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

Abstract

The invention discloses a quantum dot glass raw material, quantum dot glass, a quantum dot optical fiber core and a preparation method, and belongs to the technical field of optics. Raw materials of the quantum dot glass comprise the following elements by mole percent: 4.96%-21.05% of Si; the content of B is 3.51%-19.85%; 0%-7.44% of Al; 0.29% to 3.16% of G; 0.03% to 0.5% of Pb; the content of O is 49.15%-60.31%; 1.62% to 8.77% of N; 5.28% to 18.49% of M; and X is 0.7%-8.16%. The G element is S, Se or 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. The halogen elements and the alkali metal elements are matched to form alkali metal halide crystals which are located on the surfaces of the PbG quantum dots, so that the surfaces of the PbG quantum dots are passivated, and the luminous efficiency of the PbG quantum dots is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of optics, and particularly to quantum dot glass raw materials, quantum dot glass, quantum dot optical fiber cores, and preparation methods thereof. Background Art

[0002] IV-VI group semiconductor quantum dots, such as PbS, PbSe, etc., have advantages such as small bandgap energy, large exciton Bohr radius, and fluorescence wavelength that can be adjusted below 3 μm and 4.4 μm, making them widely used in many fields.

[0003] The preparation methods of quantum dots include chemical synthesis method, sol-gel method, melting method, etc. Among them, the melting method grows quantum dots in a glass matrix through a heat treatment process, which can not only prevent the aggregation of quantum dots, but also facilitate the improvement of the chemical stability, thermal stability, and mechanical stability of quantum dots.

[0004] However, in related technologies, the luminescence efficiency of quantum dots is low, and the stability needs to be improved.

[0005] Disclosure

[0006] On the one hand, a quantum dot glass raw material is provided. The quantum dot glass raw material includes the following elements in mole percentages: Si element: 4.96% - 21.05%; B element: 3.51% - 19.85%; Al element: 0% - 7.44%; G element: 0.29% - 3.16%; Pb element: 0.03% - 0.5%; O element: 49.15% - 60.31%; N element: 1.62% - 8.77%; M element: 5.28% - 18.49%; X element: 0.7% - 8.16%.

[0007] 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; the X element is a halogen element.

[0008] The quantum dot glass raw material provided by 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.

[0009] 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 above elements in specific molar percentages, the prepared quantum dot glass products have at least the following advantages: PbS quantum dots are formed in situ in the glass matrix, which not only facilitates the uniform dispersion of PbS quantum dots but also enhances the stability of PbS quantum dots. By adding a certain amount of halogen elements and alkali metal elements to cooperate with each other, alkali metal halide crystals (abbreviated as MX crystals) can be formed. The MX crystals exist on the surface of PbS quantum dots and are connected to each other through lead halide bonds to achieve the passivation of the surface of PbS quantum dots, thereby effectively reducing the capture of carriers by surface defects of PbS quantum dots and improving the luminescence efficiency of PbS quantum dots. Moreover, when the content of MX crystals is relatively large and reaches the target threshold, it can coat at least a part of the outer surface of PbS quantum dots in the form of a shell layer. This not only helps to improve the surface passivation effect on PbS quantum dots but also enables PbS quantum dots to be protected by both the shell layer and the glass matrix simultaneously, further enhancing the mechanical stability, thermal stability, and chemical stability of PbS quantum dots. In addition, alkali metal halide crystals are also beneficial for reducing the melting temperature and viscosity of the glass melt and improving the uniformity of the glass matrix.

[0010] In some possible implementation manners, the N element is selected from at least one of Sr element, Ca element, and Ba element.

[0011] In some possible implementation manners, the M element is selected from at least one of Na element, K element, and Li element.

[0012] In some possible implementation manners, the X element is selected from at least one of Cl element, Br element, and I element.

[0013] Cl element, Br element, and I element are selected as the X element, and they are compounded with the alkali metal element M to form alkali metal halide crystals and combine to the outer surface of PbS quantum dots, thereby passivating the surface defects of PbS quantum dots and improving the luminescence efficiency.

[0014] In some possible implementation manners, the Si element exists in the form of silicon oxide;

[0015] The B element exists in the form of boron oxide;

[0016] The Al element exists in the form of aluminum oxide;

[0017] The G element exists in at least one of the form of MG and G elemental form;

[0018] The Pb element exists in at least one of the form of lead oxide and lead elemental form;

[0019] The alkaline earth metal element N exists in at least one of the forms of alkaline earth metal carbonate compounds and alkaline earth metal halides;

[0020] The alkali metal element M exists in at least one of the forms of alkali metal carbonate compounds, alkali metal sulfide compounds and alkali metal halides;

[0021] The halogen element X exists in at least one of the forms of alkaline earth metal halides and alkali metal halides.

[0022] In some possible implementation manners, the element G is the sulfur element S, and the sulfur element S exists in at least one of the forms of alkali metal sulfide compounds and sulfur in elemental form.

[0023] On the other hand, a method for preparing a quantum dot glass is provided, and the method for preparing the quantum dot glass includes:

[0024] Providing raw materials for preparing the quantum dot glass, wherein the elemental composition of the raw materials for preparing the quantum dot glass conforms to the elemental composition in any one of the above-mentioned quantum dot glass raw materials;

[0025] Performing a melting treatment on the raw materials for preparing the quantum dot glass to obtain a molten glass liquid;

[0026] Performing an annealing treatment on the molten glass liquid to obtain a glass intermediate;

[0027] Performing a heat treatment on the glass intermediate so as to precipitate quantum dots in the glass matrix to obtain the quantum dot glass.

[0028] In the method for preparing a quantum dot glass provided by the embodiments of the present disclosure, by sequentially performing a melting treatment, an annealing treatment and a heat treatment on the raw materials for preparing the quantum dot glass, uniformly dispersed PbG quantum dots (such as PbS quantum dots) can be precipitated in the glass matrix, and the quantum dot glass can be prepared. This method is simple and convenient to operate, and the prepared quantum dot glass has excellent luminous efficiency, mechanical stability, thermal stability and chemical stability.

[0029] In some possible implementation manners, 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;

[0030] 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.

[0031] In some possible implementation manners, 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.

[0032] Through the above heat treatment process, not only can PbG quantum dots precipitate in the glass matrix, but also, on the basis of the PbG quantum dots as crystal nuclei, the alkali metal halide crystal MX gradually precipitates.

[0033] During the heat treatment process, by adjusting the heat treatment temperature and heat treatment time, 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 crystal MX, can be adjusted.

[0034] On the other hand, a method for preparing a quantum dot optical fiber core is provided. The method for preparing the quantum dot optical fiber core includes:

[0035] Providing raw materials for preparing quantum dot glass, and the elemental composition of the raw materials for preparing the quantum dot glass conforms to the elemental composition in any of the above-mentioned quantum dot glass raw materials;

[0036] Performing melting treatment on the raw materials for preparing the quantum dot glass to obtain a molten glass liquid;

[0037] Performing optical fiber drawing treatment on the molten glass liquid to obtain a first optical fiber core preform;

[0038] Performing annealing treatment on the first optical fiber preform to obtain a second optical fiber core preform;

[0039] Performing heat treatment on the second optical fiber core preform to precipitate quantum dots in the glass matrix, thereby obtaining the quantum dot optical fiber core.

[0040] In some possible implementation manners, 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;

[0041] 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;

[0042] 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.

[0043] On the other hand, a quantum dot glass is provided. The quantum dot glass is prepared by using the above-mentioned quantum dot glass raw materials or by using the above-mentioned method for preparing quantum dot glass;

[0044] 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 element M and element X. The G element is sulfur element S, selenium element Se or tellurium element Te. Correspondingly, the PbG quantum dots are PbS quantum dots, PbSe quantum dots or PbTe quantum dots.

