A CdTe battery and its preparation method

Abstract

The present invention relates to a CdTe battery and a preparation method thereof, belonging to the technical field of solar cells. The CdTe battery includes a power generation glass structure, and the power generation glass structure includes a float glass layer, a composite transparent conductive layer, a power generation layer, a back contact buffer layer, and a composite back electrode layer; the composite transparent conductive layer includes a first metal compound layer, a first metal layer, and a second metal compound layer, and both the first metal compound layer and the second metal compound layer are metal oxide layers or metal sulfide layers; the composite back electrode layer includes a metal nitride layer, a second metal layer, and a third metal layer. On the basis of the existing CdTe battery structure, the present invention uses a composite transparent conductive layer with a specific structure as the front electrode, and cooperates with a composite back electrode layer with a specific structure. By matching the film thickness and refractive index of each layer, the light transmittance and conductivity of the overall film layer are improved, and at the same time, the cost is reduced, making up for the deficiencies of the existing CdTe battery.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and particularly to a CdTe cell and a preparation method thereof. Background Art

[0002] Cadmium telluride (CdTe) power generation glass is an "all-in-one", green, energy-saving and energy-generating building material. It is made by covering ordinary glass with cadmium telluride optoelectronic materials. This material can turn ordinary glass from an insulator into a solar cell capable of generating electricity. Theoretically, compared with crystalline silicon cells, CdTe cells have advantages such as good low-light performance, high power generation, good high-temperature adaptability, short energy payback period, and wide application range. For example, it can generate electricity in low-light environments or under scattered light, cloudy, rainy weather conditions. In addition, cadmium telluride power generation glass can be made into different light transmittances as needed to replace glass curtain walls. It not only has a beautiful appearance and can generate electricity, but also can effectively block external infrared rays from entering and internal heat energy from dissipating. It has unparalleled potential and superiority in the application of building integrated photovoltaics projects compared with crystalline silicon cells.

[0003] However, crystalline silicon cells started earlier, have mature technologies and high market shares. In the actual mass production process, there is still a large gap between the photoelectric conversion efficiency and production cost of CdTe cells and the theoretical values, and technical personnel in the industry need to continuously explore new technologies and optimize production processes.

[0004] At present, on the one hand, CdTe cells generally use precious metals such as molybdenum or nickel as raw materials for the back electrode, which are relatively expensive and have high energy consumption during the manufacturing process; on the other hand, CdTe cells generally use a single transparent conductive oxide (TCO) thin film as the front electrode. Due to the mutually exclusive properties of light transmittance and conductivity, it is impossible to improve both light transmittance and conductivity simultaneously. Summary of the Invention

[0005] To solve the above problems, the present invention provides a CdTe cell and a preparation method thereof.

[0006] In a first aspect, the present invention provides a CdTe cell, the CdTe cell includes a power generation glass structure, and the power generation glass structure includes a float glass layer, a composite transparent conductive layer, a power generation layer, a back contact buffer layer, and a composite back electrode layer;

[0007] The composite transparent conductive layer includes a first metal compound layer, a first metal layer, and a second metal compound layer, and both the first metal compound layer and the second metal compound layer are metal oxide layers or metal sulfide layers;

[0008] The composite back electrode layer includes a metal nitride layer, a second metal layer, and a third metal layer.

[0009] Further, both the first metal compound layer and the second metal compound layer are FTO layers or ZnS layers, and the first metal layer is an Ag layer.

[0010] Further, the metal nitride layer is a molybdenum nitride layer, the second metal layer is an aluminum layer, and the third metal layer is a chromium layer or a nickel layer.

[0011] Further, the material of the power generation layer is CdS / CdTe or CdSe x Te 1-x , where X is 0.025 - 0.04; the material of the back contact buffer layer is ZnTe:AgyCu1-y.

[0012] Further, a barrier layer is provided between the float glass layer and the first metal compound layer, a high-resistance layer is provided between the second metal compound layer and the power generation layer, and the back contact buffer layer is in contact with the metal nitride layer; wherein, the barrier layer is SiOx with a thickness of 20 nm; the high-resistance layer is SnO2 with a thickness of 35 nm.

[0013] Further, the CdTe cell sequentially includes an AR-coated tempered glass, a first PVB film + butyl rubber edge sealing layer, the power generation glass structure, a lead bus bar, a second PVB film + butyl rubber edge sealing layer, and a tempered glass from the light-receiving surface upwards.

