Infrared-barrier low-sheet-resistance AZO coated glass and preparation method thereof

Abstract

The invention discloses infrared-barrier low-sheet-resistance AZO coated glass and a preparation method thereof. Aiming at the defects of low yield, high tempering energy consumption, large FTO film haze, high sheet resistance and the like in the traditional double-sided coating, a multilayer alternately deposited dielectric layer and AZO composite functional layer laminated structure is constructed on a single side of glass, and a surface oxygen barrier layer and an antireflection layer are combined, wherein the dielectric layer adopts materials (10-20nm) such as silicon oxide / silicon nitride and the like to realize Na ion isolation and antireflection; each AZO functional layer comprises a Zn layer with the thickness of 5-30 nm and an AZO layer with the thickness of 300-500 nm, and the sheet resistance is reduced by accurately controlling sputtering parameters (the vacuum degree is 2.0-6.0 * 10 <-3 > Pa, and the specific gas proportion); and a silicon nitride / zirconium oxide oxygen barrier layer (30-100nm) and a silicon oxide / magnesium fluoride anti-reflection layer (50-150nm) are covered on the surface layer. According to the preparation process, single-face multi-lamination magnetron sputtering and convection tempering are combined, so that the surface resistance is reduced to 5 ohms and is reduced by 28.6% compared with that of an original patent, the average infrared transmittance of 780-2500nm is reduced to 15.0%, the yield is increased by 30% or more, the bottlenecks of mechanical damage and high energy consumption of traditional double-face coating are broken through, and remarkable advantages are formed in the aspects of infrared barrier efficiency and mass production economy.

Description

Technical Field

[0001] The present invention relates to the field of AZO coated glass, and particularly to an infrared-blocking AZO coated glass with low sheet resistance and a preparation method thereof. Background Art

[0002] Transparent conductive oxide (TCO) films have been widely used in fields such as household appliances (such as ovens, freezers, wine cabinets) and building curtain wall glasses due to their high light transmittance, conductivity, and good infrared-blocking function, for improving application energy efficiency. Currently, the mainstream TCO films in the market include indium tin oxide (ITO) and fluorine-doped tin oxide (FTO). ITO films are usually deposited by magnetron sputtering, and have the best conductive performance, infrared-blocking performance, and visible light transmittance. However, indium is a rare metal, with limited reserves on the earth, certain toxicity, and high price, making it difficult to achieve large-area and low-cost applications. In addition, ITO films are prone to grain growth during high-temperature treatment, resulting in a decrease in film layer stability. FTO films are usually prepared by an online deposition thermal spraying method, that is, a solution containing tin tetrachloride and fluoride is sprayed on the glass air surface at the outlet end of the tin bath, and chemical decomposition, oxidation, and deposition are carried out using the temperature (about 400 °C) during the glass production process itself. Although this deposition method has a relatively low preparation cost, it has the following deficiencies: poor production flexibility: relying on the float line kiln for production, it is difficult to achieve rapid switching of glasses with different thicknesses; large haze: lower sheet resistance FTO films often exhibit a pyramidal surface structure, resulting in increased optical scattering and a relatively large haze, unable to meet the application requirements of high optical clarity; poor film uniformity: the conductive performance is limited by the thickness, and the sheet resistance is difficult to reduce to below 10 Ω, resulting in a low infrared radiation blocking rate.

