Transmissive wavelength conversion device and light emitting device thereof

Abstract

The application protects a transmission type wavelength conversion device and a light emitting device using the wavelength conversion device. The transmission type wavelength conversion device comprises a light emitting glass layer, a transparent glass layer, a dielectric film and a transparent substrate which are sequentially stacked; the light emitting glass layer contains a wavelength conversion material which converts excitation light into stimulated light; the dielectric film is coated on the surface of the transparent substrate, the dielectric film transmits the excitation light and reflects the stimulated light; the transparent glass layer is arranged between the dielectric film and the light emitting glass layer. The transmission type wavelength conversion device has the characteristics of simple structure and high overall device reliability.

Description

Technical Field

[0001] This invention relates to the field of lighting and projection technology, and in particular to a transmissive wavelength conversion device and a light-emitting device employing the transmissive wavelength conversion device. Background Technology

[0002] With the development of display and lighting technologies, traditional LED or halogen bulbs are increasingly unable to meet the high power and high brightness requirements of displays and lighting. Using solid-state light sources such as LDs (Laser Diodes) to excite wavelength-converting materials can produce visible light of various colors, and this technology is increasingly being applied in lighting and displays. This technology offers advantages such as high efficiency, low energy consumption, low cost, and long lifespan, making it an ideal replacement for existing white or monochromatic light sources.

[0003] Existing laser-excited wavelength conversion materials (WCCs) typically employ reflective light sources: excitation light enters from the incident surface of the emitting layer, exciting the WCC to emit fluorescence. The fluorescence is then reflected back to the emitting layer by a reflective layer located away from the incident surface, ensuring the light returns along its original path. Reflective WCCs can generally withstand relatively high excitation power, such as 10W or more; however, their optical path design is relatively complex. In contrast, transmissive WCCs have emerged: excitation light enters from the incident surface of a transparent substrate, passes through the exit surface, and enters the emitting layer to excite the WCC to emit fluorescence. A dielectric film is placed along the incident direction of the excitation light, allowing the laser to pass through while reflecting the fluorescence, thus directing the emitted fluorescence away from the exit surface of the transparent substrate. Transmissive WCCs have a simple structure and are highly practical in laser lighting and projection applications.

[0004] Currently, the encapsulation material for the light-emitting layer in transmissive wavelength conversion devices has evolved from silicone with low heat resistance to inorganic glass. Inorganic glass has better thermal conductivity than silicone and can withstand higher temperatures. However, when the structure of a transmissive wavelength conversion device consists of a transparent substrate, a dielectric film, and a light-emitting glass layer from bottom to top, the light-emitting glass layer needs to be mechanically coated with a slurry onto the transparent substrate coated with the dielectric film. This coating process can easily damage the dielectric film, causing a decrease in wavelength selectivity. Furthermore, since the light-emitting glass layer needs to be sintered at temperatures above 400°C, this high-temperature treatment further amplifies the damage to the wavelength-selective dielectric film, resulting in poor luminous efficiency and reduced reliability of the final transmissive wavelength conversion device.

[0005] Therefore, it is necessary to develop a transmission wavelength conversion device with good light efficiency and high reliability. Summary of the Invention

[0006] To address the shortcomings of the existing technology, this invention provides a transmission wavelength conversion device with a simple structure, high luminous efficiency, and excellent reliability, suitable for laser lighting and projection applications.

[0007] The present invention provides a transmissive wavelength conversion device, comprising a light-emitting glass layer, a transparent glass layer, a dielectric film, and a transparent substrate stacked sequentially; the light-emitting glass layer contains a wavelength conversion material for converting excitation light into laser light; the dielectric film is coated on the surface of the transparent substrate for transmitting the excitation light and reflecting the laser light; the transparent glass layer is disposed between the dielectric film and the light-emitting glass layer.

