CN102751373B - Cadmium telluride silica-base film composite solar battery - Google Patents

Abstract

A kind of cadmium telluride silica-base film composite solar battery, including being arranged on upper surface of substrate back electrode, it is arranged on the bottom battery knot of back electrode upper surface, it is arranged on the preceding electrode that bottom battery ties surface, it, which also includes being arranged on bottom battery, ties battery knot in 0~5 knot on surface, middle battery ties surface and sets the top battery knot connected with bottom battery knot and middle battery knot, preceding electrode is arranged on the upper surface of top battery knot, in addition to is arranged between bottom battery knot and middle battery knot or is arranged on middle battery knot and push up the conductive semi reflective layer in centre between battery knot.The present invention has the advantages that solar energy high conversion efficiency, the thermal efficiency are high, production cost is low, is easy to carry, and can be used as solar cell.

Description

Cadmium Telluride-Silicon Based Thin Film Composite Solar Cell

technical field

The invention belongs to the technical field of solar cells, in particular to cadmium telluride solar cells.

Background technique

The research report of the United Nations shows that the energy consumption index is an important index to measure the social development and level of prosperity. In order to further improve the quality of life, especially the subsistence life in poor areas, electricity consumption needs to increase more than ten times from the current level. At present, human beings mainly have thermal power generation, hydropower generation, and nuclear power technology. The fossil fuel energy used in thermal power generation not only brings civilization and progress to people, but also brings increasingly serious environmental pollution. Fossil fuels have become less and less and are on the verge of being exhausted. The utilization of hydroelectric power generation has reached its peak, and no further significant development is possible. Nuclear power technology has always been a national defense and strategically sensitive technology, and nuclear waste is difficult to deal with. In April 2011, the Fukushima nuclear power plant in Japan was damaged by an earthquake and tsunami and leaked a large amount of nuclear radiation. The safety of nuclear power plants is even more daunting.

Solar energy is inexhaustible and inexhaustible energy. The utilization of solar energy will not cause environmental pollution. Therefore, the utilization of solar energy has been valued by countries all over the world. Solar energy products are currently widely used, such as solar water heaters and solar collectors. , solar cells, etc. Solar cells include silicon thin film cells, single (poly) crystalline silicon cells, silicon thin film cells, cadmium telluride cells, and copper indium gallium selenide cells. Crystalline silicon technology is the first generation of traditional technology with low technical content and a long history. The initial investment Relatively low, currently occupying most of the market. However, because a lot of relatively expensive crystalline silicon materials are used; the manufacturing process of silicon thin film batteries consumes a lot of energy, and the energy return period is too long; the manufacturing process of cadmium telluride batteries produces too much pollution, and the cost of cadmium telluride products is currently low. The leader; the advantage of copper indium gallium selenide is that the laboratory has high initial efficiency. Although there are only a few market products, the use efficiency is far lower than its laboratory efficiency. The steam is extremely sensitive, and the key element CdTe has low earth content and high toxicity.

At present, the cost of solar cell power generation is still much higher than that of traditional thermal power generation and hydropower generation.

The cadmium sulfide/cadmium telluride products of First Solar in the United States have spread all over the world, and many large solar cell power stations have been built. As of November 2011, the cumulative power generation capacity reached 5,000 megawatts (5GW).

Cadmium sulfide is a beige substance that absorbs blue light and is unstable under strong ultraviolet light.

The patent number is 201010274863.X, and the invention name is "A CdTe battery transition layer and its preparation method and CdTe". Its main structure is a glass substrate, a transparent conductive layer, a CdS layer, a CdTe layer, The transition layer and the back electrode constitute. The transition layer is a multilayer structure in which ZnTe and Cu layers are stacked alternately. The main disadvantages of this solar cell are its complex structure and low thermal efficiency.

In the field of solar energy technology, a technical problem that needs to be solved urgently is to provide a solar cell with high solar energy conversion efficiency and low product cost.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the above-mentioned shortcomings of the solar cell, and provide a cadmium telluride-silicon-based thin-film composite solar cell with high conversion efficiency and low product cost.

The technical solution adopted to solve the above technical problems is: it includes a back electrode arranged on the upper surface of the substrate, a bottom cell junction arranged on the upper surface of the back electrode, and a front electrode arranged on the upper surface of the bottom cell junction; The 0-5 middle battery junctions on the upper surface of the battery junctions, the top battery junction connected in series with the bottom battery junction and the middle battery junction are arranged on the upper surface of the middle battery junction, and the front electrode is arranged on the upper surface of the top battery junction.