[0003] In recent years, trivalent metal element-doped zinc oxide materials, especially aluminum-doped zinc oxide (AZO), have gradually become the best choice to replace ITO and FTO due to their excellent optical properties, wide raw material sources, low price, and non-toxicity. AZO films can be deposited with high quality by magnetron sputtering, showing good application prospects. To meet the application requirements of more efficient infrared blocking, it is necessary to further reduce the sheet resistance of the AZO thin film to below 10 ohms, while ensuring that the thin film has both high visible light transmittance and infrared blocking properties. Chinese Invention Patent 2024107646117 discloses a preparation method of infrared blocking AZO coated glass, which includes a Na ion blocking layer (10 - 20 nm), a Zn layer (5 - 30 nm), an AZO layer (300 - 500 nm), an oxygen blocking layer (30 - 50 nm), and an antireflection layer (40 - 150 nm) sequentially obtained by magnetron sputtering on the tin side and the non-tin side of the glass substrate respectively, and then undergoes forced convection high-temperature toughening treatment in a toughening furnace. Finally, an infrared blocking AZO coated glass with a comprehensive surface resistance not higher than 10 ohms, an average transmittance in the infrared band of 780 - 2500 nm not greater than 17%, and an average transmittance in the visible light band of 380 - 780 nm not lower than 79.0% is obtained. However, this patent still has the following disadvantages: (1) The product yield is low, which increases the manufacturing cost. In this production process, the film is first coated on one side of the glass, and then the glass is flipped to coat the other side. Therefore, more tooling needs to be added to the coating production line to meet the requirement of glass flipping. In addition, during the process of coating the second side, the surface cleaning brush and the driving roller are in intense physical contact with the first coated film surface, which may lead to the risk of mechanical damage to the coated film surface and reduce the product yield; (2) More complex toughening equipment is required to meet the demand for high-quality toughening, which indirectly increases the manufacturing cost of the product. Traditional toughening furnaces usually rely on infrared radiation to heat the glass. However, this heating method cannot quickly and evenly heat the double-sided coated glass because the coated film surface has a certain heat reflection ability, and the glass cannot be heated quickly, resulting in reduced thermal efficiency and increased energy consumption during the toughening process. Summary of the Invention

[0004] In view of the above defects of the prior art, the present invention provides an infrared blocking low sheet resistance AZO coated glass, which includes: a glass substrate; n laminated structures sequentially deposited on one side of the glass substrate, where n ≥ 2; each laminated structure includes a dielectric layer and an AZO composite functional layer; and a composite covering layer covering the surface of the outermost laminated structure; wherein, the AZO composite functional layer includes a Zn layer and an AZO layer, and the thickness of each AZO layer thin film does not exceed 500 nm, and the composite covering layer includes an oxygen blocking layer and an antireflection layer.

[0005] Further, the dielectric layer material is selected from one of silicon oxide, silicon nitride, titanium oxide, and zirconium oxide, with a thickness of 10 - 20 nm; the film thickness of the Zn layer is 5 - 30 nm; the oxygen barrier layer is selected from one of silicon oxide, silicon nitride, zirconium oxide, titanium oxide, and zinc oxide tin, with a thickness of 30 - 100 nm; the antireflection layer material is silicon oxide or magnesium fluoride, with a thickness of 50 - 150 nm.

[0006] The present invention also provides a method for preparing the coated glass as described above, including: (a) Cleaning the glass substrate; (b) Alternately depositing at least two groups of dielectric layer / AZO composite functional layer stacks on one side of the glass; (c) Sequentially depositing an oxygen barrier layer and an antireflection layer on the surface of the stack; wherein both the dielectric layer and the AZO composite functional layer are deposited step by step by magnetron sputtering process.

[0007] Further, the deposition conditions of the dielectric layer are: the background vacuum is 2.0 - 6.0×10 -3 Pa, the substrate temperature is 40 - 80 °C, the sputtering power density is 6 - 10 W / cm 2 , and the sputtering gas is a mixture of oxygen and argon with a mixing ratio of 1:2 - 1:3; the sputtering method is one of DC, medium frequency, and radio frequency.

[0008] Further, the sputtering method of the magnetron sputtering Zn layer is one of DC, medium frequency, and radio frequency, and the sputtering conditions are: the background vacuum is 2.0 - 6.0×10 -3 Pa, the substrate temperature is 40 - 80 °C, the sputtering power density is 10 - 30 W / cm 2 , and the sputtering gas is argon.

[0009] Further, the sputtering method of the magnetron sputtering AZO layer is one of DC, medium frequency, and radio frequency, and the sputtering conditions are: the background vacuum is 2.0 - 6.0×10 -3 Pa, the substrate temperature is 50 - 100 °C, the sputtering power density is 10 - 30 W / cm 2 , and the sputtering gas is a mixture of oxygen and argon with a mixing ratio of 1:8 - 1:10.