[0045] The quantum dot glass provided by the embodiments of the present disclosure has at least the following advantages: PbG quantum dots are in-situ formed in the glass matrix, which is not only beneficial to the uniform dispersion of PbG quantum dots, but also beneficial to improving the stability of PbG quantum dots. By adding a certain amount of halogen elements and alkali metal elements to cooperate with each other, alkali metal halide crystals (abbreviated as MX crystals) can be formed. The MX crystals exist on the surface of the PbG quantum dots and are connected to each other through lead halide bonds to achieve the passivation of the surface of the PbG quantum dots, thereby effectively reducing the capture of carriers by the surface defects of the PbG quantum dots and improving the luminescence efficiency of the PbG quantum dots. Moreover, when the content of the MX crystals is relatively large and reaches the target threshold, it can coat at least a part of the outer surface of the PbG quantum dots in the form of a shell layer, which is not only beneficial to improving the surface passivation effect of the PbG quantum dots, but also enables the PbG quantum dots to be protected by both the shell layer and the glass matrix at the same time, 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.

[0046] In some possible implementation manners, the alkali metal halide crystals exist in at least one of a first form and a second form;

[0047] The first form is a shell layer form, such that the alkali metal halide crystals coat at least a part of the outer surface of the PbG quantum dots;

[0048] The second form is a dispersed crystal form, such that the alkali metal halide crystals are distributed in a dispersed manner on the outer surface of the PbG quantum dots.

[0049] For the shell layer form, one example is that the alkali metal halide crystals coat the PbG quantum dots in a full-wrap manner, and another example is that the alkali metal halide crystals coat the PbG quantum dots in a semi-wrap manner. The alkali metal halide crystals can exist in at least one of the full-wrap and semi-wrap manners.

[0050] On the other hand, a quantum dot optical fiber is provided. The quantum dot optical fiber includes a quantum dot optical fiber core, and the quantum dot optical fiber core uses the above-mentioned quantum dot glass raw materials or is prepared by using the preparation method of the above-mentioned quantum dot optical fiber core;

[0051] 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 element M and element X, and the G element is sulfur element S, selenium element Se or tellurium element Te.

[0052] In some possible implementations, the alkali metal halide crystal exists in at least one of a first form and a second form;

[0053] The first form is a shell form such that the alkali metal halide crystal coats at least a portion of the outer surface of the PbG quantum dots;

[0054] 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. Description of the Drawings

[0055] Figure 1 X-ray diffraction patterns of the original sample provided for Example 1 and a series of quantum dot glasses;

[0056] Figure 2 Absorption spectra of the original sample provided for Example 1 and a series of quantum dot glasses;

[0057] Figure 3 Emission spectra of a series of quantum dot glasses provided for Example 1;

[0058] Figure 4 Emission efficiency test spectra of the quantum dot glass numbered 58010 provided for Example 1;

[0059] Figure 5 X-ray diffraction patterns of the original sample provided for Example 2 and a series of quantum dot glasses;

[0060] Figure 6 Absorption spectra of the original sample provided for Example 6 and a series of quantum dot glasses;

[0061] Figure 7 Emission spectra of a series of quantum dot glasses provided for Example 2;

[0062] Figure 8 Transmission electron microscope images of the quantum dot glass numbered 59010 provided for Example 2;

[0063] Figure 9 Emission efficiency test spectra of the quantum dot glass numbered 57010 provided for Example 2;

[0064] Figure 10 X-ray diffraction patterns of the original sample provided for Example 3 and a series of quantum dot glasses;

[0065] Figure 11 Absorption spectra of the original sample provided for Example 3 and a series of quantum dot glasses;

[0066] Figure 12 Emission spectra of a series of quantum dot glasses provided for Example 3;

[0067] Figure 13 The luminescence efficiency test spectrogram of the quantum dot glass numbered 59010 provided for Example 3;

[0068] Figure 14 The absorption spectrograms of the original sample and a series of quantum dot glasses provided for Example 4;

[0069] Figure 15 The luminescence spectrograms of a series of quantum dot glasses provided for Example 4;

[0070] Figure 16 The luminescence efficiency test spectrograms of the quantum dot glasses numbered 57010, 58010, and 59010 provided for Example 4;

[0071] Figure 17 The luminescence spectrograms of a series of quantum dot glasses provided for Example 5;

[0072] Figure 18 The luminescence spectrograms of a series of quantum dot glasses provided for Example 6;

[0073] Figure 19 The luminescence spectrograms of a series of quantum dot glasses provided for Example 7;

[0074] Figure 20 The luminescence spectrograms of a series of quantum dot glasses provided for Example 8;

[0075] Figure 21 The structural layout diagram of an exemplary amplifier provided for the embodiments of the present disclosure.

[0076] Among them, Figure 1 , Figure 5 , Figure 10 In the X-ray diffraction pattern shown, the abscissa Two theta (degree) refers to the 2θ diffraction angle, that is, the included angle between the extension line of the incident X-ray and the reflected X-ray; the ordinate Intensity (a.u.) refers to the intensity, that is, the number of photons collected.

[0077] Figure 2 , Figure 6 , Figure 11 , Figure 14 In the absorption spectrogram shown, the abscissa Wavelength (nm) refers to the wavelength, and the ordinate Absorption coefficient (cm -1 ) refers to the absorption coefficient, representing the absorption of light per unit length in the medium.

[0078] Figure 3 , Figure 7 ,Figure 12 , Figure 15 , Figure 17 , Figure 18 , Figure 19 , Figure 20 In the emission spectrum shown in Figure 20 , the abscissa Wavelength (nm) refers to the wavelength, and the ordinate PL intensity (a.u.) refers to the photoexcited luminescence intensity.

[0079] Figure 4 , Figure 9 , Figure 13 , Figure 16 In the luminous efficiency curve shown in Figure 16 , the abscissa Wavelength (nm) refers to the wavelength, and the ordinate Intensity (a.u.) refers to the intensity. Detailed implementation mode

[0080] For PbS quantum dots, their preparation methods include chemical synthesis method, sol-gel method, melting method, etc. For PbS colloidal quantum dots synthesized by chemical method, the surface modification of the quantum dots is simple and the operability is high. However, the quantum dots dispersed in the solution are prone to agglomeration, photooxidation, and have poor thermal stability, which limits their applications. The melting method grows quantum dots in a glass matrix through a heat treatment process, which can not only prevent the agglomeration of quantum dots, but also help improve the chemical stability, thermal stability, and mechanical stability of quantum dots.

[0081] However, due to the small size and large specific surface area of quantum dots, there are many surface defects, such as many dangling bonds, resulting in low luminous efficiency. It can be seen that it is very necessary to passivate the surface defects of quantum dots.

[0082] Compared with chemically synthesized PbS quantum dots, for quantum dot glasses (also known as quantum dot-dispersed glasses) synthesized by the melting method, since the PbS quantum dots are coated by the glass matrix, after the synthesis of PbS quantum dots, it is impossible to passivate the surface defects of PbS quantum dots by means of surface ligands, etc., resulting in serious surface defects of PbS quantum dots. Photo-traps generate electrons and vacancies, seriously reducing the luminous efficiency of PbS quantum dots and limiting their applications.

[0083] In view of the technical problems existing in the related art, embodiments of the present disclosure provide a quantum dot glass raw material, which includes the following elements in mole percentages: Si element: 4.96% - 21.05%; B element: 3.51% - 19.85%; Al element: 0% - 7.44%; G element: 0.29% - 3.16%; Pb element: 0.03% - 0.5%; O element: 49.15% - 60.31%; N element: 1.62% - 8.77%; M element: 5.28% - 18.49%; X element: 0.7% - 8.16%. 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; the X element is a halogen element.

[0084] The quantum dot glass raw material provided by the embodiments of the present disclosure can be used to prepare a quantum dot glass containing PbG quantum dots, and the PbG quantum dots can be PbS quantum dots, PbSe quantum dots or PbTe quantum dots. That is to say, when the G element is sulfur element S, the quantum dot glass raw material is used to prepare a quantum dot glass containing PbS quantum dots; when the G element is selenium element Se, the quantum dot glass raw material is used to prepare a quantum dot glass containing PbSe quantum dots; when the G element is tellurium element Te, the quantum dot glass raw material is used to prepare a quantum dot glass containing PbTe quantum dots.

