CN105206691A - Stainless steel foil solar cell with back protective layer and preparation method thereof - Google Patents

Abstract

The invention relates to the field of solar cells, and specifically discloses a stainless steel foil solar cell with a back protective layer and a preparation method thereof. In the stainless steel foil solar cell with a back protection layer of the present invention, a diffusion barrier layer, a first electrode layer, an absorption layer, a buffer layer, a second electrode layer, an antireflection layer and a surface electrode layer are sequentially formed on the solar receiving side of the substrate, A back protection layer is formed on the side opposite to the solar energy receiving side of the substrate, the back protection layer is a single layer, and the diffusion barrier layer is a three-layer or more than three-layer structure. In the stainless steel foil solar cell with a back protective layer of the present invention, the back protective layer can effectively avoid damage to the substrate in the high-temperature corrosive atmosphere process, the diffusion barrier layer can effectively prevent the impurity elements of the substrate from entering the absorption layer, and the diffusion barrier layer can be significantly increased. The bonding force with the substrate and the first electrode layer.

Description

Stainless steel foil solar cell with back protection layer and preparation method thereof

technical field

The invention belongs to the technical field of solar cells, in particular to a stainless steel foil solar cell with a back protective layer and a preparation method thereof.

Background technique

With the continuous increase of human energy consumption, the depletion of non-renewable energy sources such as fossil fuels has become an urgent problem to be solved. The total consumption of fossil energy will reach an inflection point around 2030, and the proportion of renewable energy will continue to rise. Among them, the proportion of solar energy in the future energy structure will become larger and larger. It is conservatively estimated that this proportion will exceed 60% in 2100. . Solar energy is the most abundant energy among many renewable energy sources. The energy of global sunlight for one hour is equivalent to the energy consumption of the earth for a year, which is much higher than wind energy, geothermal energy, hydropower, ocean energy, biomass energy and other energy sources.

An important development direction of solar cells is multi-purpose flexible substrate solar cells. The difference from conventional solar cells that use rigid materials (glass, etc.) as substrates is that the substrate materials of flexible solar cells are soft, bendable metal foils or organic polymer materials, such as stainless steel foil, aluminum foil, polyimide film, etc. . Flexible solar cell is a high-end photovoltaic product, which has the following obvious advantages: (1) The battery module can be bent and is suitable for non-planar installation conditions; (2) The battery module is light in weight and has a high mass specific power; The bottom material consumption is small and the cost is low.

As a flexible substrate solar cell, stainless steel foil breaks away from the traditional substrate material glass, making it light and bendable, but it also brings new problems. Glass has high strength and stability under relatively high temperature (<600°C) atmosphere, so it can play an effective support and protection role in the growth process of various thin film solar cells. For stainless steel foil, it will be severely corroded by the atmosphere containing sulfur, selenium, oxygen, chlorine and other elements at high temperature, and polymer materials are more likely to decompose and denature at high temperature, and cannot exist as a stable substrate. Therefore, a core key issue in stainless steel foil solar cell technology is to develop a protection method for the substrate, so that it can maximize the protection of the substrate while maintaining its flexible characteristics, and resist high-temperature corrosive atmosphere and external mechanical damage. At the same time, due to the large amount of elements in the stainless steel foil substrate, such as Fe, it is easy to diffuse to the absorber layer through the metal electrode in the high temperature process of battery preparation, resulting in deep level doping of the absorber layer, which greatly affects the photoelectric performance of the battery. However, this effect is almost negligible for soda-lime glass substrates. Therefore, stainless steel foil solar cells require a highly chemically stable barrier layer to prevent the diffusion of harmful elements like Fe.

Patent CN102386248A discloses a solar cell structure and a method of manufacturing a solar cell, the solar cell includes: a semiconductor substrate; a passivation film disposed on one side of the semiconductor substrate; a protective layer disposed on the passivation film on a side of the protective layer opposite to the semiconductor substrate; and an electrode disposed on a side of the protective layer opposite to the passivation film. Wherein, the protective layer is a material whose absolute value of Gibbs free energy is smaller than the absolute value of Gibbs free energy of each component of the glass frit, including copper, palladium, iridium, their alloys, their oxidation objects or a combination of them. Among these materials, copper-containing materials have high activity and limited protection performance, while palladium and iridium-based materials are rare and precious metals with high cost, which is not conducive to large-scale industrial development and cost control of commercial products.