[0010] Further, the sputtering conditions of the oxygen barrier layer are: the background vacuum is 2.0 - 6.0×10 -3 Pa, the substrate temperature is 40 - 80 °C, the sputtering power density is 10 - 22 W / cm 2 , and the sputtering gas is a mixture of nitrogen and argon with a mixing ratio of 3:1 - 3:2.

[0011] Further, the sputtering conditions of the antireflection layer are: the background vacuum is 2.0 - 6.0×10-3 Pa, the substrate temperature is 40 - 80 °C, and the sputtering power density is 8 - 15 W / cm 2 , and the sputtering gas is a mixture of oxygen and argon with a mixing ratio of 1:2 - 1:3.

[0012] Through the alternate laminated design of the single-sided multi-layer AZO composite functional layer and the dielectric layer, combined with the composite covering structure of the oxygen barrier layer and the antireflection layer, the surface resistance of the coated glass is reduced to 5 Ω, and the resistance reduction rate is 67% compared with the prior art. At the same time, an efficient barrier with an average transmittance of 15.0% in the infrared band of 780 - 2500 nm is achieved. Meanwhile, the dielectric layer not only isolates the migration of Na ions in the glass substrate but also improves the stability of the light transmittance through the controllable antireflection effect. Combining with the single-sided coating process eliminates the risk of flipping damage in double-sided coating, and combining with the convective tempering process increases the product yield by more than 30%. It overcomes the mechanical damage risk and high energy consumption defects of the traditional double-sided coating process, and finally realizes the synergistic optimization of low sheet resistance, high infrared barrier, and mass production stability.

[0013] The concept, specific structure, and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, features, and effects of the present invention. Description of the Drawings

[0014] Figure 1 is a schematic diagram of the single-sided laminated AZO coated glass of the present invention; Figure 2 is a comparative schematic diagram of the infrared barrier effect of the single-sided laminated AZO coated glass of the present invention. Detailed Embodiments

[0015] The following introduces multiple preferred embodiments of the present invention with reference to the accompanying drawings of the specification to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0016] In the drawings, components with the same structure are denoted by the same reference numerals, and components with similar structures or functions are denoted by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. To make the illustration clearer, the thickness of some components in the drawings is appropriately exaggerated.

[0017] As shown in the figure, the present invention adopts the method of multi-layer stacking coating of the AZO functional layer on the same side of the glass to solve the deficiencies in the preparation method of the existing AZO double-sided coated glass.

[0018] The multi-layer stacking coating is as Figure 1 shown, and its specific preparation process is as follows: (1) Clean the glass substrate to ensure that the surface is free of any dirt; (2) The first stack of dielectric layers (1-1) is deposited on the glass surface by magnetron sputtering. The material used for the dielectric layer is one of silicon oxide, silicon nitride, titanium oxide, and zirconium oxide. The film thickness of the dielectric layer is 10-20 nm. The deposition conditions are as follows: the background vacuum is 2.0-6.0×10 -3 Pa, the substrate temperature is 40-80 °C, and the sputtering current density is 6-10 W / cm 2 , and the sputtering gas is oxygen and argon (the mixing ratio is 1:2 - 1:3). The sputtering method is one of DC, medium frequency, and radio frequency. The main functions of the dielectric layer are: Isolation: In addition to isolating the Na ions existing in the substrate itself in the single-layer structure and preventing the AZO functional layer from reacting with the Na ions, the dielectric layer also plays a role in isolating each AZO functional layer stack. Ensure that the film thickness of each AZO layer does not exceed 500 nm.

[0019] Antireflection: A suitable dielectric layer thickness can effectively improve the transmittance of the film layer itself, improve the color stability of the coated glass, and reduce the angular color difference.

[0020] (3) The first stack of AZO composite functional layers (1-2) is sputter-deposited by magnetron sputtering. The AZO composite functional layer includes a magnetron-sputtered Zn layer and a magnetron-sputtered AZO layer thereon.

