A CdS quantum dot glass, its preparation method, and its application as a light source

Abstract

This invention relates to a novel CdS quantum dot glass, its preparation method, and its application in a light source. The basic glass raw materials are composed of the following mass percentages: black talc powder: 55–70 wt.%; K₂CO₃: 5–15 wt.%; Li₂CO₃: 5–15 wt.%; SrCO₃: 5–10 wt.%; H₃BO₃: 5–20 wt.%; CdS: 1–15 wt.%; the content of the external rare earth compound is 0–2 wt.% of the total mass of the other raw materials (black talc powder + K₂CO₃ + Li₂CO₃ + SrCO₃ + H₃BO₃ + CdS); the content of the external clarifying agent is 0.2–2 wt.% of the total mass of the other raw materials (black talc powder + K₂CO₃ + Li₂CO₃ + SrCO₃ + H₃BO₃ + CdS). This invention relates to the field of glass materials technology. The raw materials used in its preparation are readily available, the process is simple, and it is easy to industrialize. The resulting CdS quantum dot glass can be effectively excited by 395nm violet light and has the characteristics of high luminous efficiency, excellent resistance to thermal quenching, and adjustable light color. The encapsulated white light source has the characteristics of warm white light output, high color rendering index, and high lumen efficiency.

Description

Technical Field

[0001] This invention relates to the field of glass materials technology, and in particular to a CdS quantum dot glass, its preparation method, and its application as a light source. Background Technology

[0002] As quasi-zero-dimensional nanomaterials, quantum dots possess unique photoelectric properties distinct from macroscopic systems due to their quantum confinement effect. Compared to bulk materials, semiconductor quantum dots exhibit optical advantages such as broad excitation spectra, tunable emission wavelengths, narrow half-peak fluorescence characteristics, and excellent photostability. CdS quantum dots, with their wide bandgap and strong exciton binding energy, can achieve efficient intrinsic photoluminescence at room temperature. Through size control and composition design, full-spectrum emission in the visible light domain can be achieved, giving them unique application value in nonlinear optics, spectral down-conversion, and other fields, leading to their widespread use in solid-state lighting, laser devices, optical communication, and photovoltaic devices.

[0003] Currently, numerous researchers have conducted extensive studies on the structure and various properties of CdS quantum dots. Examples include: CN114149803A, which proposes a one-pot aqueous synthesis method for CdS quantum dots and its applications; CN117186893A, which proposes a CdSe@CdS core-shell quantum dot method and its preparation and applications; CN112159652A, which proposes a preparation method for CdSe / CdS core-shell structured quantum dots; and CN113322070A, which proposes a CdS / CdSe heterojunction quantum dot with a core / shell structure and its preparation method. These existing technologies utilize aqueous one-pot methods, biosynthesis, chemical solution methods, and solvothermal methods to synthesize CdS quantum dot materials. While these methods have become mainstream preparation techniques due to their simplicity, mild reaction conditions, and ease of surface modification, their practical applications are limited by poor quantum dot dispersion, low crystallinity, susceptibility to agglomeration, and numerous surface defects. To address this bottleneck, the academic community has developed optimization strategies such as surface passivation, coating modification, and core-shell structure construction. Among these, the approach of encapsulating quantum dots in a glass matrix has significant advantages. Glass matrices, due to their mature fabrication process, high morphological flexibility, low cost, and excellent thermal and chemical stability, can effectively suppress quantum dot aggregation and reduce surface defects, thereby obtaining functional materials with both high stability and optical properties.