The bottom cell junction of the present invention is composed of a p-type cadmium telluride film, an n-type cadmium sulfide film or a cadmium sulfide-zinc sulfide alloy film, the p-type cadmium telluride film is arranged on the upper surface of the back electrode, and the n-type cadmium sulfide film The film or the cadmium sulfide-zinc sulfide alloy film is arranged on the upper surface of the p-type cadmium telluride film, and the cadmium sulfide-zinc sulfide alloy film is composed of a material represented by the general formula CdxZn1-xS, where 0≤x<1.

The battery junction of the present invention is an amorphous silicon thin film middle battery junction or a nano silicon thin film battery junction or an amorphous silicon germanium thin film battery junction or a nano silicon germanium thin film battery junction.

Battery junction or nano-silicon thin film battery junction or amorphous silicon-germanium thin-film battery junction or nano-silicon-germanium thin-film battery junction in the amorphous silicon thin film of the present invention all comprises p-, i-, n-layer, and p-layer is p-type Semiconductor film, the i-layer is an intrinsic type semiconductor film, the n-layer is an n-type semiconductor film, the p-layer is arranged on the upper surface of the bottom cell junction, the i-layer is arranged on the upper surface of the p-layer, and the n-layer is arranged on the i-layer upper surface.

The top cell junction of the present invention is a silicon thin film top cell junction.

The silicon thin film top cell junction of the present invention is an amorphous silicon thin film top cell junction.

The amorphous silicon thin film top cell junction of the present invention comprises p-, i-, n layers, the p layer is a p-type semiconductor film, the i-layer is an intrinsic type semiconductor film, and the n-layer is an n-type semiconductor film, p The - layer is arranged on the upper surface of the bottom cell junction or the middle cell junction, the i-layer is arranged on the upper surface of the p-layer, and the n-layer is arranged on the upper surface of the i-layer.

The substrate of the present invention is a stainless steel sheet with a thickness of no more than 0.15mm or a polymer material substrate with a thickness of no more than 2mm coated with a metal film; the polymer material is polyimide, polyvinyl fluoride, and a density > 1.55g /cm ³ of any one of the polyvinyl chloride.

The invention also includes an intermediate conductive semi-reflective layer disposed between the bottom cell junction and the middle cell junction and/or between the middle cell junction and the top cell junction.

The thickness of the bottom cell junction of the present invention is at least 1000 nm. The thickness of the middle cell junction of the present invention is 250-2000nm, and the thickness of the top cell junction of the present invention is at least 200nm.

The present invention uses amorphous silicon to convert blue-band light and combines cadmium telluride to improve the conversion efficiency of solar energy and reduce the cost of solar cells; the bottom cell is connected in series with the middle cell and the top cell to form a multi-junction cell, and the bottom cell uses tellurium Cadmium chloride, cadmium sulfide or cadmium sulfide-zinc sulfide alloy coating improves the transparency of solar cells, increases stability and stability efficiency, and improves the conversion rate and thermal efficiency of cadmium telluride solar cells; the substrate is made of stainless steel with a thickness not exceeding 0.15mm A thin sheet or a polymer material substrate coated with a metal film on the surface with a thickness of no more than 2mm. The substrate is flexible, light in weight, and has high power generation efficiency per unit weight. The prepared solar cells can be rolled up and carried around. The invention has the advantages of high solar energy conversion efficiency, high thermal efficiency, low production cost, portability, etc., and can be used as a solar cell.

Fig. 1 is a schematic structural diagram of Embodiment 1 of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and various embodiments, but the present invention is not limited to these embodiments.

Example 1

In Fig. 1, the cadmium telluride-silicon-based thin film composite solar cell of this embodiment consists of a front electrode 1, a top cell junction 2, a middle cell junction 3, a middle conductive semi-reflective layer 4, a bottom cell junction 5, a back electrode 6, The base 7 is connected to form.