Patent CN101268608A discloses a photovoltaic device with a conductive barrier layer and with an aluminum foil substrate. The barrier layer disclosed in this patent is suitable for aluminum foil substrates, but not for other flexible substrates, such as stainless steel foil substrates and the like. The reason is that the thermal expansion coefficient of stainless steel foil is different from that of aluminum foil, so the diffusion barrier layer suitable for aluminum foil cannot adapt to the stainless steel foil substrate, which often leads to insufficient bonding force between the diffusion barrier layer and the stainless steel foil substrate.

Therefore, it is still necessary to effectively protect the stainless steel foil substrate and prevent the impurity elements of the stainless steel foil substrate from diffusing to the absorbing layer through the metal electrode in the high temperature process, and to further strengthen the bonding force between the barrier layer, the stainless steel foil substrate and the first electrode layer. Explore further.

Contents of the invention

The main purpose of the present invention is to solve the problems in the above-mentioned prior art that the base of the stainless steel foil solar cell is easily corroded, easily decomposed and denatured at high temperature, and the blocking effect and bonding force of the diffusion barrier layer are not ideal, and to provide a A stainless steel foil solar cell with a back protective layer and a preparation method thereof.

In order to realize the foregoing invention object, the technical scheme that the present invention adopts is as follows:

A stainless steel foil solar cell with a back protection layer, comprising a stainless steel foil substrate and a diffusion barrier layer, a first electrode layer, an absorber layer, a buffer layer, a second electrode layer, an antireflection layer and a surface electrode layer sequentially formed on the stainless steel foil substrate ,

The opposite side of the solar receiving side of the stainless steel foil substrate is formed with a back protection layer, the back protection layer is a single layer, and the back protection layer is optionally made of the following group:

Group a: aluminium, molybdenum, titanium, nickel, copper, zirconium, niobium, chromium, ruthenium, rhodium, palladium, tantalum, tungsten, iridium, osmium, platinum, gold or silver, or alloys thereof; or

Group b: nitrides, oxides or carbides of silicon; or

Group c: titanium nitride, tantalum nitride, tungsten nitride or zirconium nitride;

The thickness of the back protection layer is 10nm to 3000nm;

The diffusion barrier layer is a structure of three or more layers, and each layer of the diffusion barrier layer is optionally made of the following groups:

Group A: aluminium, molybdenum, titanium, nickel, copper, zirconium, niobium, chromium, ruthenium, rhodium, palladium, tantalum, tungsten, iridium, osmium, platinum, gold or silver, or alloys thereof; or

Group B: Nitrides, oxides or carbides of silicon; or

Group C: titanium nitride, tantalum nitride, tungsten nitride or zirconium nitride;

The thickness of the diffusion barrier layer is 10nm-3000nm.

In the stainless steel foil solar cell with a back protection layer of the present invention, the back protection layer is formed on the opposite side of the solar energy receiving side of the stainless steel foil substrate, and the composition of the back protection layer is screened, and the diffusion barrier layer of the multilayer structure is selected at the same time, and the selection The composition of the diffusion barrier layer, the stainless steel foil solar cell with the back protection layer obtained in the present invention, the back protection layer can effectively prevent the damage to the stainless steel foil substrate in the high temperature corrosive atmosphere process, and the diffusion barrier layer can not only effectively prevent the stainless steel foil substrate from The impurity elements can enter the absorption layer, and the bonding force between the barrier layer and the stainless steel foil substrate and the first electrode layer can be effectively improved.

Preferably, in the aforementioned stainless steel foil solar cell with a back protection layer, the first electrode layer is a molybdenum thin film layer.

Preferably, in the aforementioned stainless steel foil solar cell with a back protection layer, the back protection layer is made of silicon nitride, silicon oxide, silicon carbide, titanium nitride, tantalum nitride, tungsten nitride or zirconium nitride. By screening the aforementioned compounds, the damage to the stainless steel foil substrate in the high-temperature corrosive atmosphere process can be effectively avoided, and no more impurities will be brought to the stainless steel foil substrate, and the acquisition method is simple and the production cost is low.

Preferably, in the aforementioned stainless steel foil solar cell with a back protection layer, the diffusion barrier layer is a three-layer structure, including a layer close to the base, an intermediate layer and a layer close to the first electrode. In the stainless steel foil solar cell with a back protective layer of the present invention, the diffusion barrier layer adopts a preferred three-layer structure, which can not only effectively prevent impurity elements such as nickel, manganese, and iron of the stainless steel foil from entering the absorption layer, but also effectively improve the relationship between the diffusion barrier layer and the stainless steel. Bonding force between the foil substrate and the first electrode layer.

