CN106399940B - A kind of solar energy thermal-power-generating reflecting mirror SiO2-Ag-SiO2Composite membrane and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of production and manufacture of materials for solar thermal power generation reflectors. A kind of SiO ₂ -Ag-SiO ₂ composite film for solar thermoelectric reflector, it is characterized in that, it comprises glass substrate and the film layer that is formed on the glass substrate; Film layer is made of transition layer, reflection layer and protective layer, transition layer, reflective layer and protective layer are arranged outwards from the surface of the glass substrate in sequence, and the transition layer, reflective layer and protective layer are all made by radio frequency magnetron sputtering; the material of the transition layer is SiO ₂ with a thickness of 20nm ‑50nm; the reflective layer is made of Ag with a thickness of 100nm‑200nm; the protective layer is made of SiO ₂ with a thickness of 50nm‑150nm. The composite film obtained by the method has the characteristics of high reflectivity, good adhesion and long outdoor service life.

Description

SiO2-Ag-SiO2 Composite Film for Solar Thermal Power Mirror and Its Preparation method

technical field

The invention relates to the technical field of manufacturing materials for solar thermal power generation mirrors, in particular to a SiO ₂ -Ag-SiO ₂ composite film for solar thermal power generation mirrors and a preparation method thereof.

Background technique

With the shortage of energy and the aggravation of environmental problems worldwide, the research, development and utilization of renewable energy, mainly solar energy, have been paid more and more attention. Solar power generation is mainly divided into photovoltaic power generation and photothermal power generation. Photovoltaic power generation has developed rapidly in the past few decades. In recent years, solar thermal power generation has attracted attention due to its many advantages such as good efficiency, clean and pollution-free, stable operation, and easy integration into the power grid. Experts predict that in the near future, the capacity of photothermal power generation will far exceed that of photovoltaics, and it may replace conventional energy sources and be widely used by humans. The economic viability of solar thermal power systems that use large solar mirrors to collect solar energy to generate electricity depends largely on the development of durable, highly reflective mirror systems that are inexpensive to produce. Photothermal power stations are mostly built in areas with sufficient sunlight and strong solar radiation, such as the vast Gobi and deserts in western my country, but the environment in these areas is relatively harsh, so the life of the reflectors in the solar thermal power generation system will determine the cost of the power station. Therefore, mirrors with high reflectivity, good adhesion and long service life are the focus of current research.

Since silver has a high reflectivity in the infrared region, it has great potential as a material for high-performance mirror coatings. However, there is a big problem to be considered when silver films are used as reflective materials, namely Durability cannot be guaranteed, because the mechanical strength and chemical stability of the silver film are not good, it is easy to be oxidized or vulcanized, and loses luster, which will lead to a decrease in reflectivity, so it is necessary to coat a protective film on the silver film Less. In addition, because the adhesion of Ag to the glass substrate is relatively poor, and it is easy to be corroded and peeled off in some special atmospheres, which affects its performance. Therefore, in practical applications, it is necessary to plate a layer between the two. Dielectric layer to improve the adhesion of the reflective layer to the substrate. However, if the thickness of the protective film cannot be effectively controlled, it will also affect the improvement of reflectivity.

In order to obtain reflective materials for mirrors with high reflectivity, good adhesion, and long service life, researchers have carried out a series of studies. Zhao Yongzan and others studied the problem of adhesion during the preparation of solar concentrator films. Before evaporating aluminum film, a thin layer of chromium film was evaporated on the surface of the substrate, because chromium would be removed from the oxide substrate It captures oxygen and forms an oxide, which has a strong chemical bond, so the adhesion of the concentrator film layer is greatly improved. Tetsuya Goto used the sputtering method to prepare silver films on cycloolefin polymers and silicon dioxide respectively, and used Si ₃ N ₄ films as protective layers to obtain reflective films with high reflectivity and good durability. Kennedy etc. adopt aluminum oxide as the protective layer, and silver as the surface reflection layer, so that the reflectivity of sunlight reaches 95%. Xu Yongjun and others used nano-silver as the surface reflection layer, and the reflectivity of sunlight reached 96.74%. Chinese patent (patent publication number: CN102260854A) discloses a kind of self-cleaning solar energy high reflectivity nano-film and its manufacturing method, when the reflective film is silver film, the reflectivity to sunlight is 94%～97%, when the reflective film is For aluminum film, the reflectance is 90% to 92%. Chinese patent (patent publication number: CN104681662A) discloses a method for preparing a high-reflectivity solar film. When the thickness of the silver film is 130nm and the thickness of silicon dioxide is 320nm, the film reflectance is the highest, and the reflectance of sunlight and visible light is the highest. They are 96.66% and 98.84% respectively, and the wear resistance and aging resistance of the film material are good.