[0021] The sputtering method of the magnetron-sputtered Zn layer is one of DC, medium frequency, and radio frequency. The sputtering conditions are as follows: the background vacuum is 2.0-6.0×10 -3 Pa, the substrate temperature is 40-80 °C, and the sputtering power density is 10-30 W / cm 2 , and the sputtering gas is argon; the film thickness of the Zn layer is 5-30 nm.

[0022] The sputtering method of the magnetron-sputtered AZO layer is one of DC, medium frequency, and radio frequency. The sputtering conditions are as follows: the background vacuum is 2.0-6.0×10 -3 Pa, the substrate temperature is 50-100 °C, and the sputtering power density is 10-30 W / cm 2 , and the sputtering gas is oxygen and argon with a mixing ratio of 1:8-1:10; the film thickness of the AZO layer is 300-500 nm.

[0023] (4) Steps (2) and (3) are repeated to deposit the second stack of dielectric layers (2-1) and AZO composite functional layers (2-2). In other embodiments, according to needs, more stacks can also be deposited continuously until the (i-1) and (i-2) layers.

[0024] (5) A composite structure coating layer is deposited on the laminated structure prepared in step (4) by magnetron sputtering. This layer includes an oxygen barrier layer and an antireflection layer.

[0025] The sputtering conditions for the oxygen barrier layer are as follows: the base vacuum is 2.0 - 6.0×10 -3 PA, the substrate temperature is 40 - 80 °C, the sputtering power density is 10 - 22 W / cm 2 , and the sputtering gases are nitrogen and argon (the mixing ratio is 3:1 - 3:2). The dense oxygen barrier layer can effectively isolate the AZO functional film from reacting with oxygen in the air, thereby increasing the durability of the film layer. It can also effectively improve the corrosion resistance and scratch resistance of the film layer. The material used for the barrier layer is one of silicon oxide, silicon nitride, zirconium oxide, titanium oxide, and zinc oxide tin, and the thickness is 30 - 100 nm. The sputtering method is one of DC, medium frequency, and RF.

[0026] The sputtering conditions for the antireflection layer are as follows: the base vacuum is 2.0 - 6.0×10 -3 PA, the substrate temperature is 40 - 80 °C, the sputtering power density is 8 - 15 W / cm 2 , and the sputtering gases are oxygen and argon (the mixing ratio is 1:2 - 1:3). The antireflection layer is generally used to increase the light transmittance, and the light transmittance of the film layer can be changed by increasing the thickness according to requirements. The material used for the antireflection layer is one of silicon oxide and magnesium fluoride. The thickness is 50 - 150 nm.

[0027] After testing, the present invention has the following advantages: 1. Significantly reduce the sheet resistance of the thin film: The surface resistance is about 5 Ω, far lower than 15 Ω of the existing single-sided coated products and 15 Ω of the online FTO glass, and better than 7 Ω of the double-sided coated products prepared by Chinese invention patent 2024107646117.

[0028] 2. High-efficiency infrared barrier: In the infrared band (780 - 2500 nm), the average transmittance of the single-sided laminated AZO coated product (two layers laminated) of the present invention is 15.0%, significantly lower than 37.8% of the existing online FTO glass, and better than 16.4% of the double-sided coated products prepared by Chinese invention patent 2024107646117, as Figure 2 shown.

[0029] Figure 2Among them, the double-sided coated product prepared by Chinese invention patent 2024107646117. It can be seen that the single-sided lamination adopted in the present invention has an effect similar to that of double-sided coating, but avoids the problem of needing to turn the glass over during the production process. Comparative example 2 is a single-layer AZO layer, but the thickness of this single-layer AZO layer is the same as that of the AZO layer in all the laminations of the product of the present invention. It can be seen that although the AZO layer thickness of the two is the same, the effect of the present invention is significantly better than that of comparative example 2. It can be seen that directly thickening the AZO composite functional layer cannot effectively improve the final heat insulation effect / reduce the film layer resistance. For a film layer that is too thick (exceeding 500 nm), Zn ions cannot effectively diffuse and combine with AZO during the annealing reaction, resulting in poor conductivity. After adding the dielectric layer, the AZO composite functional layer can be effectively limited to the range of 200-500 nm, so that the conductive performance of the film layer after lamination has an effect of 1+1>2.