Preferably, in the aforementioned stainless steel foil solar cell with a back protective layer, the middle layer of the diffusion barrier layer is made of any one of titanium nitride, tantalum nitride, tungsten nitride or zirconium nitride. By optimizing the aforementioned composition of the intermediate layer, elements such as nickel, iron, and manganese in stainless steel can be effectively prevented from diffusing into the absorbing layer during the high-temperature preparation process of the copper indium gallium selenide battery, thereby affecting the performance of the battery.

Preferably, in the aforementioned stainless steel foil solar cell with a back protective layer, the layer near the base of the diffusion barrier layer is made of titanium, chromium, titanium nitride or tantalum nitride. The inventor found through a lot of research that the coefficient of thermal expansion of titanium, chromium, titanium nitride and tantalum nitride is close to that of stainless steel, so the bonding force with stainless steel is the best, and these materials do not interact with selenium during the high-temperature preparation process of solar cells. The chemical reaction will not affect the performance of the battery and the bonding force of the film layer.

Preferably, in the aforementioned stainless steel foil solar cell with a back protective layer, the layer of the diffusion barrier layer close to the first electrode is made of titanium, chromium or titanium nitride. In the present invention, by preferably being close to the first electrode layer, titanium, chromium, and titanium nitride all grow into a columnar crystal structure during the preparation process, while molybdenum also has a columnar crystal structure, which belongs to the homoepitaxial growth type, and can effectively improve the diffusion barrier layer. The bonding force with the first electrode layer.

As a further preference, in the aforementioned stainless steel foil solar cell with a back protection layer, the back protection layer is made of titanium nitride, and the thickness of the back protection layer is 200nm; the layer close to the base is made of chromium, and the The middle layer is made of titanium nitride, the layer close to the first electrode is made of titanium, and the thickness of the diffusion barrier layer is 1200nm.

As a second object of the present invention, the present invention provides the aforementioned method for preparing a stainless steel foil solar cell with a back protection layer, comprising the following steps:

(1) Surface degreasing treatment and surface polishing treatment are carried out on the stainless steel foil substrate, so that the surface roughness of the stainless steel foil substrate reaches 1 nm to 2000 nm;

(2) Prepare a back protective layer on the opposite side of the solar energy receiving side of the stainless steel foil substrate, and the preparation method is selected from any of evaporation method, magnetron sputtering method, chemical vapor deposition method, electrochemical deposition method or chemical deposition method A sort of;

(3) preparing a diffusion barrier layer on the solar receiving side of the stainless steel foil substrate, the preparation method being selected from any one of chemical coating method, electrochemical coating method, chemical vapor deposition method, evaporation method or magnetron sputtering method;

(4) On the diffusion barrier layer, the first electrode layer, the absorption layer, the buffer layer, the second electrode layer, the antireflection layer and the surface electrode layer are sequentially prepared.

In the aforementioned stainless steel foil solar cell with a back protective layer, the preparation method of the first electrode layer is selected from any one of the evaporation method and the magnetron sputtering method. The thickness of the first electrode layer is 500nm-3000nm.

The aforementioned stainless steel foil solar cell with a back protection layer, wherein the absorbing layer can be selected from copper indium gallium selenide thin film, copper zinc tin sulfur thin film, copper indium sulfur thin film, cadmium telluride thin film, dye sensitive solar cell thin film and organic solar cell any kind of film. The preparation method of the absorption layer can be selected from any one of electrochemical deposition method, nanocrystalline particle coating method, evaporation method or magnetron sputtering method.

In the aforementioned stainless steel foil solar cell with a back protection layer, the buffer layer is selected from either zinc sulfide or cadmium sulfide. The preparation method of the buffer layer is selected from any one of solution method, chemical water bath method or magnetron sputtering method.

In the aforementioned stainless steel foil solar cell with a back protective layer, the material of the second electrode layer is selected from tin oxide doped with indium, tin oxide doped with fluorine, zinc oxide doped with aluminum, zinc oxide doped with boron or zinc oxide doped with gallium. The preparation method of the second electrode layer is selected from any one of magnetron sputtering method, reactive sputtering method and electron beam evaporation method.