[0085] The quantum dot glass raw material provided by the embodiments of the present disclosure can be used to prepare a quantum dot glass product. Based on the synergistic effect of the above-mentioned various elements in specific mole percentages, the prepared quantum dot glass product has at least the following advantages: The PbG quantum dots are formed in situ in the glass matrix, which is not only beneficial to the uniform dispersion of the PbG quantum dots, but also beneficial to improving the stability of the PbG quantum dots. By adding a certain amount of halogen element and cooperating with the alkali metal element, an alkali metal halide crystal (abbreviated as MX crystal) can be formed. The MX crystal exists on the surface of the PbG quantum dots and the two are connected by a lead halide bond to achieve the passivation of the surface of the PbG quantum dots, thereby effectively reducing the capture of carriers by the surface defects of the PbG quantum dots and improving the luminescence efficiency of the PbG quantum dots. Moreover, when the content of the MX crystal is relatively large and reaches the target threshold, it can coat at least a part of the outer surface of the PbG quantum dots in the form of a shell, which is not only beneficial to improving the surface passivation effect of the PbG quantum dots, but also enables the PbG quantum dots to be protected by both the shell and the glass matrix at the same time, further improving the mechanical stability, thermal stability and chemical stability of the PbG quantum dots. In addition, the alkali metal halide crystal is also beneficial to reducing the melting temperature and viscosity of the glass melt and improving the uniformity of the glass matrix.

[0086] Taking the G element as an example of sulfur element S, PbS quantum dots are in-situ formed in the glass matrix, which not only facilitates the uniform dispersion of PbS quantum dots, but also helps to improve the thermal stability, chemical stability and mechanical stability of PbS quantum dots. By adding a certain amount of halogen elements and alkali metal elements to cooperate to form alkali metal halide crystals, which exist on the surface of PbG quantum dots and are connected by halogen-lead bonds to achieve the passivation of the surface of PbS quantum dots, thereby effectively reducing the capture of carriers by surface defects of PbS quantum dots and improving the luminescence efficiency of PbS quantum dots.

[0087] In some examples, in the quantum dot glass raw materials provided by the embodiments of the present disclosure, the sum of the molar percentages of Si element, B element, Al element, G element, Pb element, O element, N element, M element, and X element is 100%.

[0088] Combined with the molar percentages of the various elements in the quantum dot glass raw materials involved above, the following gives exemplary illustrations of some applicable molar percentages of these elements respectively.

[0089] Exemplarily, 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.

[0090] Exemplarily, the molar percentage of B element 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.

[0091] Exemplarily, 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.

[0092] Exemplarily, 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.

[0093] In some examples, the G element is the S element. Considering that the S element is prone to volatilization, during application, the molar percentage of the S element is greater than that of the Pb element. For example, the ratio of the molar percentage of the sulfur element S to that of the Pb element is 2 - 20:1.

[0094] Exemplarily, the molar percentage of the Pb element includes 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%, 0.3%, 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.

[0095] Exemplarily, the molar percentages of alkaline earth metal N element include but are 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.

[0096] Exemplarily, the molar percentages of alkali metal element M include but are 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%, 12.8%, 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.

[0097] Exemplarily, the molar percentage of the halogen element X includes 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.

[0098] In the embodiments of the present disclosure, the alkaline earth metal element N is selected from at least one of Sr element, Ca element, and Ba element. That is, the alkaline earth metal element N can be any one of them, or any two of them, or all three can be used simultaneously. Selecting Sr element, Ca element, and Ba element as the alkaline earth metal element N, which exists in the form of a glass network intermediate in the quantum dot glass product, can improve the thermal stability and chemical stability of the quantum dot glass product.

[0099] The alkali metal element M is selected from at least one of Na element, K element, and Li element. That is, the alkali metal element M can be any one of them, or any two of them, or all three can be used simultaneously.

[0100] Selecting Na element, K element, and Li element 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. In this way, a part of the alkali metal element M is compounded with the halogen element X 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 luminescence efficiency. And another part of the alkali metal element M exists in the form of a glass network intermediate in the quantum dot glass product and also acts as a flux.

[0101] The halogen element X is selected from at least one of Cl element, Br element, and I element. That is, the halogen element X can be any one of them, or any two of them, or all three can be used simultaneously.

[0102] Cl element, Br element, and I element are selected as element X, which are compounded with alkali metal element M to form alkali metal halide crystals and combined on the outer surface of PbS quantum dots, thereby passivating the surface defects of PbS quantum dots and improving the luminescence efficiency.

[0103] 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. Among them, the first form is a shell form, such that the alkali metal halide crystals coat at least a part of the outer surface of the PbS quantum dots, and the two are connected by a lead-halide bond. The second form is a dispersed crystal form, such that the alkali metal halide crystals are dispersed on the outer surface of the PbS quantum dots, and the two are connected by a lead-halide bond. Herein, the "dispersed" involved may include a single alkali metal halide crystal being dispersed, or may include a plurality of alkali metal halide crystals agglomerating or combining into a cluster and being dispersed in a cluster form. Both of the above forms can achieve the passivation of the surface defects of PbS quantum dots.

[0104] By adjusting the content of halogen element X, the existence form of the alkali metal halide crystals in the glass matrix is adjusted. Generally, when the content of halogen element X is higher, it is easier to form a shell form. On the contrary, when the content of 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.

[0105] The quantum dot glass raw materials provided by the embodiments of the present disclosure, in which each element exists in at least one of the form of a simple substance and a compound, so as to facilitate the acquisition of the quantum dot glass raw materials, and thus facilitate the preparation of glass products. The existence forms of each element are described below by way of example.

[0106] In the preparation raw materials of the quantum dot glass, Si element exists in the form of silicon oxide. For example, it exists in the form of silicon dioxide (SiO 2 ). In the glass product, Si element combines with O element and serves as a glass former.

[0107] In the preparation raw materials of the quantum dot glass, B element exists in the form of boron oxide. For example, it exists in the form of boron oxide (B 2 O 3 ). In the glass product, B element combines with O element and serves as a glass former.

[0108] In the preparation raw materials of the quantum dot glass, Al element exists in the form of aluminum oxide. For example, it exists in the form of aluminum oxide (Al 2 O 3 ). In the glass product, Al element combines with O element and serves as a glass former.

[0109] In the raw materials for preparing quantum dot glass, the G element exists in at least one of the MG form and the G single substance form. For example, in the MG form, it can be Na2G, K 2 G, Li 2 G, etc. In glass products, the G element exists in the form of PbG quantum dots.

[0110] For example, the G element is the S element, and the S element exists in at least one of the form of alkali metal sulfide and sulfur element. For example, the alkali metal sulfide can be sodium sulfide (Na2S), potassium sulfide (K 2 S), lithium sulfide (Li 2 S) etc. In glass products, the S element exists in the form of PbS quantum dots.

[0111] In the raw materials for preparing quantum dot glass, the Pb element exists in at least one of the form of lead oxide and the form of single lead. For example, the lead oxide can be lead oxide (PbO). In the glass product, the Pb element exists in the form of PbS quantum dots.

[0112] The alkaline earth metal element N exists in at least one of the form of an alkaline earth metal carbonate compound and an alkaline earth metal halide. For example, the alkaline earth metal carbonate compound may be strontium carbonate (SrCO 3 ), calcium carbonate (CaCO 3 ), barium carbonate (BaCO 3 ) at least one of which, for example, an alkaline earth metal halide, may be strontium chloride (SrCl 2 ), strontium bromide (SrBr 2 ), strontium iodide (SrI 2 ), calcium chloride (CaCl 2 ), calcium bromide (CaBr 2 ), calcium iodide (CaI 2 ), barium chloride (BaCl 2 ), barium bromide (BaBr 2 ), barium iodide (BaI 2 ) At least one of the above. During the melting process, the C element evaporates in the form of gas. In addition, in the glass product, the alkaline earth metal element N is combined with the O element and serves as a glass intermediate.