Contents of the invention

The technical problem to be solved by the present invention is: in order to avoid the defects and deficiencies in the prior art, the present invention provides a SiO ₂ -Ag-SiO ₂ composite film for solar thermal power generation mirrors and a preparation method thereof. The composite film obtained by the method has the characteristics of high reflectivity, good adhesion and long outdoor service life.

The technical solution provided by the present invention is: a SiO ₂ -Ag-SiO ₂ composite film for solar thermal power generation mirror, characterized in that it includes a glass substrate 1 and a film layer formed on the glass substrate; the film layer consists of a transition layer (or called dielectric layer), reflective layer and protective layer, the transition layer, reflective layer and protective layer are arranged from the surface of the glass substrate 1 outwards in sequence, and the transition layer, reflective layer and protective layer are all made by radio frequency magnetron sputtering The material of the transition layer 2 is SiO ₂ with a thickness of 20nm-50nm; the material of the reflective layer 3 is Ag with a thickness of 100nm-200nm; the material of the protective layer 4 is SiO ₂ with a thickness of 50nm-150nm.

The above-mentioned method for preparing a SiO ₂ -Ag-SiO ₂ composite film for a solar thermal power generation reflector is characterized in that it comprises the following steps:

1) Select an ordinary glass slide (as the substrate), wash it with detergent several times (such as 2-5 times), wash off the impurities (dirty) on the surface, then rinse it with tap water, and then put it into deionized water for ultrasonic cleaning 10-30min, and finally put into absolute ethanol [99.99% (mass), analytically pure] and ultrasonically clean for 10-30min to obtain a glass substrate; store the cleaned glass substrate in absolute ethanol [99.99% (mass), analyze Pure] for standby;

2) Prepare a transition layer (or dielectric layer) on a glass substrate (or glass substrate): the method is to use radio frequency magnetron sputtering deposition, and the size of the _SiO2 target is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 0.5-1.5Pa, and the target base distance is fixed at 60-100mm. The argon flow rate is 40sccm, the sputtering power is 100-200W, and the sputtering time is 10-30min; a transition layer is obtained on the glass substrate;

3) Prepare the reflective layer on the transition layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the reflective layer is silver, and the target size of silver is The purity is 99.99wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 0.5-1.5Pa, and the target base distance is fixed at 60-100mm. The argon flow rate is 40sccm, the sputtering power is 100-200W, and the sputtering time is 10-30min;

4) Prepare a protective layer on the reflective layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the protective layer is SiO ₂ , and the target size is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 0.5-1.5Pa, and the target base distance is fixed at 60-100mm. The argon flow rate is 40 sccm, the sputtering power is 100-200 W, and the sputtering time is 20-40 min; the SiO ₂ -Ag-SiO ₂ composite film for solar thermoelectric mirrors is obtained.

In steps 2), 3), and 4), the target needs to be pre-sputtered for 5 minutes before sputtering to remove residual oxides and pollutants on the target surface.

The infrared reflectance of the film structure prepared by the method can reach 99.73%, and due to the anti-reflection effect of the _SiO2 film, the infrared reflectance can exceed 100%.

Using the peeling test, referring to the adhesion test standard GBT9286-1998, the adhesion can reach level 0 (a total of 6 levels, of which level 0 means the best adhesion, and level 5 means the worst adhesion).

Compared with the prior art, the present invention has the following advantages: (1) The film structure obtained by the present invention has an infrared reflectivity of over 99.73%. (2) There is good adhesion between the film layers, especially between the film layer and the glass substrate. Referring to the adhesion test standard GBT9286-1998, the adhesion can reach level 0 (a total of 6 levels, of which level 0 means the best adhesion) Well, level 5 means the worst adhesion), and it has a long service life in the harsh environment where the solar thermal power station is located. (3) The process route is simple, suitable for large-scale industrial production, which not only saves costs, but also saves maintenance costs and reduces environmental pollution.

Description of drawings

Fig. 1 is a schematic diagram of a SiO ₂ -Ag-SiO ₂ composite film for a solar thermal power generation reflector according to the present invention.

Fig. 2 is a reflectance diagram of the SiO ₂ -Ag-SiO ₂ composite film in Example 1 of the present invention.

