Composite optical glass, method for producing the same, and use thereof

Abstract

The present application relates to the technical field of photoelectric packaging and thermal management materials, and particularly relates to a composite optical glass, a preparation method and application thereof. The composite optical glass comprises a glass substrate, a first composite optical film layer and a second composite optical film layer arranged on two main surfaces of the glass substrate respectively, the average transmittance of the composite optical glass to visible light with a wavelength of 0.38-0.78 microns is greater than 90%, the weighted solar average reflectivity in the wavelength range of 0.8-2.5 microns is greater than 70%, and the emissivity in the wavelength range of 8-13 microns is greater than or equal to 80%. The composite optical glass can efficiently reflect near-infrared heat while maintaining extremely high visible light transmittance, and meanwhile, high emission in the mid-infrared band is achieved.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic packaging and thermal management materials technology, and in particular to a composite optical glass, its preparation method and application. Background Technology

[0002] High-power LED chips are widely used in lighting and display fields, but they generate a large amount of heat during operation, especially from near-infrared thermal radiation. Failure to effectively manage this thermal radiation will lead to increased chip junction temperature, decreased luminous efficiency, and reduced lifespan, severely limiting the improvement of LED device performance. Therefore, developing a spectrally selective functional material that can effectively manage the thermal radiation of LED chips is of great value for improving the reliability of LED devices.

[0003] Currently, LED packaging heat dissipation mainly relies on active cooling methods such as metal heat sinks or fans, but these solutions suffer from problems such as large size, high cost, and low reliability. Optical film-based heat dissipation, as a passive thermal management technology, has attracted attention in recent years. The mainstream film structures are mainly divided into two categories: The first is the "dielectric / metal / dielectric" structure. This structure relies on an ultra-thin metal layer to achieve spectral selectivity and can reflect near-infrared thermal radiation, but it has extremely stringent requirements for the deposition process, is costly, and the metal layer has long-term stability and weather resistance issues, limiting its application in LED packaging. The second category is the "all-dielectric multilayer film" structure. Although this structure avoids the disadvantages of metal materials, to achieve efficient spectral control across a wide band, the total film thickness usually needs to exceed 5μm, leading to stress accumulation within the film layer and easily causing problems such as interface cracking and delamination, making it difficult to guarantee reliability under the high-temperature thermal cycling environment of LED packaging.

[0004] Therefore, existing technologies need to be improved. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a composite optical glass, its preparation method and application. The composite optical glass of this invention can efficiently reflect near-infrared heat while maintaining extremely high visible light transmittance, and at the same time achieve high emission in the mid-infrared band. It solves the stress failure problem caused by excessive thickness of traditional all-dielectric films, as well as the cost and stability problems of metal-based film layers.

[0006] The technical solution of the present invention is as follows: In a first aspect, the present invention provides a composite optical glass, comprising a glass substrate and a first composite optical film layer and a second composite optical film layer respectively disposed on both sides of the main surface of the glass substrate. The composite optical glass has an average transmittance of more than 90% for visible light with wavelengths from 0.38μm to 0.78μm, a weighted average solar reflectance of more than 70% in the 0.8μm to 2.5μm band, and an emissivity of more than or equal to 80% in the 8-13μm band.

[0007] Optionally, the first composite optical film layer (2) is formed by alternating stacking of multiple low-refractive-index material layers and multiple high-refractive-index material layers from the inside out; The second composite optical film layer (3) is composed of multiple low-refractive-index material layers and multiple high-refractive-index material layers stacked alternately from the inside out; or, The first composite optical film layer (2) is formed by alternating stacking of a high-low refractive index material layer and multiple low refractive index material layers from the inside out; The second composite optical film layer (3) is formed by alternating stacking of multiple high refractive index material layers and multiple low refractive index material layers from the inside out.

[0008] Optionally, the total physical thickness of the first composite optical film layer is 1-5µm, and it is composed of 10 to 30 alternately stacked low-refractive-index material layers and multiple high-refractive-index material layers.

[0009] Optionally, the total physical thickness of the second composite optical film layer is 1µm to 3µm, and it is composed of 10 to 20 alternately stacked low-refractive-index material layers and multiple high-refractive-index material layers.

[0010] Optionally, the material of the low refractive index material layer is selected from one or more of MgF2, SiO2, YF3, and CaF2.

[0011] Optionally, the material of the high refractive index material layer is selected from one or more of TiO2, Nb2O5, ZrO2, and Ta2O5.

[0012] Optionally, the glass substrate is soda-lime glass, alkaline aluminosilicate glass, alkaline borosilicate glass, or alkaline aluminosilicate glass.

[0013] Secondly, the present invention provides a method for preparing composite optical glass, comprising the following steps: S1. Provide a glass substrate; S2. A first composite optical film layer is deposited on the first side of the glass substrate using a thermal evaporation process assisted by ion beam deposition. S3. A second composite optical film layer is deposited on the second surface of the glass substrate using a thermal evaporation process assisted by ion beam deposition.

[0014] Optionally, the thermal evaporation process for ion beam-assisted deposition can be performed at a vacuum level not exceeding 2.0 × 10⁻⁶. -3 It takes place in the chamber of Pa.

[0015] Optionally, when depositing the first composite optical film or the second composite optical film, the deposition rate is controlled between 0.5 nm / s and 1.5 nm / s.

[0016] It should be noted that the thickness of each layer in the first and second composite optical film layers in this embodiment is designed by an optimization algorithm. The optimization algorithm is selected from at least one of particle swarm optimization, genetic algorithm, and simulated annealing algorithm. The optimization objective is to make the composite optical glass satisfy the following: the weighted average solar reflectivity in the 0.8μm to 2.5μm band is greater than 70%, and the emissivity in the 8-13μm band is greater than or equal to 80%.

[0017] Thirdly, the present invention provides an optical device comprising the aforementioned composite optical glass.

[0018] Optionally, the optical device is an LED package heat dissipation assembly.

[0019] Beneficial Effects: This invention provides a composite optical glass, its preparation method, and its application. The invention assembles a composite optical glass by respectively depositing a first composite optical film layer and a second composite optical film layer on both sides of the main surface of a glass substrate. This results in a weighted average solar reflectivity greater than 70% in the 0.8μm to 2.5μm wavelength range and an emissivity greater than or equal to 80% in the 8-13μm wavelength range. This allows the composite optical glass to maintain extremely high visible light transmittance while efficiently reflecting near-infrared heat and simultaneously achieving high emissivity in the mid-infrared band. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the MgF2 / Ta2O5 double-sided high-transparency composite heat-insulating glass provided in Embodiment 1 of the present invention.