[0113] In the raw materials for preparing quantum dot glass, the alkali metal element M exists in at least one of the forms of alkali metal carbonate, alkali metal sulfide and alkali metal halide. For example, alkali metal carbonate can be sodium carbonate (Na 2 CO 3 ), potassium carbonate (K 2 CO 3 、Lithium carbonate (Li2 CO 3 ) or at least one of them. Alkali metal sulfides are used in the preparation of PbS quantum dots. Taking alkali metal sulfides as an example, this can be sodium sulfide (Na2S), potassium sulfide (K 2 S), lithium sulfide (Li 2 S) or at least one of them. Among them, during the melting process, the C element volatilizes in the form of gas. And, in the glass product, part of the alkali metal element M is compounded with the halogen element X to form MX crystals and serves as the shell layer of the PbS quantum dots, and the remaining part of the alkali metal element serves as the glass network intermediate.

[0114] In the raw materials for the preparation of quantum dot glass, the halogen element X exists in at least one of the forms of alkaline earth metal halides and alkali metal halides. Taking alkaline earth metal halides as an example, this can be strontium chloride (SrCl 2 ), strontium bromide (SrBr 2 ), strontium iodide (SrI 2 ), calcium chloride (CaCl 2 ), calcium bromide (CaBr 2 ), calcium iodide (CaI 2 ), barium chloride (BaCl 2 ), barium bromide (BaBr 2 ), barium iodide (BaI 2 ) or at least one of them. Taking alkali metal halides as an example, this can be sodium chloride (NaCl), sodium bromide (NaBr), sodium iodide (NaI), potassium chloride (KCl), potassium bromide (KBr), potassium iodide (KI), lithium chloride (LiCl), lithium bromide (LiBr), lithium iodide (LiI) or at least one of them.

[0115] On the other hand, the embodiments of the present disclosure also provide a method for preparing quantum dot glass, and the method for preparing quantum dot glass includes the following steps:

[0116] Step S11: Provide the raw materials for the preparation of quantum dot glass, and the element composition of the raw materials for the preparation of quantum dot glass conforms to the element composition in any of the above-mentioned quantum dot glass raw materials.

[0117] Step S12: Perform melting treatment on the raw materials for the preparation of quantum dot glass, place the molten glass liquid in a mold and cool it to form a glass precursor.

[0118] Step S13: Perform annealing treatment on the glass precursor to obtain a glass intermediate.

[0119] Step S14: Perform heat treatment on the glass intermediate so as to precipitate quantum dots in the glass matrix to obtain quantum dot glass.

[0120] The method for preparing quantum dot glass provided in the embodiment of the present disclosure can prepare quantum dot glass by sequentially melting, annealing and heat treating the raw materials for preparing quantum dot glass, thereby precipitating uniformly dispersed PbG quantum dots (such as PbS quantum dots) in a glass matrix. The method is simple and convenient to operate, and the prepared quantum dot glass has excellent luminous efficiency, mechanical stability, thermal stability and chemical stability.

[0121] For 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.

[0122] As mentioned 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 simple form; the Pb element exists in at least one of the lead oxide form and the lead simple 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; the halogen element X exists in at least one of the alkaline earth metal halide form and the alkali metal halide form.

[0123] For each element, determine the existence form of each element and use it as a component in the raw material for preparing quantum dot glass. According to the molar ratio of the elements in the above-mentioned raw material for quantum dot glass, determine the ratio of each component in the raw material for preparing quantum dot glass, so as to obtain the raw material for preparing quantum dot glass.

[0124] In some examples, each component of the raw material for preparing quantum dot glass is accurately weighed according to the ratio, put into a mortar and fully ground to mix evenly, and then step S12 is performed.

[0125] For step S12, the raw materials for preparing quantum dot glass are melted, and the molten glass liquid is placed in a mold for cooling and forming to obtain a glass precursor. For example, the raw materials for preparing quantum dot glass can be placed in a closed crucible and melted to obtain molten glass liquid. Among them, PbS quantum dots are not formed in the molten glass liquid.

[0126] 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. 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.

[0127] For step S13, the glass precursor is annealed to obtain a glass intermediate, thereby eliminating residual stress, and the obtained glass intermediate is yellow and transparent.

[0128] The temperature of some applicable annealing treatments is 300°C to 400°C, which includes but is 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 time is 3 hours to 8 hours, which includes but is not limited to: 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, etc.

[0129] For step S14, the glass intermediate is heat-treated to precipitate quantum dots in the glass matrix, obtaining quantum dot glass.

[0130] Exemplarily, the temperature of the heat treatment is 540°C to 650°C, which includes but is 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.

[0131] 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.

[0132] Through the above heat treatment process, not only can PbG quantum dots precipitate in the glass matrix, but also, on the basis of PbG quantum dots as crystal nuclei, alkali metal halide crystals MX gradually precipitate, and the two cooperate to form a quantum dot system.

[0133] In some examples, the heat treatment of the glass intermediate includes: sequentially performing a first heat treatment and a second heat treatment on the glass intermediate, wherein at least one of the temperature and heat treatment time of the second heat treatment is greater than at least one of the temperature and heat treatment time of the first heat treatment.

[0134] Through the first heat treatment, it is convenient for the full precipitation of PbG quantum dots, and by increasing the temperature or extending the heat treatment time, it is convenient for the full precipitation of alkali metal halide crystals MX.

[0135] During the heat treatment process, by adjusting the heat treatment temperature and heat treatment time, the particle size and distribution density of PbG quantum dots, as well as the particle size and distribution density of alkali metal halide crystal MX, can be adjusted.

[0136] The heat treatment process is also the glass crystallization process, which includes two stages: nucleation and crystal growth. The higher the heat treatment temperature, the faster the nucleation growth rate, and the longer the heat treatment time, the larger the crystal size. Therefore, by controlling the length of the heat treatment time and the height of the heat treatment temperature, PbG quantum dots with high density and required size can be obtained accordingly.

[0137] On the other hand, the embodiments of the present disclosure also provide a method for preparing a quantum dot optical fiber core, and the method for preparing the quantum dot optical fiber core includes the following steps:

[0138] Step S21: Provide raw materials for preparing quantum dot glass, and the elemental composition of the raw materials for preparing quantum dot glass conforms to the elemental composition in any of the above-mentioned quantum dot glass raw materials.

[0139] Step S22: Perform melting treatment on the raw materials for preparing quantum dot glass, place the molten glass liquid in a mold and cool it to form a glass precursor.

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

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

[0142] Step S25: Perform heat treatment on the second optical fiber core preform, thereby precipitating 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 by the embodiments of the present disclosure can precipitate uniformly dispersed PbG quantum dots in the glass matrix and prepare quantum dot glass by successively performing melting treatment, optical fiber drawing treatment, annealing treatment, and heat treatment on the raw materials for preparing quantum dot glass. This method is simple and convenient to operate, and the prepared quantum dot optical fiber core has excellent luminous efficiency, mechanical stability, thermal stability, and chemical stability.

[0144] Exemplarily, 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; 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 steps S21, S22, S24, and S25, reference can be made to the relevant descriptions of steps S11, S12, S13, and S14 above respectively, which will not be elaborated here.

[0146] For step S23, the glass precursor is subjected to optical fiber drawing treatment to obtain a first optical fiber core preform, and the above drawing treatment can be carried out by using the existing optical fiber preform drawing technology.