Fig. 3 is a photo of adhesion test of a SiO ₂ -Ag-SiO ₂ composite film for a solar thermal power generation reflector according to Example 1 of the present invention: wherein, a is the picture before the test, and b is the picture after the test.

Fig. 4 is a reflectance diagram of the SiO ₂ -Ag-SiO ₂ composite film in Example 2 of the present invention.

Fig. 5 is a reflectance diagram of the SiO ₂ -Ag-SiO ₂ composite film in Example 3 of the present invention.

Fig. 6 is a reflectance diagram of the SiO ₂ -Ag-SiO ₂ composite film in Example 4 of the present invention.

Fig. 7 is a reflectance diagram of the SiO ₂ -Ag-SiO ₂ composite film in Example 5 of the present invention.

Fig. 8 is a reflectance diagram of the SiO ₂ -Ag-SiO ₂ composite film in Example 6 of the present invention.

In Fig. 1: 1 is a glass substrate, 2 is a transition layer, 3 is a reflective layer, and 4 is a protective layer.

Detailed ways

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with examples, but the present invention is not limited only to the following examples.

Example 1:

A method for preparing a SiO ₂ -Ag-SiO ₂ composite film for a solar thermoelectric mirror, comprising the following steps:

1) Select an ordinary glass slide (as the substrate), wash it with detergent several times (such as 2-5 times), wash off the impurities (dirty) on the surface, then rinse it with tap water, and then put it into deionized water for ultrasonic cleaning 20min, and finally put it into absolute ethanol [99.99% (mass), analytically pure] and ultrasonically clean it for 20min to obtain glass substrate 1; store the cleaned glass substrate in absolute ethanol [99.99% (mass), analytically pure] spare;

2) Prepare a transition layer (or dielectric layer) on a glass substrate (or glass substrate): the method is to use radio frequency magnetron sputtering deposition, and the size of the _SiO2 target is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 0.5Pa, the target base distance is fixed at 60mm, and the argon flow rate is 40sccm , the sputtering power is 100W, and the sputtering time is 10min; a transition layer (SiO ₂ film) 2 is obtained on the glass substrate 1, and the SiO ₂ film thickness is 30nm;

3) Prepare the reflective layer on the transition layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the reflective layer is silver, and the target size of silver is The purity is 99.99wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 108W, and the sputtering time is 20min, and the reflection layer 3 (silver film) is obtained on the transition layer 2, and the thickness of the silver film is 110nm;

4) Prepare a protective layer on the reflective layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the protective layer is SiO ₂ , and the target size is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 0.5Pa, the target base distance is fixed at 60mm, and the argon flow rate is 40sccm , the sputtering power is 100W, the sputtering time is 20min, and the thickness of the SiO ₂ film is 55nm; the SiO ₂ -Ag-SiO ₂ composite film for solar thermoelectric mirrors is obtained.

In steps 2), 3), and 4), the target needs to be pre-sputtered for 5 minutes before sputtering to remove residual oxides and pollutants on the target surface.

The SiO ₂ -Ag-SiO ₂ composite film for the solar thermal power generation mirror obtained in Example 1 is shown in Figure 1, and the film includes in order:

Glass substrate 1; transition layer (SiO ₂ film) 2, made of SiO ₂ , with a thickness of 30nm; reflective layer 3, made of Ag, with a thickness of 110nm, and a protective layer 4, made of SiO ₂ , with a thickness of 55nm.

The infrared reflectance of the SiO ₂ -Ag-SiO ₂ composite film system obtained in Example 1 is higher than 99.76%, and due to the anti-reflection effect of the SiO ₂ film, the infrared reflectance even exceeds 100%, and the adhesion can reach Level 0, long service life outdoors.

Example 2:

A method for preparing a SiO ₂ -Ag-SiO ₂ composite film for a solar thermoelectric mirror, comprising the following steps:

1) Select an ordinary glass slide (as the substrate), wash it with detergent several times (such as 2-5 times), wash off the impurities (dirty) on the surface, then rinse it with tap water, and then put it into deionized water for ultrasonic cleaning After 20 minutes, put it into absolute ethanol [99.99% (mass), analytically pure] and ultrasonically clean it for 20 minutes to obtain a glass substrate; store the cleaned glass substrate in absolute ethanol [99.99% (mass), analytically pure] for later use ;