[0008] In the transmissive wavelength conversion device of the present invention, excitation light is incident from the uncoated side of the transparent substrate, passes through the transparent substrate, and then passes through the dielectric film and the transparent glass layer to enter the light-emitting glass layer. Compared with the case where the light-emitting glass layer and the dielectric film are in direct contact, the transmissive wavelength conversion device of the present invention adds a transparent glass layer between the light-emitting glass layer and the dielectric film. The transparent glass layer can prevent the dielectric film from being damaged during the direct brushing of the light-emitting glass layer paste onto it and subsequent sintering, thus maintaining the excellent wavelength selectivity of the dielectric film. As a result, the entire transmissive wavelength conversion device has good luminous efficiency and excellent overall device reliability.

[0009] Preferably, the thickness of the transparent glass layer is 0.5-1 μm. Within this thickness range, the transparent glass layer protects the dielectric film without causing lateral light guide within the transparent glass layer due to excessive thickness, which would lead to an excessively large emitted light spot size and attenuation of the emitted light intensity of the luminous glass layer.

[0010] Preferably, the refractive index of the transparent glass layer is less than the refractive index of the glass in the luminescent glass layer. This arrangement enables the transmissive wavelength conversion device of the present invention to have higher light extraction efficiency and enhance the luminous intensity of the device.

[0011] Preferably, the softening point temperature of the transparent glass layer is higher than that of the luminescent glass layer. In the transmissive wavelength conversion device of the present invention, the transparent glass layer and the luminescent glass layer are typically prepared by sequential, two-stage high-temperature sintering. By selecting appropriate glass powder, the softening point temperature of the transparent luminescent glass layer is made higher than that of the luminescent glass layer, ensuring that the transparent glass layer does not melt during the sintering process to obtain the luminescent glass layer, thereby better protecting the dielectric film.

[0012] Preferably, the luminescent glass layer further contains scattering particles. The scattering particles can be one or both of Al2O3 and TiO2. The addition of scattering particles enhances the scattering of incident light and laser light by the luminescent glass layer, improving the color temperature consistency of the device and solving the problem of blue light leakage. More preferably, when the scattering particles are Al2O3, the addition amount is preferably 0.5–10 wt% of the weight of the luminescent glass layer, and the particle size is preferably 0.01–1 μm; when the scattering particles are TiO2, the addition amount is preferably 0.01–1 wt% of the weight of the luminescent glass layer, and the particle size is preferably 0.01–1 μm; when the scattering particles are both Al2O3 and TiO2, the particle size of the Al2O3 scattering particles is preferably 0.01–1 μm, and the addition amount is preferably 0.5–4 wt%, while the particle size of the TiO2 scattering particles is preferably 0.01–1 μm, and the addition amount is preferably 0.01–0.5 wt%.

[0013] Preferably, the transparent substrate can be transparent glass or transparent ceramic, and sapphire is preferred as the transparent substrate. Sapphire has the characteristics of high thermal conductivity and high mechanical strength. In some embodiments, a thinner sapphire is used as the transparent substrate, preferably 0.1-1 mm thick, more preferably 0.2-0.5 mm. In this case, the sapphire transparent substrate can reduce the light transmission loss in the transparent substrate while ensuring sufficient strength.

[0014] The present invention also provides a light-emitting device, including an excitation light source and the above-mentioned transmissive wavelength conversion device, which is suitable for the fields of lighting and projection.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] In the transmissive wavelength conversion device of this invention, a dielectric film is deposited on a transparent substrate. The dielectric film transmits excitation light and reflects the laser light. The performance of the dielectric film plays a crucial role in the overall luminous effect of the device. Compared with the technical solution where the luminescent glass layer is directly placed on the dielectric film, this invention adds a transparent glass layer between the luminescent glass layer and the dielectric film. The transparent glass layer covers the dielectric film, protecting it from mechanical damage caused by the brushing of the luminescent glass layer paste, resulting in better luminous efficiency and superior reliability of the entire device. Attached Figure Description

[0017] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

[0018] Figure 1 This is a schematic diagram of the structure of the transmission wavelength conversion device according to Embodiment 1 of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the transmission wavelength conversion device according to Embodiment 2 of the present invention. Detailed Implementation

[0020] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and descriptions.