[0014] Further, the AR-coated tempered glass is a tempered glass coated with an AR antireflection film coating, and the light transmittance of the AR-coated tempered glass > 93%, with a thickness of 3.2 mm;

[0015] The PVB film of the first PVB film + butyl rubber edge sealing layer bonds the AR-coated tempered glass and the float glass layer into one body, and the edge is sealed with butyl rubber; the thickness of the PVB film in the first PVB film + butyl rubber edge sealing layer is 0.76 mm, the width of the butyl rubber is 10 - 12 mm, and the thickness is 0.5 mm;

[0016] The light transmittance of the float glass layer > 93%, with a thickness of 3.2 mm;

[0017] The thickness of the composite transparent conductive layer is 60 - 100 nm;

[0018] The thickness of the power generation layer is 3 - 5 μm;

[0019] The thickness of the back contact buffer layer is 18 - 43 nm;

[0020] The thickness of the composite back electrode layer is 300 - 500 nm;

[0021] The lead busbar is bonded to the composite back electrode layers on both sides, and the current is led out through the holes in the tempered glass. The width of the lead busbar is 6.4 mm;

[0022] The PVB film of the second PVB film + butyl rubber edge sealing layer bonds the power generation glass structure and the tempered glass into one body, and the edge is sealed with butyl rubber; the thickness of the PVB film in the second PVB film + butyl rubber edge sealing layer is 0.76 mm, the width of the butyl rubber is 10 - 12 mm, and the thickness is 0.5 mm;

[0023] The thickness of the tempered glass is 3.2 mm.

[0024] In a second aspect, the present invention provides a method for preparing a CdTe cell according to any one of the first aspect, and the preparation method includes the following steps:

[0025] Use a PVB film to bond the AR-coated tempered glass and the float glass layer into one body, and the edge is sealed with butyl rubber;

[0026] Grow film layers of different materials on the float glass layer in sequence to form the power generation glass structure;

[0027] Use a PVB film to bond the power generation glass structure and the tempered glass into one body, and the edge is sealed with butyl rubber to obtain the CdTe cell;

[0028] The method for growing film layers of different materials on the float glass layer in sequence includes at least one of magnetron sputtering, chemical vapor deposition, and close-spaced sublimation.

[0029] The above technical solutions provided by the embodiments of the present invention have at least the following advantages compared with the prior art:

[0030] The embodiments of the present invention provide a CdTe cell. On the basis of the structure of the existing CdTe cell, the present invention uses a composite transparent conductive layer with a specific structure as the front electrode, and cooperates with a composite back electrode layer with a specific structure. By matching the film thickness and refractive index of each layer, the light transmittance and conductivity of the overall film layer are improved, and the cost is reduced at the same time, making up for the deficiencies of the existing CdTe cell. Specifically:

[0031] 1) For the front electrode, the prior art usually uses a single-layer transparent conductive layer, which is one of FTO, ITO, AZO, or other doped metal oxides; what this patent uses is a multi-layer composite conductive layer, which is a composite structure stacked by metals and metal oxides (or sulfides), such as Figure 2As shown; by using a multi-layer composite transparent conductive film layer instead of a single-layer transparent conductive film layer, the overall film layer thickness is greatly reduced, reducing the overall production and manufacturing cost. At the same time, the light transmittance of the conductive film layer is improved, the sheet resistance is reduced, and the performance of the CdTe battery is enhanced.

[0032] 2) For the back electrode, the prior art usually uses a single conductive layer, which is one of Mo, Ni or other metals; the back electrode used in this patent is a multi-layer composite conductive layer, which is a composite structure stacked by a metal and a metal nitride, such as Figure 3 As shown; by using a multi-layer composite back electrode film layer instead of a single-layer back electrode film layer, the cost of raw materials is reduced, the sheet resistance of the back electrode is reduced, and the performance of the CdTe battery is enhanced.

[0033] 3) Compared with the prior art, the main difference in the preparation process of this patent is that: in the prior art, a film layer of the same material is grown on the substrate by chemical vapor deposition or magnetron sputtering once or multiple times to finally form a single-layer structure; in this patent, film layers of different materials are sequentially grown on the substrate by chemical vapor deposition and / or magnetron sputtering to finally form a multi-layer stacked composite structure. Description of the Drawings

[0034] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative labor.

[0036] Figure 1 It is a flowchart of the preparation method of the CdTe battery provided by the embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of the composite transparent conductive layer in the CdTe battery provided by the embodiment of the present invention;

[0038] Figure 3 It is a schematic diagram of the composite back electrode layer in the CdTe battery provided by the embodiment of the present invention;

[0039] Figure 4 It is a schematic diagram of the power generation glass structure in the CdTe battery provided by the embodiment of the present invention;

[0040] Figure 5 It is a comparison chart of the transmittance of different front electrodes of the CdTe battery in the test example of the present invention.

[0041] Figure 6This is the comparison test result graph of the sheet resistance of different transparent electrodes in the test examples of the present invention.

[0042] Figure 7 This is the comparison test result graph of the sheet resistance of different back electrodes in the test examples of the present invention. Detailed implementation manners

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments and equipment used in the present invention can be obtained through market purchase or can be prepared by existing methods.