In the aforementioned stainless steel foil solar cell with a back protective layer, the material of the antireflection layer is selected from any one of magnesium fluoride, titanium dioxide, silicon nitride, silicon dioxide, aluminum oxide, magnesium oxide or cerium oxide. The preparation method of the anti-reflection layer is selected from any one of evaporation method, sputtering method or chemical method.

In the aforementioned stainless steel foil solar cell with a back protection layer, the material of the surface electrode layer is selected from nickel, aluminum, silver and the like. The preparation method of the surface electrode layer is usually an evaporation method.

Compared with prior art, the beneficial effect of the present invention is:

1. The stainless steel foil solar cell with a back protective layer of the present invention forms a back protective layer on the opposite side of the solar receiving side of the stainless steel foil substrate, and screens the composition of the back protective layer, so that the obtained back protective layer can effectively avoid high temperature corrosion The damage to the stainless steel foil substrate in the process of non-toxic atmosphere can avoid decomposition and denaturation at high temperature, and will not bring more impurities to the stainless steel foil substrate, and the acquisition method is simple and the production cost is low.

2. The stainless steel foil solar cell with a back protective layer of the present invention forms a diffusion barrier layer on the solar receiving side, and preferably obtains the structure of the diffusion barrier layer and the components of each structure, and the obtained diffusion barrier layer can effectively block substrate impurities Elements enter the absorbing layer, and at the same time, can significantly increase the bonding force between the diffusion barrier layer and the substrate and the first electrode layer.

Description of drawings

Fig. 1 is the structural representation of stainless steel foil solar cell of the present invention;

Fig. 2 is the photo after the selenization of the stainless steel foil solar cell film that embodiment 1 makes;

Fig. 3, Fig. 4 are the binding force test photos of the stainless steel foil solar cell that embodiment 1 makes;

Fig. 5 is the EDS test result figure of the diffusion barrier layer of the solar cell that embodiment 1 makes;

Fig. 6 is a photo of the solar cell thin film obtained in the comparative test after selenization.

1-substrate, 2-back protection layer, 3-diffusion barrier layer, 4-first electrode layer, 5-absorption layer, 6-buffer layer, 7-second electrode layer, 8-anti-reflection layer, 9-surface electrode Layer, 301-close to the base layer, 302-intermediate layer, 303-close to the first electrode layer.

Detailed ways

The above content of the invention of the present invention will be further described in detail below in conjunction with specific embodiments.

However, it should not be construed that the scope of the above-mentioned subject matter of the present invention is limited to the following examples. Without departing from the above-mentioned technical idea of the present invention, various replacements and changes made according to common technical knowledge and customary means in this field shall be included in the scope of the present invention.

Example 1 This example is about a stainless steel foil solar cell and its preparation method.

Stainless steel foil solar cell, the structure is: the back protective layer 2 is titanium nitride, the thickness is 200nm; the substrate 1 is 430 stainless steel; the diffusion barrier layer 3 is a three-layer structure, the thickness is 1200nm, in which the layer 301 near the substrate is chromium, and the middle layer 302 is titanium nitride, and the first electrode layer 303 is titanium; the first electrode layer 4 is molybdenum; the absorption layer 5 is copper indium gallium selenide film; the buffer layer 6 is cadmium sulfide; the second electrode layer 7 is zinc oxide doped with aluminum ; The antireflection layer 8 is magnesium fluoride; the surface electrode layer 9 is nickel/aluminum/nickel.

Preparation:

(1) Treatment of stainless steel substrate: Polishing is carried out with a mixed solution of methanol and concentrated sulfuric acid, the volume ratio of methanol:concentrated sulfuric acid is 1:3, the polishing time is about 400s, and the voltage is about 10V.

(2) Preparation of the back protection layer 2: it is obtained by sputtering a titanium target with a thickness of 200 nm in a mixed gas of argon and nitrogen with a pressure of 4 mtorr and a power of 210 W by magnetron sputtering.

(3) Preparation of diffusion barrier layer 3:

Chromium near the base layer 301 : the magnetron sputtering method is prepared by sputtering a chromium target with a power of 240W in an argon gas pressure of 4mtorr, and the thickness is about 300nm.

The middle layer 302 is titanium nitride, which is obtained by sputtering a titanium target at a power of 210W in a mixed gas of argon and nitrogen at a pressure of 4mtorr by magnetron sputtering, with a thickness of about 600nm.