[0021] As described in the background section, transmissive wavelength conversion devices, with their simple structure, have excellent application prospects in laser lighting and projection. However, current techniques for preparing the luminescent layer by directly coating a dielectric film have the problem of easily causing mechanical damage to the dielectric film during coating, thus compromising its performance and ultimately resulting in poor luminescence performance of the device. Therefore, this invention adds a glass layer to the dielectric film, and the luminescent layer paste is applied to the glass layer, thereby protecting the dielectric film.

[0022] Please refer to Figure 1 The present invention provides a transmissive wavelength conversion device 100, which includes a light-emitting glass layer 104, a transparent glass layer 103, a dielectric film 102 and a transparent substrate 101 stacked in sequence.

[0023] The light-emitting glass layer 104 contains a wavelength conversion material, which is used to convert the excitation light incident on the light-emitting glass layer 104 into laser light. A dielectric film 102 is deposited on the transparent substrate 101. The dielectric film 102 is used to transmit the excitation light passing through the transparent substrate 101 and reflect the laser light incident from the light-emitting glass layer 104 onto the dielectric film 102. A transparent glass layer 103 is disposed between the transparent substrate 101 and the light-emitting glass layer 104 on which the dielectric film 102 is deposited. The area of ​​the transparent glass layer 103 is usually larger than the area of ​​the dielectric film 102. The transparent glass layer 103 completely covers the dielectric film 102 in order to better protect the dielectric film 102.

[0024] In practical applications, the transmissive wavelength conversion device 100 involves excitation light entering from the side of the transparent substrate 101 away from the dielectric film 102, passing through the transparent substrate 101, the dielectric film 102, and the transparent glass layer 103 before entering the light-emitting glass layer 104, where wavelength conversion is achieved. Here, the dielectric film 102 reflects the laser light through the excitation light, allowing the excitation light, which is received by the laser and / or directly transmitted, to exit from the side of the self-emitting glass layer 104 away from the transparent substrate 101.

[0025] In this invention, the luminescent glass layer 104 comprises a wavelength conversion material. This wavelength conversion material receives incident excitation light and emits laser light. The composition of the wavelength conversion material is not particularly limited; for example, it can be one of aluminate phosphor, halophosphate phosphor, garnet-based phosphor, or quantum dots. In some embodiments, when using a blue laser as the excitation light, the wavelength conversion material can be a yellow phosphor, such as YAG:Ce phosphor. It should be noted that the thickness of the luminescent glass layer 104 needs to balance the sufficient absorption of the excitation light by the wavelength conversion material and the light emission efficiency. Preferably, the thickness of the luminescent glass layer 104 is 30-200 μm, which can be achieved by adjusting the consistency of the slurry and the application pressure.

[0026] In this invention, the transparent glass layer 103 is applied to the surface of the transparent substrate 101 coated with the dielectric film 102 by a glass slurry coating process using a spin coating method. Regarding the areas of both the transparent glass layer 103 and the dielectric film 102, both in terms of the spin coating process of the transparent glass layer 103 onto the dielectric film 102 and the desired protective effect of the transparent glass layer 103, the area of ​​the transparent glass layer 103 is typically larger than the area of ​​the dielectric film 102, and the transparent glass layer 103 completely covers the dielectric film 102. As for the thickness of the transparent glass layer 103, it can be controlled by adjusting the spin coating speed and time during the spin coating process. The thickness of the transparent glass layer 103 is preferably 0.5-1 μm. If the thickness is too thin, less than 0.5 μm, the dielectric film 102 may not be fully covered in some areas, and the strength of the transparent glass layer 103 may be insufficient. The protective effect of the transparent glass layer 103 on the dielectric film 102 will be greatly reduced. If the thickness is too thick, greater than 1 μm, the laser reflected by the dielectric film 102 may be guided laterally within the transparent glass layer 103, resulting in an excessively large outgoing light spot size and attenuation of illuminance.