[0045] In a first aspect, the present invention provides a CdTe battery, and the CdTe battery includes a power generation glass structure, as Figure 4 shown, the power generation glass structure includes a float glass layer, a composite transparent conductive layer, a power generation layer, a back contact buffer layer and a composite back electrode layer;

[0046] The composite transparent conductive layer includes a first metal compound layer, a first metal layer and a second metal compound layer, and both the first metal compound layer and the second metal compound layer are metal oxide layers or metal sulfide layers;

[0047] The composite back electrode layer includes a metal nitride layer, a second metal layer and a third metal layer.

[0048] The embodiments of the present invention provide a CdTe battery. Based on the structure of the existing CdTe battery, the present invention uses a composite transparent conductive layer with a specific structure as the front electrode, and cooperates with a composite back electrode layer with a specific structure. By matching the film thickness and refractive index of each layer, the light transmittance and conductivity of the overall film layer are improved, and the cost is reduced at the same time, making up for the deficiencies of the existing CdTe battery. Specifically:

[0049] 1) For the front electrode, the prior art usually uses a single-layer transparent conductive layer, which is one of FTO, ITO, AZO or other doped metal oxides; what this patent uses is a multi-layer composite conductive layer, which is a composite structure stacked by metals and metal oxides (or sulfides), as Figure 2As shown; by using a multi-layer composite transparent conductive film layer instead of a single-layer transparent conductive film layer, the overall film layer thickness is greatly reduced, reducing the overall production and manufacturing cost. At the same time, the light transmittance of the conductive film layer is improved, the sheet resistance is reduced, and the performance of the CdTe battery is enhanced.

[0050] 2) For the back electrode, the prior art usually uses a single conductive layer, which is one of Mo, Ni or other metals; the present patent uses a multi-layer composite conductive layer, which is a composite structure stacked by a metal and a metal nitride, such as Figure 3 As shown; by using a multi-layer composite back electrode film layer instead of a single-layer back electrode film layer, the cost of raw materials is reduced, the sheet resistance of the back electrode is reduced, and the performance of the CdTe battery is enhanced.

[0051] 3) Compared with the prior art, the main difference in the preparation process of the present patent is that: in the prior art, a film layer of the same material is grown on the substrate by chemical vapor deposition or magnetron sputtering once or multiple times to finally form a single-layer structure; in the present patent, film layers of different materials are sequentially grown on the substrate by chemical vapor deposition and / or magnetron sputtering to finally form a multi-layer stacked composite structure.

[0052] In some specific embodiments, both the first metal compound layer and the second metal compound layer are FTO layers or ZnS layers, and the first metal layer is an Ag layer.

[0053] In some specific embodiments, the metal nitride layer is a molybdenum nitride layer, the second metal layer is an aluminum layer, and the third metal layer is a chromium layer or a nickel layer.

[0054] In some specific embodiments, the material of the power generation layer is CdS / CdTe or CdSe x Te 1-x , where X is 0.025 - 0.04; the material of the back contact buffer layer is ZnTe:AgyCu1-y. In the present invention, ZnTe:AgyCu1-y is doped with Ag and Cu in a certain stoichiometric ratio to the main material ZnTe, and the value of y is 0.5 - 0.8.

[0055] In some specific embodiments, a barrier layer is provided between the float glass layer and the first metal compound layer, a high-resistance layer is provided between the second metal compound layer and the power generation layer, and the back contact buffer layer is in contact with the metal nitride layer; wherein, the barrier layer is SiOx with a thickness of 20 nm; the high-resistance layer is SnO2 with a thickness of 35 nm.

[0056] In some specific embodiments, the CdTe cell sequentially includes, from the light-receiving surface upwards, an AR-coated tempered glass, a first PVB film + butyl rubber edge sealing layer, the power generation glass structure, a current collecting bus bar, a second PVB film + butyl rubber edge sealing layer, and a tempered glass.

[0057] In some specific embodiments, the AR-coated tempered glass is a tempered glass with an AR anti-reflection film coating on its surface. The light transmittance of the AR-coated tempered glass is > 93%, and the thickness is 3.2 mm. The AR anti-reflection film coating is a high-temperature sintered and cured AR anti-reflection film coating. The raw materials of the AR anti-reflection film and the tempered glass are directly commercially available products. In this patent, the anti-reflection film coating is prepared on the tempered glass by the doctor blade method, and then sintered and cured at a high temperature of about 200 degrees.

[0058] The PVB film of the first PVB film + butyl rubber edge sealing layer bonds the AR-coated tempered glass and the float glass layer together, and the butyl rubber seals the edge. The thickness of the PVB film in the first PVB film + butyl rubber edge sealing layer is 0.76 mm, the width of the butyl rubber is 10 - 12 mm, and the thickness is 0.5 mm.

[0059] The light transmittance of the float glass layer is > 93%, and the thickness is 3.2 mm.