2) Prepare a transition layer (or dielectric layer) on a glass substrate (or glass substrate): the method is to use radio frequency magnetron sputtering deposition, and the size of the _SiO2 target is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 150W, and the sputtering time is 20min; a transition layer (SiO ₂ film) 2 is obtained on the glass substrate 1, and the SiO ₂ film thickness is 40nm;

3) Prepare the reflective layer on the transition layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the reflective layer is silver, and the target size of silver is The purity is 99.99wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 108W, and the sputtering time is 20min, and the reflection layer 3 (silver film) is obtained on the transition layer 2, and the thickness of the silver film is 110nm;

4) Prepare a protective layer on the reflective layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the protective layer is SiO ₂ , and the target size is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 150W, the sputtering time is 30min, and the protective layer (SiO ₂ film) is obtained, and the thickness of the SiO ₂ film is 102nm; finally, the SiO ₂ -Ag-SiO ₂ composite film for the solar thermoelectric mirror is obtained.

In steps 2), 3), and 4), the target needs to be pre-sputtered for 5 minutes before sputtering to remove residual oxides and pollutants on the target surface.

The infrared reflectivity of the SiO ₂ -Ag-SiO ₂ composite film system obtained in Example 2 is higher than 99.81%, and due to the anti-reflection effect of the SiO ₂ film, the infrared reflectivity even exceeds 100%, and the adhesion can reach Level 0, long service life outdoors.

Example 3:

A method for preparing a SiO ₂ -Ag-SiO ₂ composite film for a solar thermoelectric mirror, comprising the following steps:

1) Select an ordinary glass slide (as the substrate), wash it with detergent several times (such as 2-5 times), wash off the impurities (dirty) on the surface, then rinse it with tap water, and then put it into deionized water for ultrasonic cleaning After 20 minutes, put it into absolute ethanol [99.99% (mass), analytically pure] and ultrasonically clean it for 20 minutes to obtain a glass substrate; store the cleaned glass substrate in absolute ethanol [99.99% (mass), analytically pure] for later use ;

2) Prepare a transition layer (or dielectric layer) on a glass substrate (or glass substrate): the method is to use radio frequency magnetron sputtering deposition, and the size of the _SiO2 target is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.5Pa, the target base distance is fixed at 100mm, and the argon flow rate is 40sccm , the sputtering power is 200W, and the sputtering time is 30min; a transition layer (SiO ₂ film) is obtained on the glass substrate, and the SiO ₂ film thickness is 50nm;

3) Prepare the reflective layer on the transition layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the reflective layer is silver, and the target size of silver is The purity is 99.99wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 108W, and the sputtering time is 20min, and the reflection layer 3 (silver film) is obtained on the transition layer 2, and the thickness of the silver film is 110nm;

4) Prepare a protective layer on the reflective layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the protective layer is SiO ₂ , and the target size is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.5Pa, the target base distance is fixed at 100mm, and the argon flow rate is 40sccm , the sputtering power was 200W, the sputtering time was 40min, and the thickness of the SiO ₂ film was 139nm; a SiO ₂ -Ag-SiO ₂ composite film for solar thermoelectric mirrors was obtained.

In steps 2), 3), and 4), the target needs to be pre-sputtered for 5 minutes before sputtering to remove residual oxides and pollutants on the target surface.

The infrared reflectance of the SiO ₂ -Ag-SiO ₂ composite film system obtained in Example 3 is higher than 99.90%, and due to the anti-reflection effect of the SiO ₂ film, the infrared reflectance even exceeds 100%, and the adhesion can reach Level 0, long service life outdoors.

Example 4:

A method for preparing a SiO ₂ -Ag-SiO ₂ composite film for a solar thermoelectric mirror, comprising the following steps:

1) Select an ordinary glass slide (as the substrate), wash it with detergent several times (such as 2-5 times), wash off the impurities (dirty) on the surface, then rinse it with tap water, and then put it into deionized water for ultrasonic cleaning After 20 minutes, put it into absolute ethanol [99.99% (mass), analytically pure] and ultrasonically clean it for 20 minutes to obtain a glass substrate; store the cleaned glass substrate in absolute ethanol [99.99% (mass), analytically pure] for later use ;

2) Prepare a transition layer (or dielectric layer) on a glass substrate (or glass substrate): the method is to use radio frequency magnetron sputtering deposition, and the size of the _SiO2 target is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 150W, and the sputtering time is 20min; a transition layer (SiO ₂ film) is obtained on the glass substrate, and the SiO ₂ film thickness is 40nm;

3) Prepare the reflective layer on the transition layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the reflective layer is silver, and the target size of silver is The purity is 99.99wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 160W, and the sputtering time is 20min, and the reflection layer 3 (silver film) is obtained on the transition layer 2, and the thickness of the silver film is 150nm;

4) Prepare a protective layer on the reflective layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the protective layer is SiO ₂ , and the target size is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power was 150W, the sputtering time was 30min, and the thickness of the SiO ₂ film was 102nm; a SiO ₂ -Ag-SiO ₂ composite film for solar thermal power mirrors was obtained.