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

[0148] Among them, 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 element M and element X. The G element is sulfur element S, selenium element Se or tellurium element 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: The PbG quantum dots are formed in-situ in the glass matrix, which is not only beneficial to the uniform dispersion of the PbG quantum dots, but also beneficial to improving the stability of the PbG quantum dots. By adding a certain amount of halogen elements and alkali metal elements to cooperate, alkali metal halide crystals (abbreviated as MX crystals) can be formed. The MX crystals exist on the surface of the PbG quantum dots and are connected by halogen-lead bonds to realize the passivation of the surface of the PbG quantum dots, thereby effectively reducing the capture of carriers by the surface defects of the PbG quantum dots and improving the luminescence efficiency of the PbG quantum dots. And when the content of the MX crystals is relatively large and reaches the target threshold, it can coat at least part of the outer surface of the PbG quantum dots in the form of a shell layer, which is not only beneficial to improving the surface passivation effect on the PbG quantum dots, but also enables the PbG quantum dots to be protected by both the shell layer and the glass matrix at the same time, 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 crystal exists in at least one of a first form and a second form. Among them, the first form is a shell form, such that the alkali metal halide crystal coats at least a part of the outer surface of the PbG quantum dots, and the two are connected by a lead halide bond. 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, and the two are connected by a lead halide bond. Herein, the "dispersed state" involved may include a single alkali metal halide crystal being dispersed, or may include a plurality of alkali metal halide crystals aggregating or combining into a cluster and being dispersed in a cluster form. Both of the above two forms can achieve the passivation of the surface defects of the PbG quantum dots.

[0151] For the shell form, in one example, the alkali metal halide crystal coats the PbG quantum dots in a fully wrapped manner, and in another example, the alkali metal halide crystal coats the PbG quantum dots in a semi-wrapped manner (i.e., does not completely coat the outer surface of the PbG quantum dots). The alkali metal halide crystal can exist in at least one of the fully wrapped and semi-wrapped manners.

[0152] In some examples, the quantum dots include PbG quantum dots, an MX crystal shell coated on the outer surface of the PbG quantum dots 1 and MX crystals dispersed on the outer surface of the PbG quantum dots 2 wherein the element X 1 and X 2 are different. The MX crystals are dispersed on the outer surface of the PbG quantum dots and also play a role in passivating the surface defects of the PbG quantum dots. For example, X 2 is Cl, and X 1 is Br or I. 2

[0153] The quantum dot glass provided by the embodiments of the present disclosure can adjust the particle size of the PbG quantum dots by adjusting the heat treatment process, so as to realize the regulation of the absorption and luminescence of the quantum dot glass in the wavelength range of 900 nm - 2400 nm.

[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 another aspect, embodiments of the present disclosure also provide a quantum dot optical fiber (also known as a quantum dot glass optical fiber). The quantum dot optical fiber includes a quantum dot optical fiber core, and the quantum dot optical fiber core is made of any of the above-mentioned quantum dot glass raw materials, or is prepared by using any of the above-mentioned preparation methods of the quantum dot optical fiber core. Wherein, 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 an alkali metal halide crystal located on the outer surface of the PbG quantum dots. The alkali metal halide crystal is composed of element M and element X.

[0156] The quantum dot optical fiber provided by the embodiments of the present disclosure has at least the following advantages: The PbG quantum dots are in-situ formed in the glass matrix, which is not only beneficial to the uniform dispersion of the PbG quantum dots, but also beneficial to improving the stability of the PbG quantum dots. By adding a certain amount of halogen elements and alkali metal elements to cooperate, an alkali metal halide crystal (abbreviated as MX crystal) can be formed. The MX crystal exists on the surface of the PbG quantum dots and the two are connected by a lead halide bond to realize the passivation of the surface of the PbG quantum dots, thereby effectively reducing the capture of carriers by the surface defects of the PbG quantum dots and improving the luminescence efficiency of the PbG quantum dots. And when the content of the MX crystal is relatively large and reaches the target threshold, it can coat at least part of the outer surface of the PbG quantum dots in the form of a shell, which is not only beneficial to improving the surface passivation effect of the PbG quantum dots, but also enables the PbG quantum dots to be protected by both the shell and the glass matrix at the same time, further improving the mechanical stability, thermal stability and chemical stability of the PbG quantum dots. In addition, the alkali metal halide crystal is 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 crystal exists in at least one of a first form and a second form. Wherein, the first form is a shell form, so that the alkali metal halide crystal coats at least part of the outer surface of the PbG quantum dots, and the two are connected by a lead halide bond. The second form is a dispersed crystal form, so that the alkali metal halide crystal is distributed in a dispersed manner on the outer surface of the PbG quantum dots, and the two are connected by a lead halide bond.

[0158] Regarding the alkali metal halide crystal in the quantum dot optical fiber core, reference can be made to the relevant description of the quantum dot glass above.

[0159] The quantum dot optical fiber provided by the embodiments of the present disclosure can adjust the particle size of the PbG quantum dots by adjusting the heat treatment process, so as to realize the regulation of the absorption and luminescence of the quantum dot optical fiber core in the wavelength range of 900nm - 2400nm.

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

[0161] Of course, the quantum dot glass products 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 by the embodiments of the present disclosure can realize the adjustment of the absorption spectrum and emission spectrum in the near-infrared to mid-infrared band, making it have great application potential in the fields of infrared detection and near-infrared fluorescence.

[0163] An optical fiber amplifier is a very important device in an optical fiber communication line. In a backbone long-distance optical communication network, the signal power continuously attenuates as the transmission distance increases. Therefore, an amplifier is needed to amplify the signal every certain transmission distance. A typical amplifier is an erbium-doped optical fiber amplifier. The working principle is to couple the signal light and the pump light into the erbium-doped optical fiber through a wavelength division multiplexer, and at the same time, an isolator is added to ensure the forward transmission of the optical signal.

[0164] Currently, the noise figure of the erbium-doped optical fiber amplifier is relatively high. One implementation is that the existing erbium-doped optical fiber can be replaced with the quantum dot glass or quantum dot optical fiber provided by the embodiments of the present disclosure to obtain a new type of amplifier, thereby achieving a lower noise figure.

[0165] Among them, the central wavelength of the new type of amplifier based on the quantum dot glass product of the embodiments of the present disclosure can be controlled by the central particle size of the quantum dots, the working bandwidth can be controlled by the size distribution of the quantum dots, and the central particle size and size distribution of the quantum dots can be controlled by different heat treatment conditions, thus providing a new way for expanding the optical fiber communication waveband and industrial application.

[0166] Exemplarily, referring to Figure 21 , the structure of an amplifier 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 optical fiber). The signal light is output from the signal source 1 and enters the isolator 2 to ensure the forward transmission of the optical signal, then enters the wavelength division multiplexer 3, and then the signal light enters the quantum dot glass product 5 for optical amplification and outputs the amplified signal light. At the same time, the pump light is output from the pump source 4, enters the wavelength division multiplexer 3, and then the pump light enters the quantum dot glass product 5 and the pump light enters the quantum dot optical fiber 6. Among them, after the signal light and the pump light are coupled in the wavelength division multiplexer, they enter the quantum dot glass product 5 so that the signal can be amplified and output.

[0167] 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. For those techniques or conditions not specified in the examples, they shall be in accordance with the techniques or conditions described in the literature in this field or in accordance with the product specifications. For the reagents or instruments whose manufacturers are not indicated, they are all conventional products that can be obtained commercially.

[0168] Examples 1-8 below all provide a quantum dot glass raw material, and the formulations of these quantum dot glass raw materials are shown in Table 1 respectively, where " / " in Table 1 represents the absence of this item.

[0169] Among the raw materials for preparing the quantum dot glass of Examples 1-8, Si element exists in the form of silicon dioxide (SiO 2 ); B element exists in the form of boron oxide (B 2 O 3 ); Al element exists in the form of aluminum oxide (Al 2 O 3 ); S element exists in the form of sodium sulfide (Na2S) and / or S elemental form; Pb element exists in the form of lead oxide (PbO); alkaline earth metal elements exist in the form of alkaline earth metal carbonate compounds. For example, Ca element exists in the form of calcium carbonate (CaCO 3 ), Sr element exists in the form of strontium carbonate (SrCO 3 ), and Ba element exists in the form of barium carbonate (BaCO 3 ). Alkali metal element M exists in the form of alkali metal carbonate compounds and alkali metal halides. For example, Na element exists in the form of sodium carbonate (Na 2 CO 3 ), and at least one of the forms of sodium chloride (NaCl), sodium bromide (NaBr), and sodium iodide (NaI); K element exists in the form of potassium carbonate (K 2 CO 3 ), and at least one of the forms of potassium chloride (KCl), potassium bromide (KBr), and potassium iodide (KI); Li element exists in the form of lithium carbonate (Li 2 CO 3 ), and at least one of the forms of lithium chloride (LiCl), lithium iodide (LiI), or lithium bromide (LiBr). Halogen element X exists in the form of alkali metal halides. For example, Cl element exists in the form of sodium chloride (NaCl) or potassium chloride (KCl), Br element exists in the form of sodium bromide (NaBr), and I element exists in the form of sodium iodide (NaI).