[0021] Figure 2 This is a spectral diagram of the MgF2 / Ta2O5 double-sided high-transparency composite heat-insulating glass provided in Embodiment 1 of the present invention.

[0022] Figure 3 This is a schematic diagram of the SiO2 / TiO2 double-sided high-transparency composite heat-insulating glass provided in Embodiment 2 of the present invention.

[0023] Figure 4 This is a schematic diagram of the spectrum of the SiO2 / TiO2 double-sided high-transparency composite heat-insulating glass provided in Embodiment 2 of the present invention.

[0024] Figure 5 The images show photographs and infrared images of the composite glass used for cooling LED light panels in Embodiment 3 of the present invention.

[0025] Figure 6This is a schematic diagram of the MgF2 / Ta2O5 single-sided high-transparency composite heat-insulating glass provided in Comparative Example 2 of the present invention.

[0026] Figure 7 This is a schematic diagram of the spectrum of the MgF2 / Ta2O5 single-sided high-transparency composite heat-insulating glass provided in Comparative Example 2 of the present invention. Detailed Implementation

[0027] This invention provides a composite optical glass, its preparation method, and its applications. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0028] High-power LED chips, with their outstanding advantages such as high efficiency and energy saving, long lifespan, small size, and fast response speed, have been widely used in many core fields such as general lighting, outdoor displays, automotive lighting, and industrial lighting. Furthermore, with technological iterations, their power density and integration have continuously improved, further driving the upgrading of the lighting and display industry. However, high-power LED chips suffer from significant energy loss during operation. Their electro-optical conversion efficiency is typically only 30%-50%, with most of the remaining energy released as heat. Near-infrared radiation (0.8μm-2.5μm) is one of the main sources of this heat generation.

[0029] Effective control of thermal radiation directly determines the core performance and lifespan of high-power LED devices. When the near-infrared thermal radiation generated by the chip cannot dissipate in time, the chip junction temperature rises rapidly. On the one hand, this leads to a decrease in the chip's internal quantum efficiency, resulting in problems such as luminous efficacy decay, color temperature drift, and a reduction in the color rendering index, affecting lighting and display effects. On the other hand, prolonged high-temperature environments accelerate the aging of chip packaging materials (such as encapsulating adhesive, gold wire, and substrate), causing packaging structure failure and significantly shortening the lifespan of LED devices. In severe cases, it can even cause the chip to burn out. This has become a core technological bottleneck restricting the development of high-power LEDs towards higher power, smaller size, and longer-term stable operation. Therefore, developing a spectrally selective functional material that combines high visible light transmittance, efficient near-infrared thermal radiation reflection, and efficient mid-infrared heat dissipation to achieve precise control of LED chip thermal radiation has significant engineering application value and industry promotion significance for overcoming existing technological limitations and improving the reliability and lifespan of high-power LED devices.

[0030] Currently, the industry primarily uses active cooling for thermal management of high-power LED packaging. This relies on devices such as metal heat sinks, cooling fans, and heat pipes to transfer heat generated by the chip to the external environment through heat conduction and convection. However, this type of active cooling solution has several inherent drawbacks: metal heat sinks and cooling fans are bulky, making them difficult to adapt to the miniaturized and integrated LED packaging requirements, especially limiting their application in high-density LED display modules and micro-automotive lighting. Furthermore, the introduction of active cooling components not only increases the overall cost of LED devices but also introduces reliability risks such as fan wear and heat pipe leakage, requiring additional maintenance costs and failing to meet the demands of long-term stable operation.

[0031] To address the inherent drawbacks of active heat dissipation, optical film-based heat dissipation, as a passive thermal management technology, has gradually become a research hotspot in the field of high-power LED thermal management in recent years due to its advantages such as small size, zero energy consumption, high reliability, and integration with packaging structures. Currently, mainstream optical film-based heat dissipation structures are mainly divided into two categories, but both have insurmountable technical defects that cannot meet the practical application requirements of high-power LED packaging.

[0032] The first type is the "dielectric / metal / dielectric" (D / M / D) composite film structure. This structure uses an ultrathin metal layer (such as silver, gold, aluminum, etc.) as the core functional layer. It utilizes the high reflectivity of metal materials in the near-infrared band to block near-infrared thermal radiation. At the same time, the dielectric layers on both sides protect the metal layer and reduce the absorption of visible light by the metal layer, ensuring the light extraction efficiency of the LED. However, this structure has obvious limitations: the deposition process of the ultrathin metal layer requires extremely stringent conditions, and the thickness of the metal layer must be precisely controlled at the nanometer level. Otherwise, problems such as metal layer oxidation and crystallization defects are prone to occur, leading to a decrease in near-infrared reflectivity. Moreover, the metal material itself has insufficient long-term stability and poor weather resistance. In the high-temperature and humid working environment of LED packaging, the metal layer is prone to oxidation and corrosion, which leads to film peeling and optical performance degradation, seriously affecting the long-term reliability of LED devices. In addition, the use of precious metal materials also significantly increases the preparation cost of the film system, limiting its application in large-scale industrial production.

[0033] The second type is the all-dielectric multilayer film structure. This structure uses alternating stacks of low-refractive-index and high-refractive-index dielectric materials, completely avoiding the use of metal materials and effectively solving the problems of poor stability and high cost of metal layers. However, to achieve broadband near-infrared reflection and mid-infrared emission modulation, this structure needs to increase the number of film layers and the total thickness of the film system to broaden the spectral modulation range. Typically, the total thickness of the film system needs to exceed 5μm. The increase in the total thickness of the film system leads to a sharp accumulation of internal stress, and the difference in thermal expansion coefficients between different film layers will further aggravate stress concentration. Under the high-temperature thermal cycling environment of high-power LED packaging, it is very easy to cause failure phenomena such as interface cracking and delamination between the film layer and the glass substrate, and between film layers, resulting in the loss of optical performance of the film system and failing to guarantee the long-term stable operation of the LED device.

[0034] In summary, existing high-power LED thermal radiation management solutions all have significant technical shortcomings. Active heat dissipation solutions are bulky, costly, and have low reliability, while passive optical film-based heat dissipation solutions either have issues with the stability and cost of the metal layer or stress failure due to excessive film thickness. Neither can achieve the synergistic goal of "high visible light transmittance, efficient near-infrared reflection, high mid-infrared emission, stable film layer, and controllable cost".

[0035] Therefore, in order to address the shortcomings of existing technologies, developing a novel composite optical material and its preparation method to solve the core pain point of thermal radiation management of high-power LED chips has become a technical problem that urgently needs to be solved by those skilled in the art.