[0027] In this invention, there are two sintering processes for the transparent glass layer 103 and the light-emitting glass layer 104: (1) After the transparent substrate 101 is pre-coated with a dielectric film 102, the transparent glass layer 103 slurry is attached to the dielectric film 102 by spin coating, pre-sintering and drying, so that the transparent glass layer 103 and the coated substrate form a certain strength bond; then, the light-emitting glass layer 104 slurry is brushed onto the surface of the transparent glass layer 103, pre-sintering and drying; finally, they are placed together in an air atmosphere furnace for high-temperature sintering, so as to achieve a firm bond between the light-emitting glass layer 104, the transparent glass layer 103 and the coated substrate, and obtain the transmissive wavelength conversion device of this invention. (2) In another case, after the transparent substrate 101 is pre-coated with a dielectric film 102, the transparent glass layer 103 slurry is coated on the coated surface of the transparent substrate 101 by spin coating. First, a high-temperature sintering is performed to make the transparent glass layer 103 firmly bonded to the coated surface of the transparent substrate 101. Then, the slurry of the light-emitting glass layer 104 is brushed on the surface of the transparent glass layer 103 and then a high-temperature sintering is performed to make the light-emitting glass layer 104 firmly bonded to the surface of the transparent glass layer 103, thus obtaining the transmissive wavelength conversion device of the present invention.

[0028] In the two sintering processes described above, especially for the second sintering process, it is preferable that the softening point temperature of the transparent glass layer 103 is higher than that of the light-emitting glass layer 104. In this case, the transparent glass layer 103 will not melt during the sintering of the light-emitting glass layer 104, thereby better protecting the dielectric film 102. On the other hand, it is preferable that the refractive index of the transparent glass layer 103 is lower than that of the encapsulating glass of the light-emitting glass layer 104. In this case, the laser light can more easily enter the light-emitting glass layer 104 from the transparent glass layer 103, giving the transmissive wavelength conversion device of the present invention a higher light extraction efficiency and enhancing the luminous intensity of the device.

[0029] In this invention, the luminescent glass layer 104 preferably also contains scattering particles of one or both of Al2O3 and TiO2. Due to limitations such as the different particle sizes of the encapsulating glass powder and the wavelength conversion material, the thickness of the luminescent glass layer 104 itself, and the coating process, the distribution of the wavelength conversion material in the coated luminescent glass layer 104 is not uniform, easily leading to localized areas with little or no wavelength conversion material. Furthermore, when the excitation light is blue laser, the laser spot is very small, thus there is a high probability that the luminescent glass layer 104 area irradiated by the laser spot will have little or no wavelength conversion material. When there is little or no wavelength conversion material in the irradiated area, more blue light is transmitted, resulting in localized blue light leakage and uneven spot distribution. By adding scattering particles to the luminescent glass layer 104, the excitation light can be dispersed and its propagation path altered, resulting in a relatively uniform excitation light distribution. Even if there is little or no wavelength conversion material in localized areas of the luminescent glass layer 104, the more dispersed and larger excitation light spot results in a more uniform spot with better color temperature consistency.

[0030] For Al2O3 scattering particles, the preferred addition amount is 0.5–10 wt% of the weight of the luminescent glass layer 104, and the preferred particle size is 0.01–1 μm. Due to the refractive index difference between Al2O3 scattering particles (refractive index 1.7–1.8) and glass powder (e.g., refractive index 1.5) and wavelength conversion materials (e.g., yellow phosphor with a refractive index of 1.7–1.8), scattering occurs when excitation light irradiates the scattering particles inside the luminescent glass layer 104. For TiO2 scattering particles, the refractive index difference between TiO2 particles (refractive index 2.6) and glass powder and wavelength conversion materials is greater than that between Al2O3 particles; the luminescent glass layer 104 with added TiO2 scattering particles has a stronger scattering effect on excitation light, and a small amount can play a role in adjusting color temperature consistency and changing the uniformity of light spot; in this invention, the preferred addition amount of TiO2 scattering particles is 0.01–1 wt% of the weight of the luminescent glass layer 104, and the preferred particle size is 0.01–1 μm. The particle size range of the scattering particles in this invention refers to the range of their average particle size D50.