[0170] Table 1

[0171]

[0172] Example 1

[0173] In Example 1, quantum dot glass was prepared by the following method: providing the raw materials for preparing the quantum dot glass that were uniformly mixed, and the elemental composition of the raw materials for preparing the quantum dot glass conformed to the elemental composition in the quantum dot glass raw materials of Example 1 in Table 1. The raw materials for preparing the quantum dot glass were placed in a crucible for melting treatment, the melting temperature was 1500 °C, and the melting time was 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, the annealing temperature was 400 °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 heat treatment was carried out at 570 °C - 590 °C for 10 hours or 20 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on their surfaces in the glass matrix to obtain a series of quantum dot glasses.

[0174] A series of quantum dot glasses prepared in Example 1 were PbS / NaBr core-shell quantum dot glasses, which had PbS quantum dots in their glass matrix and a NaBr shell layer on the outer surface of the PbS quantum dots.

[0175] The following tests were carried out on a series of quantum dot glasses prepared in Example 1. Among them, 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. Thus, the numbers of these quantum dot glasses were defined as: 57010, 58010, 59010. And there was also a quantum dot glass with a heat treatment temperature of 580 °C and a heat treatment time of 20 hours. Thus, the number of this quantum dot glass was defined as: 58020.

[0176] The glass intermediate involved in Example 1 was called the original sample (abbreviated as AP). X-ray diffraction analysis (XRD) was carried out on the original sample and a series of quantum dot glasses provided in Example 1. The obtained X-ray diffraction patterns are shown in the appendix Figure 1 . As shown in the appendix Figure 1 , for the AP sample, only the "breadth peak" of the glass phase existed, and there was no crystal diffraction peak. For a series of quantum dot glasses after heat treatment, crystal diffraction peaks appeared at 570 °C, and the diffraction peaks matched those of the NaBr crystal, indicating that NaBr crystals were precipitated in the glass. As the heat treatment temperature increased, the size of the NaBr crystals gradually grew, and the corresponding diffraction peak intensity gradually increased.

[0177] Absorption spectrum tests were carried out on the original sample and a series of quantum dot glasses provided in Example 1. As shown in the appendix Figure 2As shown, 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 towards the long wavelength band. This indicates that PbS / NaBr core-shell structure quantum dots precipitate in the glass sample prepared in Example 1, and the size of the PbS quantum dots gradually grows as the heat treatment temperature increases.

[0178] A series of quantum dot glasses provided in Example 1 were tested for their emission spectra (also known as fluorescence spectra), with an excitation wavelength of 800 nm. As shown in the appendix Figure 3 As shown, there is no fluorescence peak in the AP sample. As the heat treatment temperature increases, the fluorescence peak of the quantum dot glass gradually shifts towards the long wavelength band. This indicates that PbS / NaBr core-shell structure quantum dots precipitate in the glass sample prepared in Example 1, and the size of the PbS quantum dots gradually increases as the heat treatment temperature increases and the heat treatment time prolongs.

[0179] The luminous efficiency of a quantum dot glass provided in Example 1 was tested. The heat treatment temperature and time of this quantum dot glass were 580 °C / 10 hours respectively, and its excitation wavelength was 650 nm. The test results are shown in Figure 4 , where Figure 4 The solid black-gray squares in refer to the emission spectrum of the 650 nm excitation light source, and the hollow circles are the emission spectra of the quantum dot glass. As shown in the appendix Figure 4 As shown, under the excitation of a 650 nm wavelength light source, the luminous efficiency of this quantum dot glass is as high as 75%. This is because the surface defects of the PbS quantum dots are effectively passivated by the alkali metal halide crystals, thus effectively improving the quantum dot luminous efficiency.

[0180] Example 2

[0181] In Example 2, quantum dot glass was prepared by the following method: Provide the preparation raw materials of the quantum dot glass that are uniformly mixed, and the elemental composition of the preparation raw materials of the quantum dot glass conforms to the elemental composition in the quantum dot glass raw materials of Example 2 in Table 1. Place the preparation raw materials of the quantum dot glass in a crucible for melting treatment, with a melting temperature of 1380 °C and a melting time of 60 minutes to obtain a molten glass liquid. After the molten glass liquid cools, a glass precursor is formed, which is transferred to an annealing furnace for annealing treatment, with an annealing temperature of 380 °C and an annealing time of 5 hours to obtain a yellow transparent glass intermediate. Transfer the glass intermediate to a heat treatment furnace for heat treatment, and heat treat it at 550 °C - 600 °C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on their surfaces in the glass matrix to obtain a series of quantum dot glasses.

[0182] A series of quantum dot glasses prepared in Example 2 are PbS / NaCl core-shell quantum dot glasses, which have PbS quantum dots and an NaCl shell layer on the outer surface of the PbS quantum dots in the glass matrix.

[0183] A series of quantum dot glasses prepared in Example 2 were tested as follows. Among them, 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. Thus, the numbers of these quantum dot glasses were defined as: 55010, 56010, 57010, 58010, 59010, 60010.

[0184] The glass intermediate involved in Example 2 was called the original sample (abbreviation: AP). The original sample and a series of quantum dot glasses provided in Example 2 were subjected to X-ray diffraction treatment. The obtained X-ray diffraction patterns are shown in the appendix Figure 5 . As shown in the appendix Figure 5 , only the "breadth peak" of the glass phase exists in the AP sample, and there is no crystal diffraction peak. For a series of quantum dot glasses after heat treatment, crystal diffraction peaks appear at 570 °C, and the diffraction peaks match those of NaCl crystals, indicating that NaCl crystals precipitate 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.

[0185] The original sample and a series of quantum dot glasses provided in Example 2 were subjected to absorption spectrum tests. As shown in the appendix Figure 6 , 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 wavelength band, indicating that PbS / NaCl core-shell structure quantum dots precipitate in the glass sample prepared in Example 2, and the size of the PbS quantum dots gradually grows as the heat treatment temperature increases.

[0186] A series of quantum dot glasses provided in Example 2 were subjected to luminescence spectrum tests, and the excitation wavelength was 800 nm. As shown in the appendix Figure 7 , there is no fluorescence peak in the AP sample. As the heat treatment temperature increases, the fluorescence peak of the quantum dot glass gradually shifts to the long wavelength band, indicating that PbS / NaBr core-shell structure quantum dots precipitate in the glass sample prepared in Example 2, and the size of the PbS quantum dots gradually increases as the heat treatment temperature increases and the heat treatment time prolongs.

[0187] A transmission electron microscope scanning test was carried out on a quantum dot glass provided in Example 2, and the heat treatment temperature and time of this quantum dot glass were 590 °C / 10 hours respectively. As shown in the appendix Figure 8As shown, it exemplifies that the NaCl crystal is semi-coated on the outside of the PbS quantum dots. Among them, the crystal grains with a grain size of about 25 nm are NaCl crystals, and the crystal grains with a grain size of about 5 nm are PbS quantum dots. The NaCl crystal and the PbS quantum dots form a semi-surrounding core-shell structure.

[0188] The luminous efficiency of a quantum dot glass provided in Example 2 was tested. The heat treatment temperature and time of this quantum dot glass were 570 °C / 10 hours respectively, and its excitation wavelength was 650 nm. The test results are shown in Figure 9 , where Figure 9 The solid black triangle blocks in refer to the emission spectrum of the 650 nm excitation light source, and the hollow circles are the emission spectra of the quantum dot glass. As shown in the appendix Figure 9 As shown, under the excitation of a 650 nm wavelength light source, the luminous efficiency of this quantum dot glass is as high as 78%. This is because the alkali metal halide crystal effectively passivates the surface defects of the PbS quantum dots, thereby effectively improving the quantum dot luminous efficiency.