[0004] In recent decades, scholars have extensively studied the luminescence properties of CdS quantum dot glasses and made significant progress. However, despite considerable efforts in the synthesis and performance modulation of CdS quantum dot glasses in existing research, improvements in the long-term stability and luminescence efficiency of the obtained quantum dot glass materials remain limited. For example, CN106865980B proposed a praseodymium-doped CdS quantum dot glass and its preparation method, but there was no relevant research on the quantum efficiency and high-temperature stability of CdS quantum dot glasses. Furthermore, impurity phases precipitated in CdS quantum dot glasses can also adversely affect the luminescence performance of the material. Furthermore, Kuznetsova et al. (Ceramics International 48(2022)18972-18982), Li et al. (Chemical Engineering Journal 410(2021)128324), and Chen et al. (Nanoscale Advances 5(2023)1397-1404) reported CdS quantum dot glasses, CdS quantum dot glasses, and CdSe / CdS core-shell structured quantum dot glasses, respectively. However, the internal quantum efficiency of the prepared quantum dot glasses is still low (<60%). Therefore, by precisely adjusting the crystallization process and controlling the interfacial properties between the quantum dots and the glass substrate, the size of CdS quantum dots can be controlled, the emission peak position can be fine-tuned, and defects between the CdS quantum dot surface and the glass substrate can be reduced. This is of great significance for improving the crystallization characteristics, luminous efficiency, and long-term stability of CdS quantum dot glasses, thereby expanding their applications in white light illumination, screen displays, and other related fields. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a CdS quantum dot glass, its preparation method, and its application as a light source. The raw materials used in its preparation are readily available, the process is simple, and it is easy to industrialize. The resulting CdS quantum dot glass can be effectively excited by 395nm violet light, exhibiting high luminous efficiency, excellent resistance to thermal quenching, and tunable light color. The encapsulated white light source features warm white light output, high color rendering index, and high lumen efficiency, thereby solving the technical problems mentioned in the background section.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0007] A CdS quantum dot glass comprises the following basic glass raw materials by mass percentage: black talc powder: 55-70 wt.%; K2CO3: 5-15 wt.%; Li2CO3: 5-15 wt.%; SrCO3: 5-10 wt.%; H3BO3: 5-20 wt.%; CdS: 1-15 wt.%; the content of externally added rare earth compounds is 0-2 wt.% of the total mass of other raw materials (black talc powder + K2CO3 + Li2CO3 + SrCO3 + H3BO3 + CdS); the content of externally added clarifying agent is 0.2-2 wt.% of the total mass of other raw materials (black talc powder + K2CO3 + Li2CO3 + SrCO3 + H3BO3 + CdS).

[0008] Preferably, the black talc powder has a particle size of 75–150 μm; the externally doped rare earth ions are Eu. 3+ The raw materials are rare earth oxides Eu2O3 or rare earth carbonates Eu2(CO3)3.

[0009] Preferably, the clarifying agent is one or a combination of two of Sb2O3 or NaSbO3.

[0010] The quantum dot glass prepared above emits tunable strong light under 395nm violet light excitation, with an emission peak between 500 and 750nm, an internal quantum efficiency of >60%, and a luminescence intensity at 150℃ that is more than 85% of the luminescence intensity at room temperature.

[0011] A method for preparing CdS quantum dot glass includes the following steps:

[0012] S1. Weigh each raw material precisely according to the predetermined mass percentage, put them into an agate mortar and grind for 0.2 to 4 hours to obtain a uniform mixture;

[0013] S2, the obtained mixture is placed into a corundum crucible and placed in a melting furnace and heated from room temperature to 1100-1300℃ and held for 0.1-1h to obtain glass melt. The glass melt is then poured into water for water quenching to obtain glass fragments.

[0014] S3, take out the glass fragments, wash, dry, grind into powder, put them back into the melting furnace to melt, repeat the above steps S1 and S2 multiple times to obtain a uniformly melted glass liquid;

[0015] S4. After the glass melt is uniformly melted, the glass melt is quickly taken out from the melting furnace at 1100-1300℃ and poured onto a mold preheated to 250-330℃ to press it into shape. Then, the formed block glass is quickly transferred into an annealing furnace at the same temperature and kept for 5-30 hours. After annealing, the annealing furnace is cooled to room temperature.

[0016] S5, After cutting and polishing the obtained base glass, place the glass in a muffle furnace at the glass transition temperature T. g Around +50℃, from the crystallization initiation temperature T0 to the crystallization temperature T c The nucleation and crystallization processes were carried out using a synergistic process of "critical saturation nucleation & controlled growth crystallization".