[0060] The thickness of the composite transparent conductive layer is 60 - 100 nm.

[0061] The thickness of the power generation layer is 3 - 5 μm.

[0062] The thickness of the back contact buffer layer is 18 - 43 nm.

[0063] The thickness of the composite back electrode layer is 300 - 500 nm.

[0064] The current collecting bus bar is bonded to the two sides of the composite back electrode layer, and leads the current out through the holes in the tempered glass. The width of the current collecting bus bar is 6.4 mm.

[0065] The PVB film of the second PVB film + butyl rubber edge sealing layer bonds the power generation glass structure and the tempered glass together, and the butyl rubber seals the edge. The thickness of the PVB film in the second PVB film + butyl rubber edge sealing layer is 0.76 mm, the width of the butyl rubber is 10 - 12 mm, and the thickness is 0.5 mm.

[0066] The thickness of the tempered glass is 3.2 mm.

[0067] It should be noted that for the component raw materials involved in the CdTe cell provided in the embodiments of the present invention, unless otherwise specifically limited or described, commercially available products can be directly used.

[0068] In a second aspect, based on a general inventive concept, the present invention provides a method for preparing a CdTe cell according to any one of the first aspect, the preparation method comprising the following steps:

[0069] Bond the AR-coated tempered glass and the float glass layer together using a PVB film, and seal the edges with butyl rubber;

[0070] Grow film layers of different materials on the float glass layer in sequence to form the power generation glass structure;

[0071] Bond the power generation glass structure and the tempered glass together using a PVB film, and seal the edges with butyl rubber to obtain the CdTe cell;

[0072] The method for growing film layers of different materials on the float glass layer includes at least one of magnetron sputtering, chemical vapor deposition, and close space sublimation.

[0073] In some specific embodiments, the preparation method of the above CdTe cell includes the following process:

[0074] Provide a CdTe cell based on a low-cost composite electrode and a preparation method thereof. The battery structure adopted in this patent is a sandwich structure, which from the light-receiving surface upwards is: AR-coated tempered glass, a first PVB film + butyl rubber edge sealing layer, ultra-clear float glass, a multi-layer composite transparent conductive layer, a power generation layer (CdS / CdTe or CdSe x Te 1-x ), a back contact buffer layer, a multi-layer composite back electrode layer, a lead bus bar, a second PVB film + butyl rubber edge sealing layer, and tempered glass; wherein the ultra-clear float glass, the multi-layer composite transparent conductive layer, the power generation layer (CdS / CdTe or CdSe x Te 1-x ), the back contact buffer layer, and the multi-layer composite back electrode layer are stacked in sequence and then formed into a structure in which a number of sub-cells are connected in series after laser scribing, which is called power generation glass, such as Figure 4 .

[0075] For the AR-coated tempered glass, its surface is coated with a high-temperature sintered and cured AR anti-reflection film coating, and its light transmittance is above 93%;

[0076] The PVB film of the first PVB film + butyl rubber edge sealing layer bonds the AR-coated tempered glass and the ultra-clear float glass together; PVB can use high-transmittance PVB with a relatively high light transmittance, or other colored PVB films can also be selected; the thickness of the PVB film is 0.76 mm; the butyl rubber edge seal mainly plays a role in edge waterproofing and improves the service life;

[0077] The super-white float glass has a light transmittance of more than 93%;

[0078] The usual transparent conductive layer (TCO) is a single layer of FTO, AZO or ITO with a thickness of 300 - 400 nm. The multi-layer composite transparent conductive layer described in this patent is a three-layer structure of FTO / Ag / FTO or ZnS / Ag / ZnS, such as Figure 2 . The resistivity of Ag is much smaller than that of FTO and ZnS. Therefore, the sheet resistance of the three-layer composite transparent conductive film layer is mainly determined by the metal Ag. Compared with using only TCO as the electrode, the metal layer of the composite transparent electrode provides high lateral conductivity. Therefore, the other two layers usually do not need to have high conductivity. So the FTO and ZnS layers can be significantly thinned without significantly affecting the sheet resistance of the composite film layer. Compared with the single layer of FTO, AZO or ITO, the multi-layer composite transparent conductive layer has a higher light transmittance and a lower resistivity. The thickness of Ag in the three-layer structure needs to be precisely controlled. If it is too thin, the prepared film layer is not continuous enough, increasing the scattering of visible light in it. If it is too thick, the absorption and reflection of visible light increase, reducing the transmittance. This patent preferably uses magnetron sputtering to prepare the Ag layer, with a base vacuum of the order of 10^-6 and a sputtering pressure of the order of 10^-3, which can prepare a continuous and ultra-thin Ag layer. The thickness and refractive index of the FTO and ZnS layers need to match the thickness of the Ag layer. Otherwise, due to the interference of light in the multi-layer structure, the overall transmittance of the multi-layer electrode will be reduced. The FTO and ZnS layers can be prepared by chemical vapor deposition or magnetron sputtering. This patent uses an integrated magnetron sputtering device to prepare the three-layer structure, which has a total of three independent process chambers, and there is at least one vacuum chamber between adjacent process chambers. The glass substrate continuously enters the magnetron sputtering device, with a sheet flow rate of 1.8 m / min, and the process gas is argon. FTO / Ag / FTO or ZnS / Ag / ZnS are sequentially deposited on the glass substrate to finally form a three-layer composite transparent conductive film layer;