[0036] Based on this, this embodiment provides a composite optical glass, including a glass substrate 1 and a first composite optical film layer 2 and a second composite optical film layer 3 respectively disposed on the main surfaces of both sides of the glass substrate 1. The composite optical glass has an average transmittance of more than 90% for visible light with wavelengths from 0.38μm to 0.78μm, a weighted average solar reflectance of more than 70% in the 0.8μm to 2.5μm band, and an emissivity of more than or equal to 80% in the 8-13μm band.

[0037] The composite optical film layer 2 is composed of multiple low-refractive-index material layers and multiple high-refractive-index material layers stacked alternately from the inside out; The composite optical film layer 3 is composed of multiple low-refractive-index material layers and multiple high-refractive-index material layers stacked alternately from the inside out.

[0038] Specifically: In this embodiment, the glass substrate 1 serves as the supporting carrier for the entire composite optical glass. It has a flat sheet structure, and its two opposing main surfaces generally need to be polished to ensure surface flatness and ensure the uniformity of the film layer. The first composite optical film layer 2 and the second composite optical film layer 3 completely cover the two sides of the glass substrate 1, respectively. The film layer and the substrate are tightly bonded together without obvious gaps or defects, forming an integrated "substrate-film layer" structure. The overall structure is compact and the thickness is controllable. In this embodiment, the composite optical glass utilizes the selective reflection of the near-infrared band (0.8μm-2.5μm) by the first composite optical film layer 2 and the second composite optical film layer 3. Through the multi-beam interference effect between the film layers, it reflects the near-infrared thermal radiation generated by the LED chip back to the heat source side, reducing heat conduction and accumulation to the outside. For the high emission characteristics of the mid-infrared band (8-13μm, atmospheric window band), based on Kirchhoff's thermal radiation law (emissivity equals absorptivity under thermal equilibrium), it efficiently dissipates the heat absorbed by the glass substrate and film layers into the atmosphere in the form of infrared radiation. At the same time, both the glass substrate and the two composite optical film layers are made of low visible light absorption materials to ensure that visible light can pass through efficiently without affecting the light output performance of the LED device. Ultimately, it achieves a synergistic effect of "high near-infrared reflectivity, high mid-infrared emissivity, and high visible light transmittance." Specifically, the weighted average solar reflectivity in the 0.8μm to 2.5μm band is ≥70%, which can effectively block near-infrared thermal radiation generated by LED chips and reduce heat accumulation; the emissivity in the 8-13μm band is ≥80%, which can quickly radiate and dissipate absorbed heat, significantly reducing the junction temperature of LED chips; at the same time, it avoids the use of metal film layers, eliminating metal oxidation and corrosion problems, and also solves the drawbacks of excessive thickness in traditional all-dielectric films. The overall optical performance is stable, the service life is long, and it is suitable for the use requirements of high-power LED packaging.

[0039] Moreover, both the first composite optical film layer 2 and the second composite optical film layer 3 are all-dielectric multilayer interference film structures. From the surface of the glass substrate outward, they are composed of alternating stacks of low-refractive-index material layers and high-refractive-index material layers, or alternating stacks of high-refractive-index material layers and low-refractive-index material layers, forming stacked units with alternating high and low refractive indices. The interfaces between adjacent film layers are clear, there is no interdiffusion of elements, and the film layers are dense and uniform. Both the low-refractive-index material layer and the high-refractive-index material layer are transparent dielectric layers with no metal components, and their thickness is controlled at the nanometer to submicrometer level to ensure that the film layers are thin and light overall. By utilizing the refractive index difference between the low-refractive-index material layer and the high-refractive-index material layer, Fresnel reflection is generated at the interfaces of each film layer when incident light is incident. By rationally designing the film layer thickness, constructive interference is generated in the reflected light in the near-infrared band, thereby enhancing the near-infrared reflection capability of the first composite optical film layer 2. At the same time, by optimizing the stacking period and film layer thickness, constructive interference absorption is generated in the mid-infrared band of 8-13μm in the second composite optical film layer 3, improving the absorption rate of the film layer and thus increasing the emissivity. In the visible light band, the interference cancellation effect reduces reflection loss and ensures high transmittance.

[0040] Compared to traditional metal-based films, the all-dielectric alternating stacked structure avoids the absorption of visible light by metal materials, significantly improving visible light transmittance. At the same time, it does not have the performance degradation problem caused by metal layer oxidation and aging, and the film layer has stronger chemical stability. Compared to a single film layer, the multi-layer alternating stacked structure can broaden the spectral modulation range, achieve precise matching between near-infrared reflection and mid-infrared emission, meet the core requirements of LED thermal radiation management, and the film layer has strong overall adhesion and is not prone to peeling.

[0041] In some embodiments, the total physical thickness of the composite optical film 2 is 1-5µm, preferably 2-3µm, specifically 1µm, 2µm, 3µm, 4µm, or 5µm; and it is composed of 10 to 30 alternately stacked low-refractive-index material layers and multiple high-refractive-index material layers. The film thickness is uniform with no significant thickness deviation; the film consists of 10-30 alternately stacked low-refractive-index and high-refractive-index material layers, and the number of layers can be flexibly adjusted according to the near-infrared reflection bandwidth requirements. The low-refractive-index and high-refractive-index material layers are stacked alternately, and the stacking order from the substrate outward can be either starting with a low-refractive-index layer or a high-refractive-index layer. Too few layers result in insufficient reflection bandwidth and low reflectivity, while too many layers lead to excessive film thickness and stress accumulation. Controlling the total thickness to 1-5µm ensures sufficient interference optical path difference to achieve a near-infrared weighted average reflectivity of ≥70%, while avoiding excessive stress caused by an excessively thick film. With controllable total thickness and uniform stress distribution within the film layer, it is less prone to failure phenomena such as cracking, warping, and delamination, making it suitable for the high-temperature thermal cycling environment of high-power LED packaging. The 10-30 layer stacked structure can achieve broadband near-infrared reflection, effectively blocking the near-infrared thermal radiation generated by the LED chip, while the visible light transmittance loss is small and does not affect the LED light output efficiency. The film layer is thin and light, which does not increase the overall volume and weight of the composite optical glass, making it easy to integrate into the LED packaging structure.

[0042] In some embodiments, the total physical thickness of the composite optical film layer 3 is 1µm to 3µm, and it is composed of 10 to 20 alternately stacked low-refractive-index material layers and multiple high-refractive-index material layers.