[0030] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field according to the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. An infrared-blocking low sheet resistance AZO coated glass, characterized in that, Comprising: A glass substrate; n laminated structures sequentially deposited on one side of the glass substrate, where n ≥ 2; a composite coating layer covering the surface of the outermost laminated structure; Wherein: Each of the laminated structures includes a dielectric layer and an AZO composite functional layer. The AZO composite functional layer includes a Zn layer and an AZO layer, and the thickness of each AZO layer film does not exceed 500 nm; The composite coating layer includes an oxygen barrier layer and an antireflection layer.

2. The infrared-blocking low sheet resistance AZO-coated glass according to claim 1, wherein, The dielectric layer material is selected from one of silicon oxide, silicon nitride, titanium oxide, and zirconium oxide, with a thickness of 10 - 20 nm; the film thickness of the Zn layer is 5 - 30 nm; the oxygen barrier layer is selected from one of silicon oxide, silicon nitride, zirconium oxide, titanium oxide, and indium tin oxide, with a thickness of 30 - 100 nm; the antireflection layer material is silicon oxide or magnesium fluoride, with a thickness of 50 - 150 nm.

3. A method for preparing the coated glass as claimed in claim 2, characterized in that, Including: (a) Cleaning the glass substrate; (b) Alternately depositing at least two groups of dielectric layer / AZO composite functional layer laminates on one side of the glass; (c) Sequentially depositing an oxygen barrier layer and an antireflection layer on the laminate surface; Wherein both the dielectric layer and the AZO composite functional layer are deposited step by step using a magnetron sputtering process.

4. The infrared-blocking low sheet resistance AZO coated glass according to claim 3, wherein, The deposition conditions of the dielectric layer are as follows: the background vacuum degree is 2.0 - 6.0×10 -3 Pa, the substrate temperature is 40 - 80 °C, the sputtering power density is 6 - 10 W / cm 2 , the sputtering gas is a mixture of oxygen and argon with a mixing ratio of 1:2 - 1:3; the sputtering method is one of DC, medium frequency, and radio frequency.

5. The infrared-blocking low sheet resistance AZO-coated glass according to claim 3, wherein, The sputtering method of the magnetron sputtered Zn layer is one of DC, medium frequency, and radio frequency. The sputtering conditions are as follows: the background vacuum degree is 2.0 - 6.0×10 -3 Pa, the substrate temperature is 40 - 80°C, the sputtering power density is 10 - 30 W / cm 2 , and the sputtering gas is argon.

6. The infrared barrier low sheet resistance AZO coated glass according to claim 3, wherein, The sputtering method of the magnetron sputtered AZO layer is one of DC, medium frequency and radio frequency, and the sputtering conditions are as follows: the background vacuum degree is 2.0 - 6.0×10 -3 Pa, the substrate temperature is 50 - 100 °C, the sputtering power density is 10 - 30 W / cm 2 , and the sputtering gas is a mixture of oxygen and argon with a mixing ratio of 1:8 - 1:

10.

7. The infrared-blocking low sheet resistance AZO coated glass according to claim 3, wherein, The sputtering conditions of the oxygen barrier layer are as follows: the base vacuum is 2.0 - 6.0×10 -3 Pa, the substrate temperature is 40 - 80 °C, the sputtering power density is 10 - 22 W / cm 2 , and the sputtering gas is a mixture of nitrogen and argon with a mixing ratio of 3:1 - 3:

2.

8. The infrared-blocking low sheet resistance AZO-coated glass according to claim 3, wherein, The sputtering conditions of the antireflection layer are as follows: the base vacuum degree is 2.0 - 6.0×10 -3 PA, the substrate temperature is 40 - 80 °C, and the sputtering power density is 8 - 15 W / cm 2 , and the sputtering gas is a mixture of oxygen and argon with a mixing ratio of 1:2 - 1:3.

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