[0079] The material of the light-emitting layer is CdS / CdTe or CdSe x Te 1-x , the thickness of CdS / CdTe is about 3 - 5 μm; CdSe x Te 1-x has a thickness of 3 - 5 μm, where X is 0.025 - 0.04;

[0080] The material of the back contact layer is ZnTe:AgyCu1-y, and the total thickness of the composite film layer is about 18 - 43 nm.

[0081] The first channel P1 laser scribing uses a laser with a wavelength of 355 nm; the transparent conductive layer / light-emitting layer / back contact layer is cut into equally wide sub-long strip shapes with a width of 5 - 10 mm. Insulating glue is filled in the first channel P1 through lithography technology;

[0082] The second channel P2 laser scribing uses a laser with a wavelength of 532 nm to cut the power generation layer / back contact layer into equally wide sub-long strips with a width of 5-10 mm at intervals of 60-90 μm based on P1.

[0083] The back electrode layer is a conductive thin film composed of a molybdenum nitride / aluminum / chromium or molybdenum nitride / aluminum / nickel triple-layer composite, such as Figure 3 , with a total thickness of about 300-500 nm, filling the second channel and being in series with the transparent conductive layer. Molybdenum nitride has a higher work function than metallic molybdenum, which can reduce the Schottky barrier with the CdTe layer or the back contact layer. The substitution of aluminum / chromium / nickel for molybdenum reduces the raw material cost, and aluminum has better conductivity, providing high lateral conductivity for the composite back electrode and increasing the transmission current of the CdTe cell. Chromium / nickel has strong antioxidant properties and, as the outermost layer, isolates air oxidation and enhances the stability of the CdTe cell. Molybdenum nitride / aluminum / chromium / nickel are all prepared using an integrated magnetron sputtering device, which has a total of three independent process chambers, and there is at least one vacuum chamber between adjacent process chambers. The glass substrate continuously enters the magnetron sputtering device, and the wafer flow rate is 1.8 m / min. Molybdenum nitride / aluminum / chromium or molybdenum nitride / aluminum / nickel are sequentially deposited on the glass substrate to finally form a triple-layer composite conductive film layer. The process gas for molybdenum nitride is a mixed gas of nitrogen and argon, and the flow ratio is 3:7 to 5:5. The process gases for aluminum / chromium / nickel are all argon.

[0084] The third channel P3 laser scribing uses a laser with a wavelength of 532 nm to cut the power generation layer / back contact layer / back electrode layer into equally wide sub-long strips with a width of 5-10 mm at intervals of 60-90 μm based on P2.

[0085] The fourth channel P4 is to remove the four sides of the power generation glass by laser or mechanically, and the edge cleaning width is 9-10 mm. On the one hand, it provides an insulating substrate for butyl rubber coating, and on the other hand, it ensures the isolation of the power generation area of the power generation glass from the external environment and prevents pollution of the power generation area.

[0086] The lead busbars are sequentially bonded to the back electrode layers on both sides to lead out the current through the holes in the tempered glass.

[0087] The second PVB film + butyl rubber edge sealing layer, the butyl rubber edge sealing mainly plays a role in edge waterproofing, and the main role of PVB is to bond the power generation glass and the tempered glass into one body; the width of the butyl rubber is 10 mm - 12 mm, the thickness is 0.5 mm, and the thickness of the PVB film is 0.76 mm; the tempered glass protects the middle power generation glass.

[0088] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. For the experimental methods without specific conditions in the following embodiments, they are usually determined according to national standards. If there is no corresponding national standard, they are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0089] Example 1

[0090] This example provides a CdTe cell, specifically a CdTe cell with a front electrode of FTO / Ag / FTO and a back electrode of molybdenum nitride / aluminum / chromium. Its preparation method includes the following steps:

[0091] For the AR-coated tempered glass, an AR anti-reflection film coating cured by high-temperature sintering is coated on its surface, and its light transmittance is above 93%;

[0092] The PVB film of the first PVB film + butyl rubber edge sealing layer bonds the AR-coated tempered glass and the ultra-clear float glass into one body; PVB can use high-transmittance PVB with a higher light transmittance, or other colored PVB films can also be selected; the thickness of the PVB film is 0.76 mm; the butyl rubber edge sealing mainly plays a role in edge waterproofing and improves the service life.