[0189] Example 3

[0190] A series of quantum dot glasses were prepared in Example 3, and they were prepared by the following method: Provide the preparation raw materials of the quantum dot glass that are uniformly mixed. The elemental composition of the preparation raw materials of the quantum dot glass conforms to the elemental composition in the quantum dot glass raw materials of Example 3 in Table 1. Place the preparation raw materials of the quantum dot glass in a crucible for melting treatment. The melting temperature is 1350 °C and the melting time is 60 minutes to obtain a molten glass liquid. After the molten glass liquid cools, a glass precursor is formed, which is transferred to an annealing furnace for annealing treatment. The annealing temperature is 350 °C and the annealing time is 5 hours to obtain a yellow transparent glass intermediate. Transfer the glass intermediate to a heat treatment furnace for heat treatment, and heat-treat it at 570 °C - 590 °C for 10 hours, so as to precipitate PbS quantum dots and alkali metal halide crystals on their surfaces in the glass matrix, and obtain a series of quantum dot glasses.

[0191] A 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. After X-ray diffraction testing, no particularly obvious NaI crystal diffraction peaks were found in the quantum dot glass of Example 3. This may be due to the small content or small particle size of the NaI crystals. At this time, the surface defect passivation process of the PbS quantum dots is mainly that the NaI crystals are distributed in a dispersed state on the outer surface of the PbS quantum dots, and the iodine atoms are bonded to the lead atoms for passivation.

[0192] A series of quantum dot glasses prepared in Example 3 were tested as follows. Among them, 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. Thus, the numbers of these quantum dot glasses were defined as: 57010, 58010, and 59010.

[0193] The glass intermediate involved in Example 3 was called the original sample (abbreviation: AP). The original sample and a series of quantum dot glasses provided in Example 3 were subjected to X-ray diffraction treatment. The obtained X-ray diffraction patterns are shown in the appendix Figure 10 . As shown in the appendix Figure 10 , only the "hump peak" of the glass phase existed in the AP sample, and there was no crystal diffraction peak. For the series of quantum dot glasses after heat treatment, crystal diffraction peaks appeared at 570 °C, and the diffraction peaks matched those of the PbS crystal, indicating that PbS crystals precipitated in the glass. As the heat treatment temperature increased, the size of the PbS crystals gradually grew, and the corresponding diffraction peak intensity gradually increased.

[0194] The original sample and a series of quantum dot glasses provided in Example 3 were subjected to absorption spectrum testing. As shown in the appendix Figure 11 , there was no absorption peak in the AP sample. As the heat treatment temperature increased, the absorption peak of the quantum dot glass gradually shifted to the long wavelength band, indicating that PbS quantum dots precipitated in the glass sample prepared in Example 3, and the size of the PbS quantum dots gradually grew as the heat treatment temperature increased.

[0195] A series of quantum dot glasses provided in Example 3 were subjected to luminescence spectrum testing, and the excitation wavelength was 800 nm. As shown in the appendix Figure 12 , as the heat treatment temperature increased, the fluorescence peak of the quantum dot glass gradually shifted to the long wavelength band, indicating that PbS quantum dots precipitated in the glass sample prepared in Example 3, and the size of the PbS quantum dots gradually increased as the heat treatment temperature increased and the heat treatment time extended.

[0196] A quantum dot glass provided in Example 3 was subjected to luminescence efficiency testing. The heat treatment temperature and time of this quantum dot glass were 590 °C / 10 hours respectively, and the excitation wavelength was 650 nm. The test results are shown in Figure 13 , where Figure 13 the solid black squares refer to the luminescence spectrum of the 650 nm excitation light source, and the hollow circles are the luminescence spectrum of this quantum dot glass. Combining the luminescence spectrum diagram shown in Figure 13 , it can be seen that under the excitation of the 650 nm wavelength light source, the luminescence efficiency of this quantum dot glass is as high as 70%, because the alkali metal halide crystal effectively passivates the surface defects of the PbS quantum dots, thus effectively improving the quantum dot luminescence efficiency.

[0197] Example 4

[0198] Example 4 prepared quantum dot glass, which was prepared by the following method: providing the preparation raw materials of the quantum dot glass that were uniformly mixed, and the elemental composition of the preparation raw materials of the quantum dot glass conformed to the elemental composition in the quantum dot glass raw materials of Example 4 in Table 1. Placing the preparation raw materials of the quantum dot glass in a crucible for melting treatment, the melting temperature was 1300 °C, and the melting time was 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, the annealing temperature was 350 °C, and the annealing time was 5 hours to obtain a yellow transparent glass intermediate. Transferring the glass intermediate to a heat treatment furnace for heat treatment, and heat-treating at 570 °C - 600 °C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on the surface thereof in the glass matrix to obtain a series of quantum dot glasses.

[0199] The glass matrix of the series of quantum dot glasses prepared in Example 4 has PbS quantum dots, and NaCl crystals in the form of a shell layer and dispersed NaI crystals on the outer surface of the PbS quantum dots.

[0200] The following tests were performed on the series of quantum dot glasses prepared in Example 4. Among them, 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. Thus, the numbers of these quantum dot glasses were defined as: 57010, 58010, 59010.

[0201] The glass intermediate involved in Example 4 was called the original sample (abbreviation: AP). Absorption spectrum tests were performed on the original sample provided in Example 4 and the series of quantum dot glasses, as shown in the appendix Figure 14 As shown, there was no absorption peak in the AP sample. As the heat treatment temperature increased, the absorption peak of the quantum dot glass gradually shifted to the long wavelength band, indicating that PbS quantum dots were precipitated in the glass sample prepared in Example 4, and the size of the PbS quantum dots gradually increased as the heat treatment temperature increased.

[0202] Luminescence spectrum tests were performed on the series of quantum dot glasses provided in Example 4, and the excitation wavelength was 800 nm. As shown in the appendix Figure 15 As shown, as the heat treatment temperature increased, the fluorescence peak of the quantum dot glass gradually shifted to the long wavelength band, indicating that PbS quantum dots were precipitated in the glass sample prepared in Example 4, and the size of the PbS quantum dots gradually increased as the heat treatment temperature increased and the heat treatment time prolonged. Among them, Figure 15Among them, the quantum dot glass numbered 59010 is represented by the ▲ symbol, and the quantum dot glass numbered 60010 is represented by the ▼ symbol.

[0203] The luminous efficiency of a series of quantum dot glasses provided in Example 4 was tested, and its excitation wavelength was 650 nm. The test results are shown in Figure 16 , where Figure 16 The solid black squares in refer to the emission spectrum of the 650 nm excitation light source, and the hollow circles, hollow triangles, and hollow pentagrams are the quantum dot glasses 57010, 58010, and 59010 respectively. As shown in the appendix Figure 16 As shown, under the excitation of a 650 nm wavelength light source, the luminous efficiency of this quantum dot glass is as high as 70%. This is because the surface defects of PbS quantum dots are effectively passivated by alkali metal halide crystals, thereby effectively improving the luminous efficiency of quantum dots. In addition, this also confirms that when the shell layer is an alkali metal halide with a mixed halogen element, it also plays a role in improving the luminous efficiency of quantum dots.

[0204] Example 5

[0205] In Example 5, quantum dot glasses were prepared by the following method: Provide the preparation raw materials of the quantum dot glass that are uniformly mixed, and the elemental composition of the preparation raw materials of the quantum dot glass conforms to the elemental composition in the quantum dot glass raw materials of Example 5 in Table 1. Place the preparation raw materials of the quantum dot glass in a crucible for melting treatment, with a melting temperature of 1300 °C and a melting time of 60 minutes to obtain a molten glass liquid. After the molten glass liquid cools, a glass precursor is formed, which is transferred to an annealing furnace for annealing treatment, with an annealing temperature of 350 °C and an annealing time of 5 hours to obtain a yellow transparent glass intermediate. Transfer the glass intermediate to a heat treatment furnace for heat treatment, and heat treat it at 610 °C - 630 °C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on their surfaces in the glass matrix to obtain a series of quantum dot glasses.