[0043] In this embodiment, the total physical thickness of the second composite optical film layer 3 is 1-3 μm, preferably 1.5-2.5 μm, and can specifically be 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, etc. It is composed of 10-20 alternating layers of low-refractive-index material and high-refractive-index material, with the stacking order from the substrate outwards either starting with a low-refractive-index layer or a high-refractive-index layer, used to enhance the absorption efficiency in the mid-infrared band. The thickness of each single layer is precisely designed according to the mid-infrared emissivity requirements, and the thickness deviation is generally controlled within ±5 nm. The mid-infrared band (8-13μm) has a longer wavelength, allowing for efficient interference absorption without excessively thick film layers. A stack of 10-20 layers can meet the absorption requirements of the mid-infrared band while avoiding increased stress due to excessive layers. A total thickness of 1-3μm balances mid-infrared emission performance with film stress. By optimizing the thickness of each film layer, a high absorption band is formed in the 8-13μm band, achieving an emissivity of ≥80% based on Kirchhoff's laws. This enables efficient mid-infrared emission, quickly radiating the heat absorbed by the composite optical glass into the atmosphere, improving passive heat dissipation efficiency and helping to reduce the junction temperature of the LED chip. Thinner and fewer film layers further reduce overall stress and improve the bonding stability between the film and the substrate, making it less prone to aging and detachment in high-temperature and humid environments. Combined with the first composite optical film layer 2, it achieves a synergistic effect of "near-infrared blocking + mid-infrared heat dissipation," ensuring long-term stable operation of the LED device.

[0044] In some embodiments, the material of the low refractive index material layer is selected from one or more of MgF2, SiO2, YF3, and CaF2.

[0045] It should be noted that the low-refractive-index material layer in this embodiment is an inorganic transparent medium with good film-forming properties. It can form a dense and uniform film layer through vacuum deposition process. The film layer surface is smooth and has no obvious pores or defects. A single material can be selected, or multiple materials can be mixed or used to form a composite layer to adapt to different deposition processes and performance requirements. The refractive index of the material is in the range of 1.35-1.45 (measured at 550nm), forming a significant refractive index difference with the high-refractive-index material layer.

[0046] In some embodiments, the material of the high refractive index material layer is selected from one or more of TiO2, Nb2O5, ZrO2, and Ta2O5.

[0047] It should be noted that the high refractive index material layer in this embodiment is made of high refractive index transparent oxide, which has good density and high mechanical strength after film formation, and is tightly bonded to the low refractive index material layer without obvious interface defects. A single material can be selected, or multiple materials can be mixed or a composite layer can be formed. TiO2 and Nb2O5 are preferred for their superior film formation performance. The refractive index range of the material is 2.0-2.4 (measured at 550nm), which forms a significant refractive index gradient with the low refractive index material layer, enhancing the interference effect.

[0048] In some embodiments, the glass substrate 1 is soda-lime glass, alkaline aluminosilicate glass, alkaline borosilicate glass, or alkaline aluminosilicate glass.

[0049] It should be noted that the glass substrate in this embodiment is a flat, transparent sheet structure with a thickness of 0.5-10mm, preferably 2-6mm. The surface is precision polished with a roughness Ra≤1nm to ensure the uniformity and adhesion of the film layer. The substrate is free of defects such as bubbles and cracks, has high mechanical strength, and can withstand temperature and pressure changes during vacuum deposition, making it suitable for industrial production processes.

[0050] This embodiment also provides a method for preparing composite optical glass, including the following steps: S1. Provide glass substrate 1; S2. A first composite optical film layer 2 is deposited on the first side of the glass substrate 1 using a thermal evaporation process assisted by ion beam deposition. S3. A second composite optical film layer 3 is deposited on the second surface of the glass substrate 1 using a thermal evaporation process assisted by ion beam deposition.

[0051] It should be noted that in S1, the glass substrate needs to undergo cleaning, drying, and plasma pretreatment to remove surface oil, impurities, and oxide layers, thereby improving the surface activity of the substrate and enhancing the adhesion between the film and the substrate. S2 and S3 employ ion beam-assisted deposition thermal evaporation processes, which heat the film material to an evaporation state through thermal evaporation, forming gaseous atoms or molecules. Simultaneously, ion beams bombard the substrate surface and the deposited film, allowing gaseous particles to adhere more uniformly to the substrate surface and improving the film density. The two-step deposition process precisely controls the deposition parameters to meet the performance requirements of the first and second composite optical films, ensuring that the film performance meets the standards.

[0052] In some embodiments, the thermal evaporation process of ion beam-assisted deposition is carried out at a vacuum level not exceeding 2.0 × 10⁻⁶. -3 It takes place in the chamber of Pa.

[0053] In this embodiment, the high vacuum environment reduces the content of residual gases (such as oxygen, water vapor, and dust) within the chamber, preventing these gases from reacting with the evaporated film material, which could lead to film oxidation and impurity doping, thus affecting the film's optical performance. Simultaneously, the high vacuum environment reduces collisions between gaseous film particles, allowing them to deposit more uniformly and stably on the glass substrate surface, improving film thickness uniformity and density. The vacuum level is controlled at 2.0 × 10⁻⁶. -3 Below Pa, the interference of residual gas on the ion beam assist effect can be effectively avoided, ensuring the adhesion between the film and the substrate.

[0054] In some embodiments, when depositing the first composite optical film 2 or the second composite optical film 3, the deposition rate is controlled between 0.5 nm / s and 1.5 nm / s.

[0055] In this embodiment, if the deposition rate is too high, the gaseous film particles will not have enough time to uniformly adhere to the substrate surface, which will easily lead to a loose and porous film with a large refractive index deviation. Furthermore, the film will not be tightly bonded to the substrate and will easily detach. If the deposition rate is too low, the film will grow slowly, resulting in low production efficiency. It will also easily lead to segregation and crystallization defects in the film, increasing light absorption loss. Controlling the deposition rate between 0.5-1.5 nm / s can balance the film quality and production efficiency, ensuring that the film is dense, uniform, and meets the optical performance standards.

[0056] It should be noted that the thickness of each layer in the first composite optical film layer 2 and the second composite optical film layer 3 in this embodiment is designed by an optimization algorithm. The optimization algorithm is selected from at least one of particle swarm optimization, genetic algorithm, and simulated annealing algorithm. The optimization objective is to make the composite optical glass satisfy the following: the weighted average solar reflectivity in the 0.8μm to 2.5μm band is greater than 70%, and the emissivity in the 8-13μm band is greater than or equal to 80%.

[0057] This embodiment also provides an optical device comprising the aforementioned composite optical glass.

[0058] This embodiment utilizes the high visible light transmittance of composite optical glass to ensure the light transmission and emission performance of optical devices; it utilizes the high reflectivity of the 0.8-2.5μm band to block near-infrared thermal radiation and reduce heat accumulation; and it utilizes the high emissivity of the 8-13μm band to achieve passive radiation heat dissipation and reduce the operating temperature of the device; through the integrated function of composite optical glass, it replaces the complex structure of the traditional "light-transmitting component + heat dissipation component + heat insulation component", simplifying device design.