[0031] In another embodiment of the present invention, Al2O3 and TiO2 scattering particles are added to the light-emitting glass layer 104 to further enhance the scattering of excitation light in the light-emitting glass layer 104, making the propagation path of the excitation light more complex and the laser excitation area larger; at this time, the amount of Al2O3 scattering particles added is preferably 0.5-4 wt%, the amount of TiO2 scattering particles added is preferably 0.01-0.5 wt%, and the particle size of both is preferably 0.01-1 μm.

[0032] In this invention, the transparent substrate 101 can be transparent glass or transparent ceramic with high excitation light transmittance and certain mechanical strength. In some embodiments, sapphire is preferred as the transparent substrate 101, considering that sapphire also has the characteristics of high thermal conductivity, good mechanical properties, and easy processing. In addition, reducing the thickness of the sapphire transparent substrate 101 can reduce the transmission loss of excitation light therein. However, if the thickness of the sapphire transparent substrate 101 is too thin, its mechanical strength will decrease, making it difficult to operate in practice. Therefore, the thickness of the sapphire transparent substrate 101 is preferably 0.1-1 mm, more preferably 0.2-0.5 mm. For the dielectric film 102 deposited on the transparent substrate 101, conventional deposition methods can be used. The dielectric film 102 is preferably a film system that is resistant to high temperature and high laser power.

[0033] The present application will be further described in detail below through specific embodiments. The following embodiments are only for further illustration of the present application and should not be construed as limiting the present application.

[0034] Example 1

[0035] like Figure 1 As shown, the structure of the transmissive wavelength conversion device 100 in Embodiment 1 of the present invention consists of a light-emitting glass layer 104, a transparent glass layer 103, a dielectric film 102 and a transparent substrate 101 stacked sequentially.

[0036] The luminescent glass layer 104 is formed by sintering a mixture of glass powder and phosphor. The phosphor is a yellow phosphor, such as YAG:Ce yellow phosphor. The thickness of the luminescent glass layer 104 is approximately 30-200 μm. The transparent substrate 101 is a sapphire transparent substrate with a thickness of approximately 0.2 mm. The dielectric film 102 deposited on the sapphire transparent substrate 101 is a bluepass film, and the corresponding excitation light is laser blue light. Figure 1 As shown, blue laser light is incident from the non-coated surface of the sapphire transparent substrate 101, passes through the bluepass film 102 and the transparent glass layer 103, and is incident on the light-emitting glass layer 104. The blue laser light excites yellow fluorescence inside the light-emitting glass layer 104. The fluorescence is reflected back to the light-emitting glass layer 104 through the bluepass film 102. After being combined with the blue laser light that has not undergone wavelength conversion to form white light, the self-emitting glass layer 104 is emitted away from the surface of the transparent substrate 101.

[0037] In this embodiment, the fabrication process of the transmissive wavelength conversion device 100 is as follows: a sapphire transparent substrate 101 with a thickness of approximately 0.2 mm is prepared; a bluepass film 102 is deposited on one surface of the sapphire transparent substrate 101; a slurry of a transparent glass layer 103 is then applied to the coated surface of the sapphire transparent substrate 101 by spin coating, followed by pre-sintering and drying to ensure a certain strength bond between the transparent glass layer 103 and the coated sapphire; subsequently, a slurry of a light-emitting glass layer 104 is applied to the surface of the transparent glass layer 103, followed by pre-sintering and drying; finally, high-temperature sintering is performed in an air atmosphere furnace to achieve a firm bond between the light-emitting glass layer 104, the transparent glass layer 103, and the coated sapphire transparent substrate 101, thus obtaining the transmissive wavelength conversion device 100. The area of ​​the transparent glass layer 103 is larger than the area of ​​the bluepass film 102, and the area of ​​the light-emitting glass layer 104 can be further selected to be larger than the area of ​​the transparent glass layer 103. It should be noted that... Figure 1 This is to visually represent the relative sizes of the luminescent glass layer 104, the transparent glass layer 103, and the bluepass film 102. In reality, the luminescent glass layer 104 completely covers the transparent glass layer 103, and the transparent glass layer 103 completely covers the bluepass film 102. The excess area falls on and adheres to the sapphire transparent substrate 101. This completely covered structure better protects the film layers from damage.