Titanium near the first electrode layer 303 is obtained by sputtering a titanium target at a power of 240 W under an argon gas pressure of 4 mtorr by magnetron sputtering, with a thickness of about 300 nm.

(4) The first electrode layer 4 is molybdenum: magnetron sputtering method, the gas pressure is 4mtorr of argon, the sputtering power is 210W, the sputtering target material is molybdenum target, and the thickness is about 1000nm.

(5) The absorption layer 5 is a copper indium gallium selenide thin film: the magnetron sputtering method is adopted, the pressure is 4mtorr of argon gas, the sputtering power is 120W, and the target material is a copper indium gallium selenide target material, and a prefabricated film with a thickness of about 800nm is obtained. membrane. After the thin film is prepared, in a fast selenization furnace, the absorbing layer thin film is selenized at a temperature of 600° C. to obtain a copper indium gallium selenide thin film.

(6) The buffer layer 6 is cadmium sulfide: prepared by chemical water bath method, the temperature of the water bath is 80° C., and the film thickness is about 60 nm.

(7) The second electrode layer 7 is zinc oxide doped with aluminum: Magnetron sputtering is used, the target material is zinc oxide doped with aluminum, the sputtering power is 180W, the temperature of the sample stage is 200°C, the air pressure is 4mtorr argon, and the thickness is about 500nm.

(8) The anti-reflection layer 8 is magnesium fluoride: resistive evaporation is adopted, the temperature is about 1300° C., and the thickness is about 80 nm.

(9) The surface electrode layer 9 is nickel/aluminum/nickel: the nickel film adopts the electron beam evaporation method, and the thickness of the first layer of nickel film is about 200nm to prevent the diffusion of aluminum, and the thickness of the second layer of nickel film is about 200nm to prevent For the oxidation of aluminum, the aluminum thin film in the middle layer adopts the method of resistive evaporation, and the thickness is about 3000nm.

The obtained stainless steel foil solar cell is selenized at high temperature, as shown in Figure 2, and the film does not fall off. The manufactured stainless steel foil solar cell device is tested, and the film will not fall off even after being bent.

The prepared stainless steel foil solar cell was tested for the bonding force between the back protective layer 2 and the substrate 1, and the diffusion isolation layer 3 and the substrate 1 respectively, using the adhesive tape method, using 3M adhesive tape, as shown in Figure 3 and Figure 4, after tearing , the film did not fall off, indicating that the film adhesion is very good.

The prepared stainless steel foil solar cell, the EDS test result is shown in Figure 5, and the EDS test data is shown in Table 1:

Table 1. EDS test data

From the data in Figure 5 and Table 1, it can be seen that the diffusion barrier layer 3 of the stainless steel foil solar cell has a good barrier effect, and no impurity elements in the molybdenum foil enter the absorber layer 5 .

As a comparative test, the same preparation method was used to prepare stainless steel foil solar cells, in which the diffusion barrier layer was two layers, which were prepared from Cr and TiNx respectively. The effect of bonding force after high temperature selenization is shown in Figure 6, and the film falls off when subjected to external force.

Embodiment 2 This embodiment is a stainless steel foil solar cell and its preparation method

Stainless steel foil solar cell, the structure is: the back protective layer 2 is silicon carbide with a thickness of 200nm; the substrate 1 is 430 stainless steel; the diffusion barrier layer 3 is a three-layer structure with a thickness of 1200nm, in which the layer 301 near the substrate is chromium, and the middle layer 302 SiC, close to the first electrode layer 303 is chromium; the first electrode layer 4 is molybdenum; the absorption layer 5 is copper indium gallium selenide film; the buffer layer 6 is cadmium sulfide; the second electrode layer 7 is zinc oxide doped with aluminum; The anti-layer 8 is magnesium fluoride; the surface electrode layer 9 is nickel/aluminum/nickel.

Preparation:

(1) Treatment of stainless steel substrate: Polishing is carried out with a mixed solution of methanol and concentrated sulfuric acid, the volume ratio of methanol:concentrated sulfuric acid is 1:3, the polishing time is about 400s, and the voltage is about 10V.

(2) Preparation of the back protection layer 2 : it is obtained by sputtering a silicon carbide target at a power of 210 W in an argon gas pressure of 4 mtorr by a magnetron sputtering method, with a thickness of 200 nm.

(3) Preparation of diffusion barrier layer 3:

Chromium near the base layer 301 : the magnetron sputtering method is prepared by sputtering a chromium target with a power of 240W in an argon gas pressure of 4mtorr, and the thickness is about 300nm.