[0017] The “critical saturation nucleation-controlled growth crystallization” synergistic process refers to the establishment of a new theory of time-domain decoupling between nucleation and crystallization. In the nucleation stage, it breaks through the traditional heat preservation time limit and achieves the extreme stability of crystal nucleus density by extending the heat preservation. In the crystallization stage, it adopts time window constraint technology to precisely cut off the excessive coarsening process of crystals, thereby achieving the purpose of preparing highly crystalline CdS quantum dot glass.

[0018] S6. After the heat treatment is completed, the muffle furnace is cooled to room temperature to obtain CdS quantum dot glass.

[0019] Preferably, the heating and cooling rates of the melting furnace in steps S2 and S4 are 5 to 30 °C / min.

[0020] Preferably, in the specific implementation of the "critical saturation nucleation-controlled growth crystallization" synergistic process described in step S5, during the glass nucleation stage (glass transition temperature T...), g The holding time is as long as 12 to 96 hours at around +50℃, during the glass crystallization stage (from the crystallization start temperature T0 to the crystallization temperature T). c The heat preservation time is 2 to 36 hours.

[0021] An application of a white light source, using screen printing technology, to print BaMgAl 10 O 17 Eu 2+ Blue powder, Ba2SiO4:Eu 2+ Green powder, (Sr,Ca)AlSiN3:Eu 2+ Several phosphors in red powder are solidified with low-melting-point glass powder on the surface of CdS quantum dot glass and combined with LED chips to obtain a white light source.

[0022] The packaged white light source features warm white light output, low color temperature (CCT<4500K), high color rendering index (CRI>90), and high luminous efficacy (LE>70lm / W).

[0023] In summary, the present invention has at least one of the following beneficial technical effects:

[0024] 1. The raw materials for this invention are abundant and inexpensive, the production process is simple, the conditions are not strict, and it is suitable for industrial production;

[0025] 2. The CdS quantum dot glass obtained by this invention can be effectively excited by 395nm violet light and has the characteristics of adjustable light color, high thermal stability, and high quantum efficiency; the encapsulated white light source has the advantages of warm white light output, low color temperature, high color rendering index and high lumen efficiency, and can be used in white light lighting, screen display and other fields.

[0026] 3. This invention utilizes black talc powder as the main raw material, and after adding other components, prepares CdS quantum dot glass through the traditional "melting-quenching" method and the "critical saturation nucleation-controlled growth crystallization" synergistic process. This not only develops the high-value application of black talc in the optoelectronic field, but also provides an innovative path for achieving high-efficiency luminescence of high-crystallinity quantum dot glass. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 The image shows the XRD pattern of CdS quantum dot glass.

[0029] Figure 2 The orange-yellow light emission spectrum of CdS quantum dot glass.

[0030] Figure 3 The red light emission spectrum of CdS quantum dot glass.

[0031] Figure 4 For Eu 3+ Emission spectrum of CdS quantum dot glass.

[0032] Figure 5 The temperature-dependent emission spectrum of CdS quantum dot glass. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings.

[0034] Example 1:

[0035] Reference Figure 1 , Figure 2 and Figure 5 The present invention discloses a method for preparing CdS quantum dot glass, comprising the following steps:

[0036] S1. Accurately weigh the raw materials according to the predetermined mass percentages: black talc: 17.4000g; K2CO3: 3.0303g; Li2CO3: 3.0612g; SrCO3: 2.4242g; H3BO3: 6.0302g; CdS: 1.2001g; Sb2O3: 0.1508g. Grind the mixture in an agate mortar for 1.5 hours to obtain a uniform mixture.

[0037] S2, the obtained mixture is loaded into a corundum crucible and placed in a melting furnace. The temperature is raised from room temperature to 1200℃ at a heating rate of 12℃ / min and held for 0.5h to obtain glass melt. Then the glass melt is poured into water for water quenching to obtain glass fragments.