The substrate 7 of this embodiment is made of a soft stainless steel sheet with a thickness of 0.1 mm, and the thickness of the stainless steel sheet is not more than 0.15 mm. The substrate 7 of this structure is flexible, light in weight, and has high power generation efficiency per unit mass. The prepared solar cell Can be curled up and taken anywhere. The substrate 7 in this embodiment may also be a glass substrate. The back electrode 6 is plated on the upper surface of the substrate 7, and the back electrode 6 is made of metal molybdenum thin film. The upper surface of the back electrode 6 is plated with a p-type cadmium telluride film, and the upper surface of the p-type cadmium telluride film is plated with an n-type cadmium sulfide film. The p-type cadmium telluride film and the n-type cadmium sulfide film constitute the present embodiment. The bottom cell junction 5, the thickness of the bottom cell junction 5 is 1000nm, and can also be greater than 1000nm, the upper surface of the bottom cell junction 5 is plated with an intermediate conductive semi-reflective layer 4, and the upper surface of the intermediate conductive semi-reflective layer 4 is plated with a middle cell junction 3 , the middle conductive semi-reflective layer 4 has good light transmission in the long-wavelength band, and has good light-reflectivity in the short-wavelength band, and reflects the unabsorbed part of the light back to the middle battery junction 3, which can reduce the light intensity of the middle battery junction 3. Thickness increases the conversion efficiency of stable solar cells.

The battery junction 3 in this embodiment is the battery junction in the amorphous silicon film, the battery junction in the amorphous silicon film includes p-, i-, n-layers, the p-layer is a p-type semiconductor thin film, and the i-layer is this The n-layer is an n-type semiconductor film, the p-layer is plated on the upper surface of the bottom cell junction 6, the i-layer is plated on the upper surface of the p-layer, and the n-layer is plated on the i-layer surface. The thickness of the middle cell junction 3 in this embodiment is 300 nm, the thickness of the middle cell junction 3 may also be 250 nm, and the thickness of the middle cell junction 3 may also be 350 nm. The top battery junction 2 is plated on the upper surface of the middle battery junction 3 by randomly selecting within the range of 250-350 nanometers.

The top cell junction 2 of this embodiment is an amorphous silicon thin film top cell junction, and the amorphous silicon thin film top cell junction is an embodiment of a silicon thin film top cell junction. The amorphous silicon thin film top cell junction includes p-, i-, n - layer, the p-layer is a p-type semiconductor film, the i-layer is an intrinsic type amorphous silicon semiconductor film, the n-layer is an n-type semiconductor film, the p-layer is plated on the upper surface of the battery junction 3, and the i- The layer is plated on the upper surface of the p-layer and the n-layer is plated on the upper surface of the i-layer. The thickness of the top cell junction 2 is 200nm, or greater than 200nm. The top cell junction 2 is connected in series with the middle cell junction 3 and the bottom cell junction 5 .

Example 2

The cadmium telluride-silicon-based thin film composite solar cell of this embodiment is composed of a front electrode 1, a top cell junction 2, a middle cell junction 3, a middle conductive semi-reflective layer 4, a bottom cell junction 5, a back electrode 6, and a substrate 7.

The structures of the substrate 7 , the back electrode 6 , the bottom cell junction 5 , the middle conductive semi-reflective layer 4 and the connections between the structural layers in this embodiment are the same as those in the first embodiment. The upper surface of the bottom cell junction 5 is plated with the middle cell junction 3 . The battery junction 3 in this embodiment is the battery junction in the amorphous silicon film, the battery junction in the amorphous silicon film includes p-, i-, n-layers, the p-layer is a p-type semiconductor thin film, and the i-layer is this The n-layer is an n-type semiconductor film, the p-layer is plated on the upper surface of the bottom cell junction 6, the i-layer is plated on the upper surface of the p-layer, and the n-layer is plated on the i-layer surface. The thickness of the middle cell junction 3 in this embodiment is 300 nm, the thickness of the middle cell junction 3 may also be 250 nm, and the thickness of the middle cell junction 3 may also be 350 nm, which is arbitrarily selected within the range of 250-350 nm. The top cell junction 2 is plated on the upper surface of the middle cell junction 3 , the structure of the top cell junction 2 is the same as that in Embodiment 1, and the top cell junction 2 is connected in series with the middle cell junction 3 and the bottom cell junction 5 . Other structural layers and the connection relationship between the structural layers and the structural layers are the same as those in Embodiment 1.

Example 3

The cadmium telluride-silicon-based thin film composite solar cell of this embodiment is composed of a front electrode 1, a top cell junction 2, a middle cell junction 3, a middle conductive semi-reflective layer 4, a bottom cell junction 5, a back electrode 6, and a substrate 7.