[0038] For the transparent glass layer 103, its thickness can be controlled by adjusting the spin speed and time of the spin coating. The preferred thickness is 0.5-1 μm. If the thickness is too thin, the coating will not be fully covered in some areas, and the transparent glass layer 103 will not be strong enough to protect the film. If the thickness is too thick, the fluorescence reflected by the bluepass film 102 will be guided laterally when passing through the transparent glass layer 103, resulting in an excessively large fluorescence spot size and attenuation of illuminance. For the luminescent glass layer 104, its thickness can be controlled by adjusting the consistency of the slurry and the coating pressure. The preferred thickness of the luminescent glass layer 104 is 30-200 μm.

[0039] In other embodiments of the present invention, different methods are used to prepare the transmissive wavelength conversion device. The main difference is that: after the slurry of the transparent glass layer 103 is coated onto the coated surface of the sapphire transparent substrate 101 by spin coating, it is sintered at high temperature, so that the transparent glass layer 103 is firmly bonded to the sapphire transparent substrate 101; then the slurry of the light-emitting glass layer 104 is brushed onto the surface of the transparent glass layer 103 after high-temperature sintering, and a second high-temperature sintering is performed, so that the light-emitting glass layer 104 is firmly bonded to the surface of the transparent glass layer 103, thus obtaining the transmissive wavelength conversion device.

[0040] For the two preparation processes described above, especially the process of separately sintering the transparent glass layer 103 and the luminescent glass layer 104 at high temperatures, the softening point temperature of the glass powder in the transparent glass layer 103 should be higher than that in the luminescent glass layer 104. This ensures that the transparent glass layer 103 will not melt during the high-temperature sintering of the luminescent glass layer 104, thus better protecting the dielectric film 102. On the other hand, the refractive index of the glass powder in the transparent glass layer 103 is lower than that of the glass in the luminescent glass layer 104. This configuration allows the device to have higher light extraction efficiency and enhance the luminous intensity of the device.

[0041] Example 2

[0042] like Figure 2 As shown, the transmissive wavelength conversion device 200 of Embodiment 2 of the present invention is similar to the transmissive wavelength conversion device 100 in Embodiment 1, also including a light-emitting glass layer 204, a transparent glass layer 203, a bluepass film 202, and a sapphire transparent substrate 201. The difference from Embodiment 1 is that, in addition to the wavelength conversion material 2041, the light-emitting glass layer 204 also contains Al2O3 scattering particles 2042 and TiO2 scattering particles 2043. By adding Al2O3 and TiO2 scattering particles to the light-emitting glass layer 204, excitation light and laser light can be scattered, resulting in a more uniform final light spot and better color temperature consistency.

[0043] In this embodiment, the amount of Al2O3 scattering particles 2042 added is 0.5–4 wt%, and the amount of TiO2 scattering particles 2043 added is 0.01–0.5 wt%, with both having a particle size of 0.01–1 μm. It is readily understood that the scattering particles added to the luminescent glass layer 204 may also consist of only Al2O3 scattering particles 2042 or TiO2 scattering particles 2043.

[0044] This invention also provides a light-emitting device, which includes an excitation light source and a transmissive wavelength conversion device, wherein the transmissive wavelength conversion device can have the structure and function described in the above embodiments. This light-emitting device can be applied to projection systems, such as liquid crystal display (LCD) or digital light processor (DLP) projectors; it can also be applied to lighting systems, such as automotive headlights or stage lights; and it can also be applied in the field of 3D display technology.