The middle layer 302 is silicon carbide, which is obtained by sputtering a silicon carbide target with a power of 210 W in an argon gas with a pressure of 4 mtorr and a thickness of about 600 nm by magnetron sputtering.

Chromium near the first electrode layer 303 is obtained by sputtering a chromium target with a magnetron sputtering method under an argon gas pressure of 4 mtorr and a power of 240 W, with a thickness of about 300 nm.

(4) The first electrode layer 4 is molybdenum: magnetron sputtering method, the gas pressure is 4mtorr of argon, the sputtering power is 210W, the sputtering target material is molybdenum target, and the thickness is about 1000nm.

(5) The absorption layer 5 is a copper indium gallium selenide thin film: the magnetron sputtering method is adopted, the pressure is 4mtorr of argon gas, the sputtering power is 120W, and the target material is a copper indium gallium selenide target material, and a prefabricated film with a thickness of about 800nm is obtained. membrane. After the thin film is prepared, in a fast selenization furnace, the absorbing layer thin film is selenized at a temperature of 600° C. to obtain a copper indium gallium selenide thin film.

(6) The buffer layer 6 is cadmium sulfide: prepared by chemical water bath method, the temperature of the water bath is 80° C., and the film thickness is about 60 nm.

(7) The second electrode layer 7 is zinc oxide doped with aluminum: Magnetron sputtering is used, the target material is zinc oxide doped with aluminum, the sputtering power is 180W, the temperature of the sample stage is 200°C, the air pressure is 4mtorr argon, and the thickness is about 500nm.

(8) The anti-reflection layer 8 is magnesium fluoride: resistive evaporation is adopted, the temperature is about 1300° C., and the thickness is about 80 nm.

(9) The surface electrode layer 9 is nickel/aluminum/nickel: the nickel film adopts the electron beam evaporation method, and the thickness of the first layer of nickel film is about 200nm to prevent the diffusion of aluminum, and the thickness of the second layer of nickel film is about 200nm to prevent For the oxidation of aluminum, the aluminum thin film in the middle layer adopts the method of resistive evaporation, and the thickness is about 3000nm.

Embodiment 3 This embodiment is a stainless steel foil solar cell

Stainless steel foil solar cell structure: the back protective layer 2 is tantalum nitride with a thickness of 200nm; the substrate 1 is 430 stainless steel; the diffusion barrier layer 3 is a three-layer structure, the diffusion barrier layer 3 near the base layer 301 is titanium, and the middle layer 302 is Tantalum nitride, near the first electrode layer 303 is titanium nitride, the thickness of the diffusion barrier layer 3 is 3000nm; the first electrode layer 4 is molybdenum; the absorption layer 5 is copper indium gallium selenide thin film; the buffer layer 6 is cadmium sulfide; The electrode layer 7 is zinc oxide doped with aluminum; the antireflection layer 8 is magnesium fluoride; the surface electrode layer 9 is nickel/aluminum/nickel.

Embodiment 4 This embodiment is a stainless steel foil solar cell

Stainless steel foil solar cell structure: the back protection layer 2 is made of titanium with a thickness of 200nm; the substrate 1 is made of 430 stainless steel; the diffusion barrier layer 3 has a three-layer structure, the layer 301 near the base of the diffusion barrier layer 3 is made of tantalum nitride, and the middle layer 302 is Titanium nitride, near the first electrode layer 303 is titanium, the thickness of the diffusion barrier layer 3 is 2000nm; the first electrode layer 4 is molybdenum; the absorption layer 5 is copper indium gallium selenide thin film; the buffer layer 6 is cadmium sulfide; the second electrode layer 7 is zinc oxide mixed with aluminum; the anti-reflection layer 8 is magnesium fluoride; the surface electrode layer 9 is nickel/aluminum/nickel.

Embodiment 5 This embodiment is a stainless steel foil solar cell

Stainless steel foil solar cell structure: the back protection layer 2 is titanium with a thickness of 200nm; the substrate 1 is 430 stainless steel; the diffusion barrier layer 3 is a four-layer structure, and the diffusion barrier layer 3 near the base layer 301 is two layers, including titanium layer and chromium layer, the middle layer 302 is tantalum nitride, the first electrode layer 303 is titanium nitride, the thickness of the diffusion barrier layer 3 is 3000nm; the first electrode layer 4 is molybdenum; the absorption layer 5 is copper indium gallium selenide film; buffer layer 6 is cadmium sulfide; the second electrode layer 7 is zinc oxide doped with aluminum; the antireflection layer 8 is magnesium fluoride; the surface electrode layer 9 is nickel/aluminum/nickel.