[0038] S3, take out the glass fragments, wash, dry, and grind them into powder; repeat the following process twice: put them into a melting furnace to melt, then quench them in water to obtain glass fragments, take out the obtained fragments, wash, dry, and grind them into powder; finally put the powder into a melting furnace to melt, and obtain a uniformly molten glass liquid;

[0039] S4. After the glass melt is uniformly melted, the glass melt is quickly taken out from the melting furnace at 1200℃ and poured onto a mold preheated to 270℃ to press into shape. Then, the formed block glass is quickly transferred into an annealing furnace at the same temperature and kept for 12 hours. After annealing, the annealing furnace is cooled to room temperature at a cooling rate of 15℃ / min.

[0040] S5, After cutting and polishing the obtained base glass, place the glass in a muffle furnace at the glass transition temperature T. g Around +50℃, from the crystallization initiation temperature T0 to the crystallization temperature T c The nucleation and crystallization processes were carried out using a synergistic process of "critical saturation nucleation & controlled growth crystallization". The temperature was raised from room temperature to 380℃ for nucleation and held for 30 hours, and then raised to 450℃ for crystallization and held for 10 hours.

[0041] S6. After the heat treatment is completed, the muffle furnace is cooled to room temperature to obtain CdS quantum dot glass.

[0042] In this embodiment, the CdS quantum dot glass exhibits an emission peak at 560 nm under 395 nm ultraviolet light excitation, with an internal quantum efficiency of 63.45%. Its luminescence intensity at 150 °C is 89.3% of that at room temperature. The BaMgAl nanoparticles were fabricated using a screen printing process. 10 O 17 Eu 2+ Blue powder, Ba2SiO4:Eu 2+Green powder, low melting point glass powder, 395nm LED and CdS quantum dot glass are encapsulated. After encapsulation, the color coordinates of the white light source are (0.3650, 0.3556). It has warm white light emission, color temperature CCT of 4324K, color rendering index CRI of 91.8 and luminous efficacy LE of 72.5lm / W.

[0043] Example 2

[0044] Reference Figure 1 As shown, a method for preparing CdS quantum dot glass includes the following steps:

[0045] S1. Accurately weigh the raw materials according to the predetermined mass percentages: black talc powder: 18.0000g; K2CO3: 3.6364g; Li2CO3: 2.1429g; SrCO3: 2.4242g; H3BO3: 3.6181g; CdS: 2.1002g; Sb2O3: 0.1508g; NaSbO3: 0.1531g. Grind the raw materials in an agate mortar for 1.5 hours to obtain a uniform mixture.

[0046] S2, the obtained mixture is loaded into a corundum crucible and placed in a melting furnace. The temperature is raised from room temperature to 1250℃ at a heating rate of 14℃ / min and held for 0.3h to obtain glass melt. The glass melt is then poured into water for water quenching to obtain glass fragments.

[0047] S3, take out the glass fragments, wash, dry, and grind them into powder; repeat the following process twice: put them into a melting furnace to melt, then quench them in water to obtain glass fragments, take out the obtained fragments, wash, dry, and grind them into powder; finally put the powder into a melting furnace to melt, and obtain a uniformly molten glass liquid;

[0048] S4. After the glass melt is uniformly melted, the glass melt is quickly taken out from the melting furnace at 1250℃ and poured onto a mold preheated to 300℃ to press and shape. Then, the shaped block glass is quickly transferred into an annealing furnace at the same temperature and kept for 14 hours. After annealing, the annealing furnace is cooled to room temperature at a cooling rate of 15℃ / min.

[0049] S5, After cutting and polishing the obtained base glass, place the glass in a muffle furnace at the glass transition temperature T. g Around +50℃, from the crystallization initiation temperature T0 to the crystallization temperature T c The nucleation and crystallization processes were carried out using a synergistic process of "critical saturation nucleation & controlled growth crystallization". The temperature was raised from room temperature to 390℃ for nucleation and held for 30 hours, and then raised to 460℃ for crystallization and held for 12 hours.

[0050] S6. After the heat treatment is completed, the muffle furnace is cooled to room temperature to obtain CdS quantum dot glass.