[0093] The light transmittance of the ultra-clear float glass is above 93%.

[0094] On the float glass, a barrier layer SiO x is prepared by chemical vapor deposition, and the thickness is 20 nm.

[0095] On the float glass with a barrier layer, an FTO / Ag / FTO layer is sequentially prepared by magnetron sputtering. The base vacuum is of the order of 10 to the -6th power, the sputtering pressure is of the order of 10 to the -3rd power, the flow rate of the process gas is 500 sccm, the wafer flow rate is 1.8 m / min, and the process gas is argon. The thickness of each layer is 31.25 / 9.05 / 35.31 nm respectively, and the total thickness is about 76 nm. As a comparison, the FTO layer is grown three times by magnetron sputtering, and the thickness of each layer is 32.79 / 177.26 / 177.48 nm respectively, and finally a single-layer FTO layer is formed, with a total thickness of about 388 nm;

[0096] On the FTO / Ag / FTO triple layer or the FTO single layer, a high-resistance layer SnO2 is prepared by chemical vapor deposition, and the thickness is 35 nm.

[0097] The material of the power generation layer is CdSe x Te 1-x , with a thickness of 3.1 μm, where X is 0.03, and it is prepared above the transparent conductive layer.

[0098] The material of the back contact layer is ZnTe:AgyCu1-y, where y is 0.6; the total thickness of the composite film layer is about 41 nm, and it is prepared above the power generation layer.

[0099] The first channel P1 laser scribing uses a laser with a wavelength of 355 nm; the transparent conductive layer / power generation layer / back contact layer is cut into equally wide sub-long strips with a width of 7.2 mm. Insulating glue is filled in the first channel P1 through photolithography technology.

[0100] The second channel P2 laser scribing uses a laser with a wavelength of 532 nm, and the power generation layer / back contact layer is cut into equally wide sub-long strips with a width of 7.2 mm at an interval of 90 μm based on P1.

[0101] A molybdenum nitride / aluminum / chromium layer is sequentially prepared on the back contact layer by magnetron sputtering. The base vacuum is on the order of 10 to the -6th power, the sputtering pressure is on the order of 10 to the -3rd power, the wafer flow rate is 1.8 m / min. The process gas for molybdenum nitride (MoNx) is a mixed gas of nitrogen and argon, with a flow ratio of 3:7 and a total flow rate of 600 sccm. The process gases for aluminum (Al) and chromium (Cr) are both argon, with flow rates of 600 sccm each. The thickness of each layer is 34.65 / 182.17 / 91.03 nm respectively, and the total thickness is about 307 nm. For comparison, a molybdenum (Mo) layer is grown in three times by magnetron sputtering, with each layer thickness of 34.52 / 182.74 / 181.98 nm respectively, and finally a single-layer Mo layer is formed with a total thickness of about 400 nm. For the specific performance parameter comparison, please refer to the table and the attached drawings.

[0102] The third channel P3 laser scribing uses a laser with a wavelength of 532 nm, and the power generation layer / back contact layer / back electrode layer is cut into equally wide sub-long strips with a width of 7.2 mm at an interval of 90 μm based on P2.

[0103] The fourth channel P4 is to laser or mechanically remove the four sides of the power generation glass, and the edge cleaning width is 10 mm. On the one hand, it provides an insulating substrate for butyl rubber coating, and on the other hand, it ensures the isolation of the power generation area of the power generation glass from the external environment to prevent pollution of the power generation area.

[0104] The lead busbars are sequentially bonded to the back electrode layers on both sides, and the current is led out through the holes in the tempered glass.

[0105] The second PVB film + butyl rubber edge sealing layer, the butyl rubber edge sealing mainly plays a role in edge waterproofing, and the main role of PVB is to bond the power generation glass and the tempered glass into one body; the width of the butyl rubber is 11 mm, the thickness is 0.5 mm, and the thickness of the PVB film is 0.76 mm; the tempered glass protects the middle power generation glass.

[0106] The target materials used in magnetron sputtering are all commercially available target materials. The film thickness is measured by an X-ray fluorescence spectrometer (XRF), the sheet resistance of the film is measured by a four-probe method, and the transmittance of the film is measured by an EVERFINE haze meter. For the specific performance parameter comparison of the CdTe cells obtained in this example, see Table 1 and Figure 5 .

[0107] Example 2

[0108] This example provides a CdTe cell, specifically a CdTe cell with a front electrode of ZnS / Ag / ZnS and a back electrode of molybdenum nitride / aluminum / chromium. Its preparation method includes the following steps:

[0109] For the AR-coated tempered glass, an AR antireflection film coating is applied on its surface by high-temperature sintering and curing, and its light transmittance is above 93%;

[0110] The PVB film of the first PVB film + butyl rubber edge seal layer bonds the AR-coated tempered glass and the ultra-clear float glass into one body; PVB can use high-transmittance high-transmittance PVB, or other colored PVB films can also be selected; the thickness of the PVB film is 0.76 mm; butyl rubber edge sealing mainly plays the role of edge waterproofing and improves the service life.