Claims (9)

1. there is the stainless steel foil solar cell of back of the body protective layer; the diffusion impervious layer comprising stainless steel foil substrate and formed successively in stainless steel foil substrate, the first electrode layer, absorbed layer, resilient coating, the second electrode lay, anti-reflection layer and surface electrode layer, is characterized in that:

The opposite side of the solar energy receiver side of described stainless steel foil substrate is formed with back of the body protective layer, and described back of the body protective layer is individual layer, and described back of the body protective layer is optionally made by following group:

A group: aluminium, molybdenum, titanium, nickel, copper, zirconium, niobium, chromium, ruthenium, rhodium, palladium, tantalum, tungsten, iridium, osmium, platinum, gold or silver-colored, or their alloy; Or

B group: the nitride of silicon, oxide or carbide; Or

C group: titanium nitride, tantalum nitride, tungsten nitride or zirconium nitride;

Described back of the body protective layer thickness is 10nm ~ 3000nm;

Described diffusion impervious layer is more than three layers or three layers structures, and every one deck of described diffusion impervious layer is optionally made by following group:

A group: aluminium, molybdenum, titanium, nickel, copper, zirconium, niobium, chromium, ruthenium, rhodium, palladium, tantalum, tungsten, iridium, osmium, platinum, gold or silver-colored, or their alloy; Or

B group: the nitride of silicon, oxide or carbide; Or

C group: titanium nitride, tantalum nitride, tungsten nitride or zirconium nitride;

The thickness of described diffusion impervious layer is 10nm ~ 3000nm.

2. the stainless steel foil solar cell with back of the body protective layer according to claim 1, it is characterized in that, described first electrode layer is molybdenum film layer.

3. the stainless steel foil solar cell with back of the body protective layer according to claim 1, it is characterized in that, described back of the body protective layer is made up of silicon nitride, silica, carborundum, titanium nitride, tantalum nitride, tungsten nitride or zirconium nitride.

4. the stainless steel foil solar cell with back of the body protective layer according to any one of claims 1 to 3, it is characterized in that, described diffusion impervious layer is three-decker, comprises near basalis, intermediate layer and close first electrode layer.

5. the stainless steel foil solar cell with back of the body protective layer according to claim 4, is characterized in that, the intermediate layer of described diffusion impervious layer is made up of any one of titanium nitride, tantalum nitride, tungsten nitride or zirconium nitride.

6. the stainless steel foil solar cell with back of the body protective layer according to claim 4, it is characterized in that, the close basalis of described diffusion impervious layer is made up of titanium, chromium, titanium nitride or tantalum nitride.

7. the stainless steel foil solar cell with back of the body protective layer according to claim 4, is characterized in that, being made up of titanium, chromium or titanium nitride near the first electrode layer of described diffusion impervious layer.

8. the stainless steel foil solar cell with back of the body protective layer according to claim 4, it is characterized in that, described back of the body protective layer is made up of titanium nitride, and described back of the body protective layer thickness is 200nm; Described close basalis is made up of chromium, and described intermediate layer is made up of titanium nitride, and described close first electrode layer is made of titanium, and the thickness of described diffusion impervious layer is 1200nm.

9. the preparation method with the stainless steel foil solar cell of back of the body protective layer described in any one of claim 1 ~ 8, is characterized in that, comprise the steps:

(1) surface degreasing process and surface finish process are carried out in stainless steel foil substrate, make described stainless steel foil substrate surface roughness reach 1nm ~ 2000nm;

(2) at the opposite side preparation back of the body protective layer of the solar energy receiver side of stainless steel foil substrate, described preparation method is selected from any one of vapour deposition method, magnetron sputtering method, chemical vapour deposition technique, electrochemical deposition method or chemical deposition;

(3) prepare diffusion impervious layer at the solar energy receiver side of stainless steel foil substrate, described preparation method is selected from any one of electroless plating, electrochemical filming method, chemical vapour deposition technique, vapour deposition method or magnetron sputtering method;

(4) the first electrode layer, absorbed layer, resilient coating, the second electrode lay, anti-reflection layer and surface electrode layer is prepared successively on the diffusion barrier.