[0206] A series of quantum dot glasses prepared in Example 5 include: PbS quantum dots and NaI crystals on the outer surface of the PbS quantum dots.

[0207] The following tests were performed on a series of quantum dot glasses prepared in Example 5. Among them, the heat treatment temperatures of these quantum dot glasses are 610 °C, 620 °C, and 630 °C respectively, and the heat treatment time is 10 hours. Therefore, the numbers of these quantum dot glasses are defined as: 61010, 62010, and 63010 respectively.

[0208] The emission spectrum of a series of quantum dot glasses provided in Example 5 was tested, and its excitation wavelength was 800 nm. As shown in the appendix Figure 17As shown, as the heat treatment temperature increases, the fluorescence peak of the quantum dot glass gradually shifts towards the long wavelength band, indicating that PbS quantum dots precipitate in the glass sample prepared in Example 5, and the size of the PbS quantum dots gradually grows as the heat treatment temperature increases.

[0209] The luminous efficiency of a quantum dot glass provided in Example 5 was tested. The heat treatment temperature and time of this quantum dot glass were 620 °C / 10 hours respectively. The test results showed that the absolute quantum efficiency of this quantum dot glass was 72%.

[0210] Example 6

[0211] In Example 6, quantum dot glass was prepared by the following method: Provide the preparation raw materials of the quantum dot glass that are uniformly mixed. The elemental composition of the preparation raw materials of the quantum dot glass conforms to the elemental composition in the quantum dot glass raw materials of Example 6 in Table 1. Place the preparation raw materials of the quantum dot glass in a crucible for melting treatment. The melting temperature is 1280 °C and the melting time is 60 minutes to obtain a molten glass liquid. After the molten glass liquid cools, form a glass precursor, transfer it to an annealing furnace for annealing treatment. The annealing temperature is 330 °C and the annealing time is 5 hours to obtain a yellow transparent glass intermediate. Transfer the glass intermediate to a heat treatment furnace for heat treatment, and heat treat it at 570 °C - 650 °C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on the surface thereof in the glass matrix to obtain a series of quantum dot glasses.

[0212] In the glass matrix of the series of quantum dot glasses prepared in Example 6, there are PbS quantum dots, and NaCl crystals in the form of a shell layer, KCl crystals in the form of a shell layer, and dispersed NaI crystals on the outer surface of the PbS quantum dots.

[0213] The following tests were carried out on a series of quantum dot glasses prepared in Example 6. Among them, the heat treatment temperatures of these quantum dot glasses were 570 °C, 580 °C, 590 °C, 600 °C, 620 °C, 640 °C, 650 °C respectively, and the heat treatment time was 10 hours. Thus, the numbers of these quantum dot glasses were defined as: 57010, 58010, 59010, 60010, 62010, 64010, 65010.

[0214] The emission spectra of a series of quantum dot glasses provided in Example 6 were tested, and the excitation wavelength was 800 nm. As shown in the appendix Figure 18 As shown, as the heat treatment temperature increases, the fluorescence peak of the quantum dot glass gradually shifts towards the long wavelength band, indicating that PbS quantum dots precipitate in the glass sample prepared in Example 6, and the size of the PbS quantum dots gradually grows as the heat treatment temperature increases. Among them, Figure 18Among them, the quantum dot glass numbered 62010 is represented by the △ symbol, the quantum dot glass numbered 64010 is represented by the ◇ symbol, and the quantum dot glass numbered 65010 is represented by the ☆ symbol.

[0215] The luminous efficiency of a quantum dot glass provided in Example 6 was tested. The heat treatment temperature and time of this quantum dot glass were 640 °C / 10 hours respectively. The test results showed that the absolute quantum efficiency of this quantum dot glass was 75%.

[0216] Example 7

[0217] Example 7 prepared quantum dot glass, which was prepared by the following method: Provide the preparation raw materials of the quantum dot glass that are uniformly mixed. The elemental composition of the preparation raw materials of the quantum dot glass conforms to the elemental composition in the quantum dot glass raw materials of Example 7 in Table 1. Place the preparation raw materials of the quantum dot glass in a crucible for melting treatment. The melting temperature is 1250 °C and the melting time is 60 minutes to obtain a molten glass liquid. After the molten glass liquid cools, a glass precursor is formed and transferred to an annealing furnace for annealing treatment. The annealing temperature is 320 °C and the annealing time is 5 hours to obtain a yellow transparent glass intermediate. Transfer the glass intermediate to a heat treatment furnace for heat treatment, and heat treat 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.

[0218] The glass matrix of a series of quantum dot glasses prepared in Example 7 has PbS quantum dots, and LiCl crystals in the form of a shell layer and dispersed LiBr crystals on the outer surface of the PbS quantum dots.

[0219] The following tests were carried out on a series of quantum dot glasses prepared in Example 7. Among them, 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. Thus, the numbers of these quantum dot glasses were defined as: 57010, 58010, 59010, 60010.

[0220] The emission spectra of a series of quantum dot glasses provided in Example 7 were tested, and the excitation wavelength was 800 nm. As shown in the appendix Figure 19 As shown, as the heat treatment temperature increases, the fluorescence peak of the quantum dot glass gradually shifts to the long wavelength band, which indicates that PbS quantum dots are precipitated in the glass sample prepared in Example 7, and the size of the PbS quantum dots gradually grows as the heat treatment temperature increases.

[0221] The luminescence efficiency of a quantum dot glass provided in Example 7 was tested. The heat treatment temperature and time of this quantum dot glass were 570 °C / 10 hours respectively. The test results showed that the absolute quantum efficiency of this quantum dot glass was 70%.

[0222] Example 8

[0223] Quantum dot glasses were prepared in Example 8, and they were prepared by the following method: Provide the raw materials for preparing the quantum dot glass that are uniformly mixed. The elemental composition of the raw materials for preparing the quantum dot glass conforms to the elemental composition in the raw materials of the quantum dot glass in Example 8 in Table 1. Place the raw materials for preparing the quantum dot glass in a crucible for melting treatment. The melting temperature is 1200 °C and the melting time is 60 minutes to obtain a molten glass liquid. After the molten glass liquid cools, a glass precursor is formed, which is transferred to an annealing furnace for annealing treatment. The annealing temperature is 300 °C and the annealing time is 5 hours to obtain a yellow transparent glass intermediate. Transfer the glass intermediate to a heat treatment furnace for heat treatment, and heat-treat it at 570 °C - 600 °C for 10 hours, thereby precipitating PbS quantum dots and alkali metal halide crystals on their surfaces in the glass matrix to obtain a series of quantum dot glasses.

[0224] The glass matrix of a series of quantum dot glasses prepared in Example 8 has PbS quantum dots, and also has dispersed NaCl crystals, dispersed NaBr crystals, and dispersed NaI crystals on the outer surface of the PbS quantum dots.

[0225] A series of quantum dot glasses prepared in Example 8 were tested as follows. Among them, 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. Thus, the numbers of these quantum dot glasses were defined as: 57010, 58010, 59010, 60010.

[0226] The luminescence spectra of a series of quantum dot glasses provided in Example 8 were tested, and their excitation wavelength was 800 nm. As shown in the appendix Figure 20 As shown, as the heat treatment temperature increases, the fluorescence peak of the quantum dot glass gradually shifts to the long wavelength band, which indicates that PbS quantum dots precipitate in the glass samples prepared in Example 8, and the size of the PbS quantum dots gradually grows as the heat treatment temperature increases.

[0227] The luminescence efficiency of a quantum dot glass provided in Example 8 was tested. The heat treatment temperature and time of this quantum dot glass were 590 °C / 10 hours respectively. The test results showed that the absolute quantum efficiency of this quantum dot glass was 76%.

[0228] The above description is only for the convenience of those skilled in the art to understand the technical solution of the present disclosure, and is not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A quantum dot glass raw material, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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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