[0051] In this embodiment, the CdS quantum dot glass exhibits an emission peak at 575 nm under 395 nm ultraviolet light excitation, with an internal quantum efficiency of 65.00%. Its luminescence intensity at 150 °C is 87.23% of that at room temperature. The BaMgAl nanoparticles were fabricated using a screen printing process. 10 O 17 Eu 2+ Blue powder, Ba2SiO4:Eu 2+ Green powder, low melting point glass powder, 395nm LED and CdS quantum dot glass are encapsulated. After encapsulation, the color coordinates of the white light source are (0.3596, 0.3420). It has warm white light emission, color temperature CCT of 4422K, color rendering index CRI of 90.5 and luminous efficacy LE of 78.9lm / W.

[0052] Example 3

[0053] Reference Figure 1 and Figure 4 As shown, a method for preparing CdS quantum dot glass includes the following steps:

[0054] S1. Accurately weigh the raw materials according to the predetermined mass percentages: black talc powder: 18.6000g; K2CO3: 1.8182g; Li2CO3: 3.6735g; SrCO3: 2.7273g; H3BO3: 3.6181g; CdS: 1.5002g; Eu2O3: 0.3600g; Sb2O3: 0.1809g; NaSbO3: 0.3061g. Grind the mixture in an agate mortar for 2 hours to obtain a uniform mixture.

[0055] S2, the obtained mixture is loaded into a corundum crucible and placed in a melting furnace. The temperature is raised from room temperature to 1280℃ at a heating rate of 20℃ / min and held for 0.3h to obtain glass melt. The glass melt is then poured into water for water quenching to obtain glass fragments.

[0056] S3, Remove the glass fragments, wash, dry, and grind them into powder; repeat the following process 3 times: melt the powder in a melting furnace, quench it in water to obtain glass fragments, remove the obtained fragments, wash, dry, and grind them into powder; finally, melt the powder in a melting furnace to obtain a uniformly molten glass liquid;

[0057] S4. After the glass melt is uniformly melted, the glass melt is quickly taken out from the melting furnace at 1280℃ and poured onto a mold preheated to 300℃ to press and shape. Then, the shaped block glass is quickly transferred into an annealing furnace at the same temperature and kept for 16 hours. After annealing, the annealing furnace is cooled to room temperature at a cooling rate of 15℃ / min.

[0058] S5, After cutting and polishing the obtained base glass, place the glass in a muffle furnace at the glass transition temperature T. g Around +50℃, from the crystallization initiation temperature T0 to the crystallization temperature T c The nucleation and crystallization processes were carried out using a synergistic process of "critical saturation nucleation & controlled growth crystallization". The temperature was raised from room temperature to 390℃ for nucleation and held for 32 hours, followed by raising the temperature to 475℃ for crystallization and holding for 15 hours.

[0059] S6. After the heat treatment is completed, the muffle furnace is cooled to room temperature to obtain CdS quantum dot glass.

[0060] In this embodiment, the CdS quantum dot glass exhibits an emission peak at 590 nm under 395 nm ultraviolet light excitation, with an internal quantum efficiency of 68.23%. Its luminescence intensity at 150 °C is 89.56% of that at room temperature. The BaMgAl nanoparticles were fabricated using a screen printing process. 10 O 17 Eu 2+ Blue powder, Ba2SiO4:Eu 2+ Green powder, low melting point glass powder, 395nm LED and CdS quantum dot glass are encapsulated. After encapsulation, the color coordinates of the white light source are (0.3655, 0.3302). It has warm white light emission, color temperature CCT of 4122K, color rendering index CRI of 91.7 and luminous efficacy LE of 77.9lm / W.

[0061] Example 4

[0062] Reference Figure 1 and Figure 3 As shown, a method for preparing CdS quantum dot glass includes the following steps:

[0063] S1. Accurately weigh the raw materials according to the predetermined mass percentages: black talc powder: 20.1000g; K2CO3: 2.1212g; Li2CO3: 2.7551g; SrCO3: 1.8182g; H3BO3: 4.8241g; CdS: 0.9001g; Eu2(CO3)3: 0.1800g; Sb2O3: 0.3015g; NaSbO3: 0.1837g. Grind the mixture in an agate mortar for 1.5 hours to obtain a uniform mixture.