[0059] In one embodiment, the optical device is an LED package heat dissipation assembly.

[0060] In this embodiment, the composite optical glass serves as the light-emitting window and heat dissipation interface of the LED packaging heat dissipation component. Its first composite optical film layer 2 faces the LED chip, and its second composite optical film layer 3 faces the external environment. The composite optical glass is fixedly connected to the LED substrate and chip via encapsulating adhesive, forming a sealed packaging structure that serves both light transmission and heat dissipation functions, eliminating the need for additional heat sinks or cooling fans. It can significantly reduce the junction temperature of the LED chip without affecting the LED's light emission efficiency, thereby improving luminous efficiency and reducing problems such as color temperature drift and luminous efficacy decay. It avoids the drawbacks of traditional active heat dissipation components, such as large size, high cost, and low reliability, simplifying the LED packaging structure, reducing packaging volume, and adapting to the needs of miniaturized, high-density LED packaging. The composite optical film layer has strong stability and is not prone to aging or detachment under the high-temperature thermal cycling environment of LED packaging, extending the lifespan of the LED device. The heat dissipation effect is stable and energy-free, reducing the operating and maintenance costs of LED devices, making it particularly suitable for high-power LED packaging scenarios.

[0061] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0062] The specific embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention. For example, to clearly show the structure of the optical film on the glass surface, the accompanying drawings may schematically enlarge the film thickness.

[0063] Example 1 MgF2 / Ta2O5 double-sided high-transparency composite heat-insulating glass: The composite heat-insulating glass described in this embodiment has a first composite optical film layer 2 and a second composite optical film layer 3 respectively disposed on the two main surfaces of the substrate.

[0064] This embodiment uses soda-lime glass as the substrate, with dimensions of 50mm × 50mm × 2mm. Both main surfaces are finely polished, with a surface roughness Ra < 1nm. Before use, the substrate undergoes rigorous cleaning: first, ultrasonic cleaning in acetone for 15 minutes to remove oil and organic residues; then, ultrasonic cleaning in anhydrous ethanol for 15 minutes; finally, rinsing with deionized water and ultrasonic cleaning for 10 minutes. After cleaning, it is dried with high-purity nitrogen and immediately placed in a vacuum chamber to avoid secondary contamination.

[0065] In this embodiment, the first composite optical film layer 2 is composed of alternating stacks of low-refractive-index material MgF2 (refractive index approximately 1.38 @ 550 nm) and high-refractive-index material Ta2O5 (refractive index approximately 2.1 @ 550 nm). This was achieved through optimization, with the goal of achieving high transmittance in the visible light band (380-780 nm) and high reflectance in the near-infrared band (780–2500 nm). Its structure is as follows... Figure 1 As shown: From the substrate outwards, it includes the following 14 layers (total thickness approximately 1482.20 nm): First layer: Ta2O5, 28.5nm; Second layer: MgF2, 112.3nm; Third layer: Ta2O5, 95.6nm; Fourth layer: MgF2, 85.7nm; Fifth layer: Ta2O5, 70.2nm; Sixth layer: MgF2, 120.8nm; Seventh layer: Ta2O5, 38.9nm; Eighth layer: MgF2, 95.4nm; Ninth layer: Ta2O5, 223.1nm; Tenth layer: MgF2, 95.4nm; Eleventh layer: Ta2O5, 195.1nm; Twelfth layer: MgF2, 95.4nm; Thirteenth layer: Ta2O5, 100.1nm; Fourteenth layer: MgF2, 125.7nm.

[0066] The first composite optical film layer in this embodiment has 14 layers and a total thickness of 1.48 μm, which falls within the range of 1-5 μm total thickness and composed of 10-30 layers.

[0067] The preparation was carried out using an electron beam evaporation deposition system (equipped with an ion beam assisted deposition system), and the specific steps are as follows: Vacuuming: Place the cleaned substrate into the vacuum chamber, close the chamber door, and start the vacuum system. First, use a mechanical pump to evacuate to a low vacuum, then use a molecular pump to evacuate to a high vacuum, until the background vacuum level reaches ≤2.0×10⁻⁶. -3 Pa.

[0068] Ion beam cleaning: Before deposition, turn on the ion source, using argon as the working gas at a pressure of 1.5 × 10⁻⁶. -2 At Pa, beam voltage 300V, beam current 50mA, the substrate surface is subjected to ion beam cleaning for 5 minutes to further remove surface adsorbates and activate the surface, thereby enhancing the adhesion of the film layer.

[0069] Film deposition: Each layer was deposited sequentially according to the above order. During the deposition process, a quartz crystal film thickness monitor was used to monitor the film thickness in real time, with a control accuracy of ±0.1 nm. The deposition parameters for each layer are as follows: MgF2 layer: MgF2 particles (99.99% purity) were evaporated by electron beam at a deposition rate of 1.0 nm / s, and ion source-assisted deposition was used (argon flow rate 8 sccm, beam voltage 150 V, beam current 20 mA) to ensure a dense film.

[0070] Ta2O5 layer: Ta2O5 particles (99.99% purity) were evaporated by electron beam at a deposition rate of 0.5 nm / s. At the same time, ion source-assisted deposition was turned on (oxygen flow rate 10 sccm, beam voltage 200 V, beam current 30 mA) to compensate for oxygen vacancies and obtain a dense film with accurate stoichiometry.

[0071] After each layer is deposited, pause for 10 seconds and wait for the film thickness monitor to stabilize before depositing the next layer to avoid interlayer mixing.

[0072] Annealing: After deposition, the sample was allowed to cool naturally to room temperature in a vacuum chamber, then removed and placed in an annealing furnace at 250°C for 1.5 hours (air atmosphere) to eliminate internal stress and further optimize the film structure. After annealing, the sample was allowed to cool naturally to room temperature.

[0073] Second composite optical film layer 3: To optimize the overall effect, the following 20-layer structure is adopted (total thickness approximately 2432.6 nm): 1. First layer: Ta2O5, 25.6nm; 2. Second layer: MgF2, 178.3nm; 3. Third layer: Ta2O5, 197.6nm; 4. Fourth layer: MgF2, 185nm; 5. Fifth layer: Ta2O5, 70.0nm; 6. Sixth layer: MgF2, 155.8nm; 7. Seventh layer: Ta2O5, 138nm; 8. Eighth layer: MgF2, 95.4nm; 9. Ninth layer: Ta2O5, 103.1 nm; 10. Tenth layer: MgF2, 97.5nm; 11. Eleventh layer: Ta2O5, 135.1nm; 12. Twelfth layer: MgF2, 96.4nm; 13. Thirteenth layer: Ta2O5, 150.8nm; 14. Fourteenth layer: MgF2, 153.6nm; 15. Fifteenth layer: Ta2O5, 99.5nm; 16. Sixteenth layer: MgF2, 67.7nm; 17. The seventeenth layer: Ta2O5, 19.1 nm; 18. Eighteenth layer: MgF2, 205.4nm; 19. Nineteenth layer: Ta2O5, 75.7nm; 20. Twentieth layer: MgF2, 183nm.