[0111] The ultra-clear float glass has a light transmittance above 93%.

[0112] On the float glass, a barrier layer SiO is prepared by chemical vapor deposition x , with a thickness of 20 nm.

[0113] On the float glass with a barrier layer, a ZnS / Ag / ZnS layer is sequentially prepared by magnetron sputtering. The background vacuum is of the order of 10 to the -6th power, the sputtering pressure is of the order of 10 to the -3rd power, the flow rate of the process gas is 500 sccm, the wafer flow rate is 1.8 m / min, and the process gas is all argon. The thickness of each layer is 40.18 / 9.07 / 40.09 nm respectively, and the total thickness is about 90 nm. For comparison, the FTO layer is grown in three times by magnetron sputtering, with the thickness of each layer being 32.79 / 177.26 / 177.48 nm respectively, and finally a single-layer FTO layer is formed, with a total thickness of about 388 nm.

[0114] On the ZnS / Ag / ZnS triple layer or the FTO single layer, a high-resistance layer SnO2 is prepared by chemical vapor deposition, with a thickness of 35 nm.

[0115] The power generation layer material is CdSe x Te 1-x , with a thickness of 3.1 μm, where X is 0.03, and it is prepared above the transparent conductive layer.

[0116] The material of the back contact layer is ZnTe:AgyCu1-y, where y is 0.6; the total thickness of the composite film layer is about 41 nm, and it is prepared above the power generation layer.

[0117] The first channel P1 laser scribing uses a laser with a wavelength of 355 nm; the transparent conductive layer / power generation layer / back contact layer is cut into equally wide sub-long strip shapes with a width of 7.2 mm. Insulating glue is filled in the first channel P1 through photolithography technology.

[0118] The second channel P2 laser scribing uses a laser with a wavelength of 532 nm, and the power generation layer / back contact layer is cut into equally wide sub-long strip shapes with a width of 7.2 mm at an interval of 90 μm based on P1.

[0119] A molybdenum nitride / aluminum / chromium layer is sequentially prepared on the back contact layer by magnetron sputtering. The base vacuum is on the order of 10 to the -6th power, the sputtering pressure is on the order of 10 to the -3rd power, the wafer flow rate is 1.8 m / min. The process gas for molybdenum nitride (MoNx) is a mixed gas of nitrogen and argon, with a flow ratio of 3:7 and a total flow rate of 600 sccm. The process gases for aluminum (Al) and chromium (Cr) are both argon, with flow rates of 600 sccm each. The thickness of each layer is 34.65 / 182.17 / 91.03 nm respectively, and the total thickness is about 307 nm. For comparison, a molybdenum (Mo) layer is grown in three times by magnetron sputtering, with each layer thickness being 34.52 / 182.74 / 181.98 nm respectively, and finally a single-layer Mo layer is formed, with a total thickness of about 400 nm. For the specific performance parameter comparison, please refer to the table and the drawings.

[0120] The third channel P3 laser scribing uses a laser with a wavelength of 532 nm, and the power generation layer / back contact layer / back electrode layer is cut into equally wide sub-long strip shapes with a width of 7.2 mm at an interval of 90 μm based on P2.

[0121] The fourth channel P4 is to laser or mechanically remove the four sides of the power generation glass, and the edge cleaning width is 10 mm. On the one hand, it provides an insulating substrate for butyl rubber coating, and on the other hand, it ensures the isolation of the power generation area of the power generation glass from the external environment to prevent pollution of the power generation area.

[0122] The lead busbars are sequentially bonded to the two side back electrode layers, and the current is led out through the holes in the tempered glass.

[0123] The second PVB film + butyl rubber edge sealing layer, with butyl rubber edge sealing, mainly plays the role of edge waterproofing. The main role of PVB is to bond the power generation glass and the tempered glass into one body; the width of the butyl rubber is 11 mm, the thickness is 0.5 mm, and the thickness of the PVB film is 0.76 mm; the tempered glass protects the middle power generation glass.

[0124] The target materials used in magnetron sputtering are all commercially available target materials. The film thickness is tested by an X-ray fluorescence spectrometer (XRF), the sheet resistance of the film is tested by a four-probe method, and the transmittance of the film is tested by an EVERFINE haze meter. For the specific performance parameter comparison of the CdTe cells obtained in this example, see Table 1 and Figure 5 .