[0064] S2, the obtained mixture is loaded into a corundum crucible and placed in a melting furnace. The temperature is raised from room temperature to 1250℃ at a heating rate of 18℃ / min and held for 0.5h to obtain glass melt. Then the glass melt is poured into water for water quenching to obtain glass fragments.

[0065] S3, take out the glass fragments, wash, dry, and grind them into powder; repeat the following process twice: put them into a melting furnace to melt, then quench them in water to obtain glass fragments, take out the obtained fragments, wash, dry, and grind them into powder; finally put the powder into a melting furnace to melt, and obtain a uniformly molten glass liquid;

[0066] S4. After the glass melt is uniformly melted, the glass melt is quickly taken out from the melting furnace at 1250℃ and poured onto a mold preheated to 290℃ to press and shape. Then, the shaped block glass is quickly transferred into an annealing furnace at the same temperature and kept for 15 hours. After annealing, the annealing furnace is cooled to room temperature at a cooling rate of 12℃ / min.

[0067] S5, After cutting and polishing the obtained base glass, place the glass in a muffle furnace at the glass transition temperature T. g Around +50℃, from the crystallization initiation temperature T0 to the crystallization temperature T c The nucleation and crystallization processes were carried out using a synergistic process of "critical saturation nucleation & controlled growth crystallization". The temperature was raised from room temperature to 400℃ for nucleation and held for 48 hours, and then raised to 510℃ for crystallization and held for 18 hours.

[0068] S6. After the heat treatment is completed, the muffle furnace is cooled to room temperature to obtain CdS quantum dot glass.

[0069] In this embodiment, the CdS quantum dot glass exhibits an emission peak at 650 nm under 395 nm ultraviolet light excitation, with an internal quantum efficiency of 65.45%. Its luminescence intensity at 150 °C is 90.12% of that at room temperature. The Ba2SiO4:Eu... 2+ Green powder, (Sr,Ca)AlSiN3:Eu 2+ The white light source is encapsulated with red powder, low melting point glass powder, 395nm LED and CdS quantum dot glass. The color coordinates of the encapsulated white light source are (0.3585, 0.3456). It has warm white light emission, color temperature CCT of 4484K, color rendering index CRI of 90.3 and luminous efficacy LE of 81.5lm / W.

[0070] Example 5

[0071] Reference Figure 1 As shown, a method for preparing CdS quantum dot glass includes the following steps:

[0072] S1. Accurately weigh the raw materials according to the predetermined mass percentages: black talc powder: 19.500g; K2CO3: 1.8182g; Li2CO3: 3.6735g; SrCO3: 1.8182g; H3BO3: 3.6181g; CdS: 1.5002g; Eu2O3: 0.2100g; NaSbO3: 0.4592g. Grind the mixture in an agate mortar for 2 hours to obtain a uniform mixture.

[0073] S2, the obtained mixture is loaded into a corundum crucible and placed in a melting furnace. The temperature is raised from room temperature to 1280℃ at a heating rate of 15℃ / min and held for 0.2h to obtain glass melt. The glass melt is then poured into water for water quenching to obtain glass fragments.

[0074] S3, take out the glass fragments, wash, dry, and grind them into powder; repeat the following process twice: put them into a melting furnace to melt, then quench them in water to obtain glass fragments, take out the obtained fragments, wash, dry, and grind them into powder; finally put the powder into a melting furnace to melt, and obtain a uniformly molten glass liquid;

[0075] S4. After the glass melt is uniformly melted, the glass melt is quickly taken out from the melting furnace at 1280℃ and poured onto a mold preheated to 310℃ to press and shape. Then, the shaped block glass is quickly transferred into an annealing furnace at the same temperature and kept for 16 hours. After annealing, the annealing furnace is cooled to room temperature at a cooling rate of 15℃ / min.

[0076] S5, After cutting and polishing the obtained base glass, place the glass in a muffle furnace at the glass transition temperature T. g Around +50℃, from the crystallization initiation temperature T0 to the crystallization temperature T c The nucleation and crystallization processes were carried out using a synergistic process of "critical saturation nucleation & controlled growth crystallization". The temperature was raised from room temperature to 420℃ for nucleation and held for 48 hours, and then raised to 530℃ for crystallization and held for 12 hours.