[0074] The first film system has 14 layers (1.48 μm), which meets the requirements of (1-5 μm, 10-30 layers), and the second film system has 20 layers (2.43 μm), which meets the requirements of (1-3 μm, 10-20 layers). The total thickness of both sides is approximately 3.91 μm, which is less than 5 μm, effectively controlling the film stress.

[0075] The preparation method is the same as above, using electron beam evaporation deposition equipment (ion beam assisted deposition), and the process parameters are consistent. Specific steps: The cleaned substrate was placed into a vacuum chamber and evacuated to a vacuum level of ≤2.0×10⁻⁶. -3 Pa.

[0076] The 14-layer film system of Example 1 was sequentially deposited on the upper surface of the substrate (first main surface) with the same deposition parameters as in Example 1.

[0077] After deposition, the substrate is flipped over inside the vacuum chamber so that the lower surface faces upward.

[0078] The 20-layer film system designed in this embodiment was sequentially deposited on the lower surface, with the same deposition parameters as in Example 1 (Ta2O5 0.5 nm / s, MgF2 1.0 nm / s, and the same ion source auxiliary parameters).

[0079] (5) After deposition, the sample was annealed at 250°C for 1.5 hours (in air).

[0080] like Figure 2 As shown, the double-sided coated glass has an average transmittance of 90.8% in the visible light band of 380-780 nm and a weighted average solar reflectance of 75.7% in the near-infrared band of 780-2500 nm. Tests showed that its average emissivity in the 8-13 μm band was 84%. The first film system has a total thickness of approximately 1.48 μm (14 layers), and the second film system has a total thickness of approximately 2.43 μm (20 layers), for a total double-sided thickness of approximately 3.91 μm, effectively controlling film stress.

[0081] Example 2 SiO2 / TiO2 double-sided high-transparency composite heat-insulating glass: The substrate is the same as in Example 1: soda-lime glass (50 mm × 50 mm × 2 mm, R...). a <1 nm), the cleaning process is the same as in Example 1.

[0082] The composite heat-insulating glass has a first composite optical film layer 2 and a second composite optical film layer 3 respectively disposed on the two main surfaces of the substrate.

[0083] Substrate: Same as in Example 1.

[0084] like Figure 3 The upper surface film system consists of the following 12 layers (total thickness approximately 1597.60 nm) from the substrate outwards.

[0085] 1. First layer: SiO2, 55.6nm; 2. Second layer: TiO2, 258.3nm; 3. Third layer: SiO2, 97.4nm; 4. Fourth layer: TiO2, 235nm; 5. Fifth layer: SiO2, 170.0nm; 6. Sixth layer: TiO2, 355.8nm; 7. Seventh layer: SiO2, 128nm; 8. Eighth layer: TiO2, 164.4nm; 9. Ninth layer: SiO2, 252.1nm; 10. Tenth layer: TiO2, 33.5nm; 11. Eleventh layer: SiO2, 75.1nm; 12. Twelfth layer: TiO2, 72.4nm.

[0086] Lower surface film system: To optimize the overall effect, the following 12-layer structure (total thickness approximately 1897.6 nm) is adopted: 1. First layer: SiO2, 111nm; 2. Second layer: TiO2, 253.3nm; 3. Third layer: SiO2, 99.5nm; 4. Fourth layer: TiO2, 75.1nm; 5. Fifth layer: SiO2, 50nm; 6. Sixth layer: TiO2, 43.8nm; 7. Seventh layer: SiO2, 250nm; 8. Eighth layer: TiO2, 304nm; 9. Ninth layer: SiO2, 75nm; 10. Tenth layer: TiO2, 99nm; 11. Eleventh layer: SiO2, 54nm; 12. Twelfth layer: TiO2, 43nm.

[0087] The preparation method includes the following steps: The material was prepared using reactive magnetron sputtering with a JGP-450 magnetron sputtering system. The specific steps are as follows: The cleaned substrate was placed in a vacuum chamber and evacuated until the background vacuum level was ≤2.0×10⁻⁶. -3 Pa.

[0088] An argon-oxygen mixed atmosphere (Ar:O2 = 4:1, total flow rate 20 sccm) is introduced, and the working pressure is 0.5 Pa.

[0089] Top surface deposition: Silicon (99.99% purity) and titanium (99.99% purity) targets were used for alternating deposition in a mid-frequency AC magnetron sputtering mode. SiO2 layer: silicon target power 200 W, deposition rate 0.3 nm / s; TiO2 layer: titanium target power 250 W, deposition rate 0.25 nm / s. Film thickness was monitored using a quartz crystal, and 12 layers were deposited sequentially according to the designed thickness.

[0090] Flip the substrate and deposit 12 layers on the lower surface using the same process.

[0091] After deposition, the sample was annealed at 300°C for 1 hour (in air atmosphere) to crystallize TiO2 and relieve stress.

[0092] like Figure 4 As shown, the double-sided coated glass has an average transmittance of 92.1% in the visible light band of 380-780 nm and a weighted average solar reflectance of 77.3% in the near-infrared band of 780-2500 nm. Tests showed that its average emissivity in the 8-13 μm band was 86%. The total thickness of the first film system is approximately 1.90 μm (12 layers), the total thickness of the second film system is approximately 1.46 μm (12 layers), and the total thickness of both sides is approximately 3.36 μm.

[0093] Example 3 Examples of applications of composite optical glass in LED packaging heat dissipation components: The composite optical glass prepared in Example 2 was used as the surface protective cover plate of the LED packaging structure. Specifically, it was cut into a 10 mm × 10 mm × 1 mm square cover plate and bonded to the surface of the LED lamp board using thermally conductive adhesive. Under outdoor sunny weather conditions (ambient temperature 31℃, illuminance 800 W / m²), 2 (Relative humidity 50%), use an infrared thermal imager to record the operating temperature of the lamp panel. Figure 5 As shown in the test results, the center operating temperature of the blank LED light board without any cover plate is 89℃. After using the composite optical glass of this embodiment as a cover plate, the operating temperature of the LED light board is significantly reduced to 70℃, a temperature reduction of 19℃. Simultaneously, a spectrometer test showed that the average transmittance of the cover plate in the 380-780 nm visible light band is 92.1%, indicating that the composite optical glass significantly suppresses the accumulation of near-infrared heat radiation while ensuring efficient visible light transmission. This embodiment demonstrates that the composite optical glass is suitable for LED packaging heat dissipation scenarios, effectively reducing junction temperature, improving luminous efficiency, and extending service life.