[0045] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0046] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A transmission-type wavelength conversion device, characterized in that, It includes a light-emitting glass layer, a transparent glass layer, a dielectric film, and a transparent substrate stacked sequentially; The light-emitting glass layer contains a wavelength conversion material that converts excitation light into laser light. The dielectric film is deposited on the surface of the transparent substrate, and the dielectric film transmits the excitation light and reflects the laser light. The transparent glass layer is disposed between the dielectric film and the light-emitting glass layer; The thickness of the transparent glass layer is 0.5-1 μm; The area of ​​the transparent glass layer is larger than the area of ​​the dielectric film, and the transparent glass layer completely covers the dielectric film; the area of ​​the transparent glass layer that exceeds the dielectric film falls on the transparent substrate and is bonded to the transparent substrate. The area of ​​the light-emitting glass layer is larger than the area of ​​the transparent glass layer; and the light-emitting glass layer completely covers the transparent glass layer, with the area of ​​the light-emitting glass layer that extends beyond the transparent substrate falling on the transparent substrate and being bonded to the transparent substrate. The refractive index of the transparent glass layer is less than the refractive index of the glass in the light-emitting glass layer; The softening point temperature of the transparent glass layer is greater than that of the luminescent glass layer.

2. The transmissive wavelength conversion device according to claim 1, characterized in that, The luminescent glass layer also contains scattering particles.

3. The transmissive wavelength conversion device according to claim 2, characterized in that, The scattering particles are one or both of Al2O3 and TiO2.

4. The transmissive wavelength conversion device according to claim 3, characterized in that, The particle size of the scattering particles is 0.01-1 μm.

5. A transmission-type wavelength conversion device according to claim 4, characterized in that, The scattering particles are Al2O3, and the amount added is 0.5-10 wt%.

6. A transmission-type wavelength conversion device according to claim 4, characterized in that, The scattering particles are TiO2, and the amount added is 0.01-1 wt%.

7. A transmission-type wavelength conversion device according to claim 4, characterized in that, The scattering particles are Al2O3 and TiO2, with the amount of Al2O3 scattering particles added being 0.5–4 wt% and the amount of TiO2 scattering particles added being 0.01–0.5 wt%.

8. The transmission wavelength conversion device according to claim 1, characterized in that, The transparent substrate is a sapphire transparent substrate.

9. A transmission-type wavelength conversion device according to claim 8, characterized in that, The thickness of the sapphire transparent substrate is 0.2-0.5 mm.

10. A method for fabricating a transmission-type wavelength conversion device, characterized in that, The process includes the following steps: After the transparent substrate is pre-coated with a dielectric film, the transparent glass layer paste is attached to the dielectric film by spin coating, and then pre-sintered and dried or subjected to a high-temperature sintering to form an adhesion between the transparent glass layer and the coated substrate; then, the light-emitting glass layer paste is applied to the surface of the transparent glass layer, and after pre-sintering and drying, it is sintered at high temperature or directly sintered at high temperature to achieve the bonding of the light-emitting glass layer, the transparent glass layer and the transparent substrate coated with the dielectric film. The thickness of the transparent glass layer is 0.5-1 μm; the area of ​​the transparent glass layer is larger than the area of ​​the dielectric film, and the transparent glass layer completely covers the dielectric film; the area of ​​the transparent glass layer that extends beyond the dielectric film falls on the transparent substrate and is bonded to the transparent substrate. The area of ​​the transparent glass layer is larger than the area of ​​the dielectric film, and the area of ​​the light-emitting glass layer is larger than the area of ​​the transparent glass layer; and the light-emitting glass layer completely covers the transparent glass layer, the transparent glass layer completely covers the dielectric film, and the area of ​​the light-emitting glass layer that exceeds the transparent substrate falls on the transparent substrate and is bonded to the transparent substrate; The refractive index of the transparent glass layer is less than the refractive index of the glass in the light-emitting glass layer; The softening point temperature of the transparent glass layer is greater than that of the luminescent glass layer.

11. A light-emitting device, comprising an excitation light source and a transmissive wavelength conversion device as described in any one of claims 1-9.

Images