In steps 2), 3), and 4), the target needs to be pre-sputtered for 5 minutes before sputtering to remove residual oxides and pollutants on the target surface.

The SiO ₂ -Ag-SiO ₂ composite film system infrared reflectance obtained in Example 4 is higher than 99.87%, and due to the anti-reflection effect of the SiO ₂ film, the infrared reflectance even exceeds 100%, and the adhesion can reach Level 0, long service life outdoors.

Example 5:

A method for preparing a SiO ₂ -Ag-SiO ₂ composite film for a solar thermoelectric mirror, comprising the following steps:

1) Select an ordinary glass slide (as the substrate), wash it with detergent several times (such as 2-5 times), wash off the impurities on the surface and rinse it with tap water, then put it into deionized water for ultrasonic cleaning for 10 minutes, and finally put it on Put into absolute ethanol [99.99% (mass), analytically pure] and ultrasonically clean for 10 minutes to obtain a glass substrate; store the cleaned glass substrate in absolute ethanol [99.99% (mass), analytically pure] for subsequent use;

2) Prepare a transition layer (or dielectric layer) on a glass substrate (or glass substrate): the method is to use radio frequency magnetron sputtering deposition, and the size of the _SiO2 target is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 150W, and the sputtering time is 20min; a transition layer (SiO ₂ film) is obtained on the glass substrate, and the SiO ₂ film thickness is 40nm;

3) Prepare the reflective layer on the transition layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the reflective layer is silver, and the target size of silver is The purity is 99.99wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.5Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 160W, and the sputtering time is 30min, and the reflection layer 3 (silver film) is obtained on the transition layer 2, and the thickness of the silver film is 200nm;

4) Prepare a protective layer on the reflective layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the protective layer is SiO ₂ , and the target size is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power was 150W, the sputtering time was 230min, and the thickness of the SiO ₂ film was 102nm; a SiO ₂ -Ag-SiO ₂ composite film for a solar thermoelectric mirror was obtained.

In steps 2), 3), and 4), the target needs to be pre-sputtered for 5 minutes before sputtering to remove residual oxides and pollutants on the target surface.

The infrared reflectance of the SiO ₂ -Ag-SiO ₂ composite film system obtained in Example 5 is higher than 99.82%, and due to the anti-reflection effect of the SiO ₂ film, the infrared reflectance even exceeds 100%, and the adhesion can reach Level 0, long service life outdoors.

Embodiment 6:

A method for preparing a SiO ₂ -Ag-SiO ₂ composite film for a solar thermoelectric mirror, comprising the following steps:

1) Select an ordinary glass slide (as the substrate), wash it with detergent for several times (such as 2-5 times), wash off the impurities on the surface and then rinse it with tap water, then put it into deionized water for ultrasonic cleaning for 30 minutes, and finally put it on Put into absolute ethanol [99.99% (mass), analytically pure] and ultrasonically clean for 30 minutes to obtain a glass substrate; store the cleaned glass substrate in absolute ethanol [99.99% (mass), analytically pure] for subsequent use;

2) Prepare a transition layer (or dielectric layer) on a glass substrate (or glass substrate): the method is to use radio frequency magnetron sputtering deposition, and the size of the _SiO2 target is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 1.0Pa, the target base distance is fixed at 80mm, and the argon flow rate is 40sccm , the sputtering power is 150W, and the sputtering time is 10-30min; a transition layer (SiO ₂ film) is obtained on the glass substrate, and the SiO ₂ film thickness is 40nm;

3) Prepare the reflective layer on the transition layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the reflective layer is silver, and the target size of silver is The purity is 99.99wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 0.5Pa, the target base distance is fixed at 60mm, and the argon flow rate is 40sccm , the sputtering power is 100W, and the sputtering time is 30min, and the reflection layer 3 (silver film) is obtained on the transition layer 2, and the thickness of the silver film is 200nm;

4) Prepare a protective layer on the reflective layer: the method is to use radio frequency magnetron sputtering deposition method, the material of the protective layer is SiO ₂ , and the target size is The purity is 99.999wt%, the sputtering gas is high-purity argon with a volume fraction of 99.999%, the vacuum degree of the sputtering chamber is 4.0×10 ^-4 Pa, the working pressure is 0.5Pa, the target base distance is fixed at 60mm, and the argon flow rate is 40sccm , the sputtering power is 100W, the sputtering time is 20min, and the thickness of the SiO ₂ film is 137nm; the SiO ₂ -Ag-SiO ₂ composite film for solar thermal power mirrors is obtained.