[0094] Example 4 The difference from Example 2 is that this example uses a MgF2 / Ta2O5 material system instead of SiO2 / TiO2. Using the same substrate and double-sided deposition process as Example 2, 14 layers of MgF2 / Ta2O5 film (total thickness approximately 1.48 μm) were deposited on the upper surface, and 20 layers of MgF2 / Ta2O5 film (total thickness approximately 2.43 μm) were deposited on the lower surface, for a total thickness of approximately 3.91 μm. The sample was evaluated under the same testing conditions as in Example 2. The results showed that its average visible light transmittance reached 92.1%, near-infrared reflectance was 77.3%, and mid-infrared emissivity was 86%. This comparison indicates that although the MgF2 / Ta2O5 combination already achieves excellent spectral selectivity, the SiO2 / TiO2 combination has higher refractive index contrast in certain wavelength bands. Further optimization of the film system design can achieve higher visible light transmittance and near-infrared reflectance at a thinner thickness, while also achieving higher mid-infrared emissivity.

[0095] Comparative Example 1 Comparative Example 1 is ordinary soda-lime glass, using the exact same substrate as Example 1 (50 mm × 50 mm × 2 mm, surface roughness Ra < 1 nm), but without any coating treatment. Characterization was performed under the same test conditions as Example 1. The results showed that the average visible light transmittance was 91.5%, slightly lower than 93.2% in Example 1; the near-infrared weighted average reflectance was only 7.2%, far lower than 70.0% in Example 1; and the mid-infrared average emissivity was 84%, comparable to 82% in Example 1. This comparison shows that ordinary glass has almost no reflectivity for near-infrared radiation; near-infrared energy from sunlight will directly pass through or be absorbed, leading to heat accumulation. In contrast, this invention, by depositing a multilayer optical film structure, increases the near-infrared reflectance by nearly 10 times while maintaining high visible light transmittance, demonstrating the excellent spectral selectivity of the optical film structure of this invention.

[0096] Comparative Example 2 MgF2 / Ta2O5 single-sided high-transparency composite heat-insulating glass: This embodiment uses soda-lime glass as the substrate, with dimensions of 50mm × 50mm × 2mm. Both main surfaces are finely polished, with a surface roughness Ra < 1nm. Before use, the substrate undergoes rigorous cleaning: first, ultrasonic cleaning in acetone for 15 minutes to remove oil and organic residues; then, ultrasonic cleaning in anhydrous ethanol for 15 minutes; finally, rinsing with deionized water and ultrasonic cleaning for 10 minutes. After cleaning, it is dried with high-purity nitrogen and immediately placed in a vacuum chamber to avoid secondary contamination.

[0097] In this embodiment, the optical film structure is deposited only on one main surface (the first main surface) of the glass substrate, namely the first composite optical film layer 2, which is a single-sided coating structure. This film system is composed of alternating stacks of low-refractive-index material MgF2 (refractive index approximately 1.38@550nm) and high-refractive-index material Ta2O5 (refractive index approximately 2.1@550nm), optimized to achieve high transmittance in the visible light band (380-780nm) and high reflectance in the near-infrared band (780–2500nm). Its structure is as follows: Figure 6 As shown: From the substrate outwards, it includes the following 14 layers (total thickness approximately 1482.20 nm): First layer: Ta2O5, 28.5nm; Second layer: MgF2, 112.3nm; Third layer: Ta2O5, 95.6nm; Fourth layer: MgF2, 85.7nm; Fifth layer: Ta2O5, 70.2nm; Sixth layer: MgF2, 120.8nm; Seventh layer: Ta2O5, 38.9nm; Eighth layer: MgF2, 95.4nm; Ninth layer: Ta2O5, 223.1nm; Tenth layer: MgF2, 95.4nm; Eleventh layer: Ta2O5, 195.1nm; Twelfth layer: MgF2, 95.4nm; Thirteenth layer: Ta2O5, 100.1nm; Fourteenth layer: MgF2, 125.7nm.

[0098] The first composite optical film layer in this embodiment has 14 layers and a total thickness of 1.48 μm, which falls within the range of 1-5 μm total thickness and composed of 10-30 layers.

[0099] The preparation was carried out using an electron beam evaporation deposition system (equipped with an ion beam assisted deposition system), and the specific steps are as follows: Vacuuming: Place the cleaned substrate into the vacuum chamber, close the chamber door, and start the vacuum system. First, use a mechanical pump to evacuate to a low vacuum, then use a molecular pump to evacuate to a high vacuum, until the background vacuum level reaches ≤2.0×10⁻⁶. -3 Pa.

[0100] Ion beam cleaning: Before deposition, turn on the ion source, using argon as the working gas at a pressure of 1.5 × 10⁻⁶. -2 At Pa, beam voltage 300V, beam current 50mA, the substrate surface is subjected to ion beam cleaning for 5 minutes to further remove surface adsorbates and activate the surface, thereby enhancing the adhesion of the film layer.

[0101] Film deposition: Each layer was deposited sequentially according to the above order. During the deposition process, a quartz crystal film thickness monitor was used to monitor the film thickness in real time, with a control accuracy of ±0.1 nm. The deposition parameters for each layer are as follows: MgF2 layer: MgF2 particles (99.99% purity) were evaporated by electron beam at a deposition rate of 1.0 nm / s, and ion source-assisted deposition was used (argon flow rate 8 sccm, beam voltage 150 V, beam current 20 mA) to ensure a dense film.

[0102] Ta2O5 layer: Ta2O5 particles (99.99% purity) were evaporated by electron beam at a deposition rate of 0.5 nm / s. At the same time, ion source-assisted deposition was turned on (oxygen flow rate 10 sccm, beam voltage 200 V, beam current 30 mA) to compensate for oxygen vacancies and obtain a dense film with accurate stoichiometry.

[0103] After each layer is deposited, pause for 10 seconds and wait for the film thickness monitor to stabilize before depositing the next layer to avoid interlayer mixing.

[0104] Annealing: After deposition, the sample was allowed to cool naturally to room temperature in a vacuum chamber, then removed and placed in an annealing furnace at 250°C for 1.5 hours (air atmosphere) to eliminate internal stress and further optimize the film structure. After annealing, the sample was allowed to cool naturally to room temperature.

