of quantum dot glasses prepared in Example 8, wherein the heat treatment temperatures of these quantum dot glasses were 570°C, 580°C, 590°C, and 600°C, respectively, and the heat treatment time was 10 hours, so the numbers of these quantum dot glasses were defined as: 57010, 58010, 59010, and 60010, respectively.

[0225] Luminescence spectra of a series of quantum dot glasses prepared in Example 8 were tested at an excitation wavelength of 800 nm. As shown in Figure 20 , the fluorescence peak of the quantum dot glasses gradually shifted toward longer wavelengths as the heat treatment temperature increased. This indicates that PbS quantum dots were precipitated in the glass samples prepared in Example 8, and that the size of the PbS quantum dots gradually increased with increasing heat treatment temperature.

[0226] The luminous efficiency of a quantum dot glass provided in Example 8 was tested. The heat treatment temperature and time of the quantum dot glass were 590° C. / 10 hours, respectively. The test results showed that the absolute quantum efficiency of the quantum dot glass was 76%.

[0227] The above description is only for the purpose of facilitating those skilled in the art to understand the technical solutions of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A quantum dot glass raw material, wherein: The quantum dot glass raw material includes the following elements in molar percentage: Si element: 4.96% to 21.05%; B element: 3.51% to 19.85%; Al element: 0% to 7.44%; G element: 0.29% to 3.16%; Pb element: 0.03% to 0.5%; O element: 49.15% to 60.31%; N element: 1.62% to 8.77%; M element: 5.28% to 18.49%; X element: 0.7% to 8.16%; Wherein, the G element is sulfur element S, selenium element Se or tellurium element Te; The N element is an alkaline earth metal element; M element is an alkali metal element; The X element is a halogen element.

2. The quantum dot glass raw material according to claim 1, wherein: The N element is selected from at least one of Sr, Ca and Ba.

3. The quantum dot glass raw material according to claim 1, wherein: The M element is selected from at least one of Na element, K element and Li element.

4. The quantum dot glass raw material according to claim 1, wherein: The X element is selected from at least one of Cl element, Br element and I element.

5. The quantum dot glass raw material according to any one of claims 1 to 4, wherein: The Si element exists in the form of silicon oxide; The B element exists in the form of boron oxide; The Al element exists in the form of aluminum oxide; The G element is present in at least one of the MG form and the G elemental form; The Pb element is present in at least one of the form of lead oxide and the form of single lead; The alkaline earth metal element N is present in at least one of the form of an alkaline earth metal carbonate compound and an alkaline earth metal halide; The alkali metal element M is present in at least one of the form of an alkali metal carbonate, an alkali metal sulfide and an alkali metal halide; The halogen element X is present in at least one of an alkaline earth metal halide form and an alkali metal halide form.

6. The quantum dot glass raw material according to claim 5, wherein: The G element is sulfur element S, and the sulfur element S exists in at least one of the form of alkali metal sulfide and the form of sulfur element.

7. A method for preparing quantum dot glass, wherein: The method for preparing the quantum dot glass comprises: Providing raw materials for preparing quantum dot glass, wherein the element composition of the raw materials for preparing quantum dot glass conforms to the element composition of the raw materials for preparing quantum dot glass according to any one of claims 1 to 6; The raw materials for preparing the quantum dot glass are melted, and the molten glass liquid is poured into a special mold for cooling and forming to obtain a glass precursor; Annealing the glass precursor to obtain a glass intermediate; The glass intermediate is heat-treated to precipitate quantum dots in the glass matrix, thereby obtaining the quantum dot glass.

8. The method for preparing quantum dot glass according to claim 7, wherein: The temperature of the melting treatment is 1200°C to 1500°C, and the time of the melting treatment is 30 minutes to 60 minutes; The temperature of the annealing treatment is 300° C. to 400° C., and the time of the annealing treatment is 3 hours to 8 hours.

9. The method for preparing quantum dot glass according to claim 7, wherein: The temperature of the heat treatment is 540° C. to 650° C., and the time of the heat treatment is 1 hour to 48 hours.

10. A method for preparing a quantum dot optical fiber core, wherein: The method for preparing the quantum dot optical fiber core comprises: Providing raw materials for preparing quantum dot glass, wherein the element composition of the raw materials for preparing quantum dot glass conforms to the element composition of the raw materials for preparing quantum dot glass according to any one of claims 1 to 6; The raw materials for preparing the quantum dot glass are melted, and the molten glass liquid is poured into a special mold for cooling and forming to obtain a glass precursor; Performing optical fiber drawing processing on the glass precursor to obtain a first optical fiber core preform; Annealing the first optical fiber preform to obtain a second optical fiber core preform; The second optical fiber core preform is heat-treated to precipitate quantum dots in the glass matrix to obtain the quantum dot optical fiber core.

11. The method for preparing a quantum dot optical fiber core according to claim 10, wherein: The temperature of the melting treatment is 1200°C to 1500°C, and the time of the melting treatment is 30 minutes to 60 minutes; The annealing temperature is 300°C to 400°C, and the annealing time is 3 hours to 8 hours; The temperature of the heat treatment is 540° C. to 650° C., and the time of the heat treatment is 1 hour to 48 hours.

12. A quantum dot glass, wherein: The quantum dot glass is prepared by using the quantum dot glass raw material described in any one of claims 1 to 6, or by using the method for preparing the quantum dot glass described in any one of claims 7 to 9; The quantum dot glass includes a glass matrix and a quantum dot system located in the glass matrix, the quantum dot system includes PbG quantum dots and alkali metal halide crystals located on the outer surface of the PbG quantum dots, the alkali metal halide crystals are composed of elements M and elements X, and the G element is sulfur element S, selenium element Se or tellurium element Te.

13. The quantum dot glass according to claim 12, wherein: The alkali metal halide crystals exist in at least one of a first form and a second form; The first form is a shell form, so that the alkali metal halide crystals are coated on at least a portion of the outer surface of the PbG quantum dots; The second form is a dispersed crystal form, so that the alkali metal halide crystals are dispersedly distributed on the outer surface of the PbG quantum dots.

14. A quantum dot optical fiber, wherein: The quantum dot optical fiber comprises a quantum dot optical fiber core, and the quantum dot optical fiber core is prepared by using the quantum dot glass raw material according to any one of claims 1 to 6, or by using the preparation method of the quantum dot optical fiber core according to any one of claims 10 to 11; The quantum dot optical fiber core includes a glass matrix and a quantum dot system located in the glass matrix, the quantum dot system includes PbG quantum dots and alkali metal halide crystals located on the outer surface of the PbG quantum dots, the alkali metal halide crystals are composed of elements M and elements X, and the G element is sulfur element S, selenium element Se or tellurium element Te.

15. The quantum dot optical fiber according to claim 14, wherein: The alkali metal halide crystals exist in at least one of a first form and a second form; The first form is a shell form, so that the alkali metal halide crystals are coated on at least a portion of the outer surface of the PbG quantum dots; The second form is a dispersed crystal form, so that the alkali metal halide crystals are dispersedly distributed on the outer surface of the PbG quantum dots.

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