[0125] Table 1

[0126]

[0127] From Table 1 and Figure 5 it can be seen that, compared with the single-layer electrode, for the composite electrode, due to the reduction of the film thickness, the increase of the relative yield or the use of lower-cost raw materials, the cost per piece of power generation glass is reduced during continuous production: the cost of Example 1 is reduced by 9.12 yuan per piece compared with the prior art, and the cost of Example 2 is reduced by 10.32 yuan per piece compared with the prior art. At the same time, Figure 5 、 Figure 6 and Figure 7 it can be seen that by improving the transmittance of the transparent electrode in the present invention, more sunlight can pass through, and the power generation layer can absorb more sunlight, thereby converting into more electric energy, thus improving the battery performance; by improving the conductivity of the transparent electrode and the back electrode, the resistance encountered during the internal current transmission of the battery is reduced, thereby improving the battery performance. Among them, the conductivity is characterized by testing the sheet resistance of the film layer with a four-probe method. The lower the sheet resistance, the higher the conductivity. The sheet resistance and transmittance of the composite electrode are integrated in Table 1. 11.4, 9.7, and 10.3 are the sheet resistances of the transparent electrode, and 0.84 and 0.63 are the sheet resistances of the back electrode.

[0128] The various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the present invention; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and single values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within that range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0129] In the present invention, unless otherwise specified, the orientation terms such as "upper" and "lower" specifically refer to the drawing directions in the attached drawings. Additionally, in the description of the specification of the present invention, the terms "comprising", "including", etc. mean "including but not limited to". In this text, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this text, "and / or" describes the associated relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural. In this text, "at least one" means one or more, and "a plurality" means two or more. "At least one kind", "at least one item (individual) below", or similar expressions refer to any combination of these items, including any combination of single item (individual) or plural items (individuals). For example, "at least one item (individual) among a, b, or c", or, "at least one item (individual) among a, b, and c" can both mean: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0130] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A CdTe battery, characterized in that: The preparation method of the CdTe battery comprises the following steps: AR coated tempered glass, the surface of which is coated with AR anti-reflection film coating that is sintered and cured at high temperature, and its light transmittance is above 93%; The PVB film of the first PVB film + butyl adhesive edge sealing layer bonds the AR coated tempered glass and the ultra-clear float glass together; the thickness of the PVB film is 0.76 mm; The light transmittance of the ultra-clear float glass is above 93%; On float glass, barrier layer SiO was prepared by chemical vapor deposition x , thickness is 20nm; ZnS / Ag / ZnS layers were sequentially prepared on float glass with barrier layer by magnetron sputtering method. The background vacuum was 10-6, the sputtering pressure was 10-3, the process gas flow rate was 500sccm, the wafer flow rate was 1.8m / min, the process gas was argon, the thickness of each layer was 40.18 / 9.07 / 40.09nm, and the total thickness was 90nm. A high-resistance layer of SnO2 with a thickness of 35 nm was prepared by chemical vapor deposition on a ZnS / Ag / ZnS triple layer or a FTO single layer; The material of the power generation layer is CdSe x Te 1-x , with a thickness of 3.1 μm, wherein X is 0.03, and is prepared on top of the transparent conductive layer; The material of the back contact layer is ZnTe:AgyCu1-y, where y is 0.6; the total thickness of the composite film layer is 41nm, and it is prepared above the power generation layer; The first channel P1 is laser-scribed using a laser with a wavelength of 355nm; the transparent conductive layer / power generation layer / back contact layer is cut into sub-strips of equal width of 7.2mm; the first channel P1 is filled with insulating glue by photolithography technology; The second channel P2 is laser-scribed using a laser with a wavelength of 532nm. The power generation layer / back contact layer is cut into sub-strips with a width of 7.2mm at intervals of 90μm based on P1. Molybdenum nitride / aluminum / chromium layers were sequentially prepared on the back contact layer by magnetron sputtering. The background vacuum was 10 to the -6th power, the sputtering pressure was 10 to the -3th power, the wafer flow rate was 1.8m / min, the process gas for molybdenum nitride (MoNx) was a mixture of nitrogen and argon, the flow ratio was 3 to 7, and the total flow rate was 600sccm. The process gases for aluminum (Al) and chromium (Cr) were both argon, and the flow rates were all 600sccm. The thickness of each layer was 34.65 / 182.17 / 91.03nm, respectively, and the total thickness was 307nm. The third channel P3 is laser-scribed using a laser with a wavelength of 532nm. The power generation layer / back contact layer / back electrode layer is cut into sub-strips with a width of 7.2mm at intervals of 90μm based on P2. The fourth channel P4 is used to clean the four sides of the power generation glass by laser or mechanical means, and the cleaning width is 10mm; The busbars will be bonded to the back electrode layers on both sides in sequence to lead the current out through the holes in the tempered glass; The second PVB film + butyl rubber edge sealing layer, butyl rubber edge sealing, the width of butyl rubber is 11mm, the thickness is 0.5mm, the thickness of PVB film is 0.76mm; tempered glass protects the middle power generation glass.

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