[0105] The transmittance and reflectance of the samples obtained in this embodiment were measured using a spectrophotometer (PerkinElmer Lambda 950). The test wavelength range was 300-2500 nm, with a step size of 1 nm, and the incident angle was 0° (perpendicular incidence). The test results are as follows: Figure 2 As shown, this single-sided coated glass has an average transmittance of 93.2% in the visible light band of 380–780 nm and a weighted average solar reflectance of 70% in the near-infrared band of 780–2500 nm. Its average emissivity in the 8–13 μm band was also tested to be 82%.

[0106] The difference between this comparative example and Example 1 is that only one main surface of the glass substrate is coated, while the other surface is left uncoated. Using the same substrate and preparation process as Example 1, a 14-layer MgF2 / Ta2O5 film system (total thickness approximately 1.48 μm) was deposited on the upper surface of the substrate, identical to that in Example 1, while no film was deposited on the lower surface. Characterization was performed according to the same test methods as in Example 2, and the results are as follows: Figure 7 As shown, the average visible light transmittance is 93.2%, the near-infrared weighted average reflectance is 70.0%, and the mid-infrared average emissivity is 82%. In Example 2, with a double-sided deposition system (14 layers on the upper surface and 20 layers on the lower surface, with a total thickness of approximately 3.91 μm), the visible light transmittance remains at a high level of 90.8%, the near-infrared reflectance is increased to 75.7%, and the mid-infrared emissivity reaches 84%. Compared to single-sided coating, the double-sided coating structure increases the near-infrared reflectance by 5.7 percentage points, demonstrating that the double-sided coating design can more effectively reflect near-infrared heat without significantly sacrificing visible light transmittance, exhibiting a synergistic enhancement effect.

[0107] Comparative Example 3 The difference between this comparative example and Example 3 is that uncoated ordinary soda-lime glass is used as the LED encapsulation cover plate, while its dimensions, thickness, and testing conditions are the same as in Example 3. Specifically, under outdoor sunny weather conditions (ambient temperature 31℃, light intensity 800W / m²), 2 (Relative humidity 50%), uncoated ordinary soda-lime glass was cut into 10mm × 10mm × 1mm square cover plates, which were then bonded to the surface of an LED light panel of the same specifications using thermally conductive adhesive. The same testing method as in Example 3 was used. The operating temperature of the LED light panel was recorded using an infrared thermal imager. Figure 5 As shown, the center operating temperature of the LED light panel using a common soda-lime glass cover is 89℃.

[0108] The comparison shows that although ordinary soda-lime glass can maintain a high visible light transmittance, it lacks effective reflection capability in the near-infrared band (especially the thermal radiation band generated by LED chips), and therefore cannot suppress the accumulation of heat on the surface of the lamp board, resulting in a weak heat dissipation effect. In contrast, the composite optical glass of Embodiment 3 of this invention, through a double-sided coating design, maintains high light transmittance while significantly reflecting near-infrared thermal radiation, reducing the operating temperature of the LED lamp board to 70°C, a temperature reduction of 19°C. This demonstrates its excellent thermal management performance as a heat dissipation component for LED packaging.

[0109] It should be noted that the weighted average solar reflectance in the above embodiments is calculated using the following formula: Where, ρ(λ): sample reflectance (0~1); S(λ): ASTM G173-03 AM1.5 standard solar spectrum; Integration range: 800nm ​​to 2500nm.

[0110] In summary, this embodiment provides a composite optical glass, its preparation method, and its application. This embodiment achieves an average transmittance greater than 90% for visible light with wavelengths from 0.38 μm to 0.78 μm, a weighted average solar reflectance greater than 70% in the 0.8 μm to 2.5 μm band, and an emissivity greater than or equal to 80% in the 8-13 μm band by using a first and a second composite optical film layer on both sides of the main surface of the glass substrate. The composite optical glass of this invention maintains extremely high visible light transmittance while efficiently reflecting near-infrared heat and simultaneously achieving high emissivity in the mid-infrared band.

[0111] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, any technical solutions obtained by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concept of the present invention and on the existing technology should be within the scope of protection defined by the claims.

Claims

1. A composite optical glass, characterized in that, It includes a glass substrate (1) and a first composite optical film layer (2) and a second composite optical film layer (3) respectively disposed on the main surfaces on both sides of the glass substrate (1). The composite optical glass has an average transmittance of more than 90% for visible light with wavelengths from 0.38μm to 0.78μm, a weighted average solar reflectance of more than 70% in the 0.8μm to 2.5μm band, and an emissivity of more than or equal to 80% in the 8-13μm band.

2. The composite optical glass according to claim 1, characterized in that, The first composite optical film layer (2) is composed of multiple low-refractive-index material layers and multiple high-refractive-index material layers stacked alternately from the inside to the outside; The second composite optical film layer (3) is composed of multiple low-refractive-index material layers and multiple high-refractive-index material layers stacked alternately from the inside out; or, The first composite optical film layer (2) is composed of multiple low-refractive-index material layers stacked alternately from the inside to the outside; The second composite optical film layer (3) is formed by alternating stacking of multiple high refractive index material layers and multiple low refractive index material layers from the inside out.

3. The composite optical glass according to claim 2, characterized in that, The first composite optical film layer (2) has a total physical thickness of 1-5µm and is composed of 10 to 30 alternately stacked low refractive index material layers and multiple high refractive index material layers.

4. The composite optical glass according to claim 2, characterized in that, The total physical thickness of the second composite optical film layer (3) is 1µm to 3µm, and it is composed of 10 to 20 alternately stacked low refractive index material layers and multiple high refractive index material layers.

5. A composite optical glass according to any one of claims 2-4, characterized in that, The material of the low refractive index material layer is selected from one or more of MgF2, SiO2, YF3, and CaF2.

6. A composite optical glass according to any one of claims 2-4, characterized in that, The material of the high refractive index material layer is selected from one or more of TiO2, Nb2O5, ZrO2, and Ta2O5.

7. The composite optical glass according to claim 1, characterized in that, The glass substrate (1) is made of soda-lime glass, alkaline aluminosilicate glass, alkaline borosilicate glass or alkaline aluminosilicate glass.

8. A method for preparing a composite optical glass as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Provide a glass substrate (1); S2. A first composite optical film (2) is deposited on the first side of the glass substrate (1) using a thermal evaporation process assisted by ion beam deposition. S3. A second composite optical film (3) is deposited on the second surface of the glass substrate (1) using a thermal evaporation process assisted by ion beam deposition.

9. The preparation method according to claim 8, characterized in that, The ion beam assisted deposition process is carried out at a vacuum degree not higher than 2.0*10 -3 The deposition rate is controlled between 0.5 nm / s and 1.5 nm / s when depositing the low refractive index material layer or the high refractive index material layer.

10. An optical device, characterized in that, It includes any one of the composite optical glasses of claims 1-7.

Images