[0077] S6. After the heat treatment is completed, the muffle furnace is cooled to room temperature to obtain CdS quantum dot glass.

[0078] In this embodiment, the CdS quantum dot glass exhibits an emission peak at 660 nm under 395 nm ultraviolet light excitation, with an internal quantum efficiency of 63.56%. Its luminescence intensity at 150 °C is 89.02% of that at room temperature. The Ba2SiO4:Eu... 2+ Green powder, (Sr,Ca)AlSiN3:Eu 2+The white light source is encapsulated with red powder, low melting point glass powder, 395nm LED and CdS quantum dot glass. The color coordinates of the encapsulated white light source are (0.3652, 0.3862). It has warm white light emission, color temperature CCT of 4485K, color rendering index CRI of 90.8 and luminous efficacy LE of 79.6lm / W.

[0079] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A CdS quantum dot glass, characterized by, compositions: black talc powder: 55-70wt.%; K2CO3: 5-15wt.%; Li2CO3: 5-15wt.%; SrCO3: 5-10wt.%; H3BO3: 5-20wt.%; CdS: 1-15wt.%. The content of the rare earth compound is 0-2wt.% of the total mass of the black talc powder, K2CO3, Li2CO3, SrCO3, H3BO3 and CdS; the content of the clarifying agent is 0.2-2wt.% of the total mass of the black talc powder, K2CO3, Li2CO3, SrCO3, H3BO3 and CdS. The clarifying agent is one of Sb2O3 or NaSbO3 or a combination of both. The method comprises the following steps:

2. The CdS quantum dot glass according to claim 1, wherein, The black talc powder has a particle size of 75-150 μm; and the rare earth compound is Eu2O3 or Eu2(CO3) 3， The rare earth ion is Eu 3+ .

3. The CdS quantum dot glass according to claim 1, wherein the CdS quantum dot glass is characterized by, S1, accurately weighing each raw material according to the predetermined mass percentage, grinding in an agate mortar for 0.2-4h to obtain a uniform mixture; 4. A method for preparing the CdS quantum dot glass according to any one of claims 1 to 3, characterized in that, S2, loading the obtained mixture into a corundum crucible and placing it into a melting furnace to heat from room temperature to 1100-1300℃ for 0.1-1h to obtain a glass liquid, then pouring the glass liquid into water for water quenching to obtain glass slag; S3, taking out the glass slag, washing, drying and grinding into powder; the powder is repeatedly treated 2-3 times as follows: melting in a melting furnace, water quenching to obtain glass slag, taking out the obtained slag, washing, drying and grinding into powder; finally, melting the powder in a melting furnace to obtain a uniformly melted glass liquid; S4, after the glass liquid is uniformly melted, quickly taking out the glass liquid from the melting furnace at 1100-1300℃ and pouring it onto a mold preheated to 250-330℃ for compression molding, then quickly moving the molded bulk glass into an annealing furnace at the same temperature for 5-30h of heat preservation, and cooling the annealing furnace to room temperature after annealing; S6, after the heat treatment is completed, the muffle furnace is cooled to room temperature to obtain the CdS quantum dot glass; The heating and cooling rates of the melting furnace in steps S2 and S4 are 5-30℃ / min. S5, the obtained bulk glass is cut and polished, and then placed in a muffle furnace at a glass transition temperature T g + 50°C for 12-96 h for nucleation treatment, and then kept at a temperature between a crystallization start temperature T0 and a crystallization temperature T c for 2-36 h for crystallization treatment, and the glass is subjected to nucleation and crystallization treatment by using a "critical saturation nucleation - controlled growth crystallization" synergistic process. ​ ​ 5. Use of the CdS quantum dots glass according to any one of claims 1 to 3 in a white light source, characterized in that, Several phosphors, BaMgAl 10 O 17 :Eu 2+ blue, Ba2SiO4:Eu 2+ green, (Sr,Ca)AlSiN3:Eu 2+ red, are solidified on the surface of a CdS quantum dot glass according to any one of claims 1-3 with low melting glass powder by screen printing process, and combined with LED chips to obtain white light sources.

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