In steps 2), 3), and 4), the target needs to be pre-sputtered for 5 minutes before sputtering to remove residual oxides and pollutants on the target surface.

The SiO ₂ -Ag-SiO ₂ composite film system infrared reflectance obtained in Example 6 is higher than 99.89%, and due to the anti-reflection effect of the SiO ₂ film, the infrared reflectance even exceeds 100%, and the adhesion can reach Level 0, long service life outdoors.

As well as the upper and lower limits and interval values of various process parameters of the present invention (such as air pressure, target base distance, sputtering power, time, etc.), the present invention can be realized, and the embodiments are not listed one by one here.

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some deduction or replacement can also be made, which should be regarded as the protection scope of the present invention.

Claims (3)

1. a kind of solar energy thermal-power-generating reflecting mirror SiO₂-Ag-SiO₂Composite membrane, which is characterized in that it include glass substrate and The film layer being formed on glass substrate；Film layer is made of transition zone, reflecting layer and protective layer, transition zone, reflecting layer and protective layer It is successively arranged outward from the surface of glass substrate, transition zone, reflecting layer, protective layer are made by radio-frequency magnetron sputter method； The material of the transition zone is SiO₂, with a thickness of 20nm-50nm；The material in the reflecting layer is Ag, with a thickness of 100nm- 200nm；The material of the protective layer is SiO₂, with a thickness of 50nm-150nm.

2. a kind of solar energy thermal-power-generating reflecting mirror SiO as described in claim 1₂-Ag-SiO₂The preparation method of composite membrane, Be characterized in that the following steps are included:

1) common glass slide is chosen, is cleaned multiple times with dish washing liquid, the impurity on surface is washed off and then is washed away completely with tap water, then is put Enter ultrasonic cleaning 10-30min in deionized water, is finally putting into ultrasonic cleaning 10-30min in dehydrated alcohol, obtains glass Substrate；Cleaned glass substrate is stored in spare in dehydrated alcohol；

2) prepare transition zone on the glass substrate: method is with r. f. magnetron sputtering mode, SiO₂Target size is Φ 76.2 × 5mm, purity 99.999wt%, sputter gas are the high-purity argon that volume fraction is 99.999%, and sputtering chamber vacuum degree is 4.0 ×10^-4Pa, operating air pressure 0.5-1.5Pa, target-substrate distance are fixed on 60-100mm, and argon flow is 40sccm, and sputtering power is 100-200W, sputtering time 10-30min；A transition zone is obtained on the glass substrate；

3) reflecting layer is prepared on transition zone: method is to use r. f. magnetron sputtering mode, and the material in reflecting layer is silver, silver-colored Target size is 45 × 4mm of Φ, and purity 99.99wt%, sputter gas is the high-purity argon that volume fraction is 99.999%, sputtering Room vacuum degree is 4.0 × 10^-4Pa, operating air pressure 0.5-1.5Pa, target-substrate distance are fixed on 60-100mm, and argon flow is 40sccm, Sputtering power is 100-200W, sputtering time 10-30min；

4) protective layer is prepared on reflecting layer: method is to use r. f. magnetron sputtering mode, and the material of protective layer is SiO₂, target Material is the high-purity argon that volume fraction is 99.999% having a size of 76.2 × 5mm of Φ, purity 99.999wt%, sputter gas, is splashed Penetrating room vacuum degree is 4.0 × 10^-4Pa, operating air pressure 0.5-1.5Pa, target-substrate distance are fixed on 60-100mm, and argon flow is 40sccm, sputtering power 100-200W, sputtering time 20-40min；Obtain solar energy thermal-power-generating reflecting mirror SiO₂-Ag- SiO₂Composite membrane.

3. a kind of solar energy thermal-power-generating reflecting mirror SiO according to claim 2₂-Ag-SiO₂The preparation method of composite membrane, It is characterized by: in step 2), 3), 4) in, be both needed to carry out 5 minutes pre-sputterings to target before sputtering.