The structures of the substrate 7 , the back electrode 6 , the bottom cell junction 5 , the middle conductive semi-reflective layer 4 and the connections between the structural layers in this embodiment are the same as those in the first embodiment. The upper surface of the bottom cell junction 5 is plated with the middle cell junction 3 . The battery junction 3 in this embodiment is the battery junction in the amorphous silicon film, the battery junction in the amorphous silicon film includes p-, i-, n-layers, the p-layer is a p-type semiconductor thin film, and the i-layer is this The n-layer is an n-type semiconductor film, the p-layer is plated on the upper surface of the bottom cell junction 6, the i-layer is plated on the upper surface of the p-layer, and the n-layer is plated on the i-layer surface. The thickness of the middle cell junction 3 in this embodiment is 300 nm, the thickness of the middle cell junction 3 may also be 250 nm, and the thickness of the middle cell junction 3 may also be 350 nm, which is arbitrarily selected within the range of 250-350 nm. The top cell junction 2 is plated on the upper surface of the middle cell junction 3 , the structure of the top cell junction 2 is the same as that in Embodiment 1, and the top cell junction 2 is connected in series with the middle cell junction 3 and the bottom cell junction 5 . Other structural layers and the connection relationship between the structural layers are the same as in Embodiment 1.

Example 4

In the above embodiments 1-3, the middle battery junction 3 is a nano-silicon thin film battery junction, and the nano-silicon thin film battery junction includes p-, i-, n-layers, the p-layer is a p-type semiconductor thin film, and the i-layer It is an intrinsic type nano-silicon semiconductor film, the n-layer is an n-type semiconductor film, the p-layer is plated on the upper surface of the bottom cell junction 6, the i-layer is plated on the upper surface of the p-layer, and the n-layer is plated on the i-layer upper surface. The thickness of the middle battery junction 3 in this embodiment is 1000nm, the thickness of the middle battery junction 3 can also be 1500nm, and the thickness of the middle battery junction 3 can also be 2000nm, which can be selected arbitrarily within the range of 1000-2000nm. The thickness of the middle battery junction 3 Same as the corresponding embodiment. The other structural layers and the thicknesses of the structural layers and the coupling relationship between the structural layers are the same as the corresponding embodiments.

Example 5

In the above embodiments 1-3, the middle battery junction 3 is an amorphous silicon germanium thin film battery junction, and the amorphous silicon germanium thin film battery junction includes p-, i-, n-layers, and the p-layer is a p-type semiconductor thin film , the i-layer is an intrinsic type amorphous silicon germanium semiconductor film, the n-layer is an n-type semiconductor film, the p-layer is plated on the upper surface of the bottom cell junction 6, the i-layer is plated on the p-layer upper surface, and the n- layer is plated on the i-layer upper surface. The thickness of the middle battery junction 3 is the same as that of Example 1. The other structural layers and the thicknesses of the structural layers and the coupling relationship between the structural layers are the same as the corresponding embodiments.

Example 6

In the above embodiments 1-3, the middle battery junction 3 is a nano-silicon-germanium thin-film battery junction, and the nano-silicon-germanium thin-film battery junction includes p-, i-, n-layers, and the p-layer is a p-type semiconductor thin film, i The -layer is an intrinsic type nano-silicon germanium semiconductor film, the n-layer is an n-type semiconductor film, the p-layer is plated on the upper surface of the bottom cell junction 6, the i-layer is plated on the p-layer upper surface, and the n-layer is plated on On the upper surface of the i-layer, the thickness of the middle battery junction 3 in this embodiment is 1000nm, the thickness of the middle battery junction 3 can also be 1500nm, and the thickness of the middle battery junction 3 can also be 2000nm, which can be selected arbitrarily within the range of 1000-2000nm. The other structural layers and the thicknesses of the structural layers and the coupling relationship between the structural layers are the same as the corresponding embodiments.

Example 7

In the above embodiments 1 to 6, the middle battery junction 3 is plated on the upper surface of the bottom battery junction 5, and the coating material and thickness of the middle battery junction 3 are the same as those in the corresponding embodiments, and the upper surface of the middle battery junction 3 is plated with an intermediate conductive layer. The semi-reflective layer 4, the middle conductive semi-reflective layer 4 has good light transmittance in the long-wavelength band, and has good light-reflectivity in the short-wavelength band. The upper surface of the middle conductive semi-reflective layer 4 is coated with the battery junction 2, and other structures The thicknesses of the layers and the structural layers and the coupling relationship between the structural layers are the same as those of the corresponding embodiments.

Example 8

In the above embodiments 1-6, the middle conductive semi-reflective layer 4 is plated on the upper surface of the bottom battery junction 5, and the upper surface of the middle conductive semi-reflective layer 4 is plated with the middle battery junction 3, the coating material and the thickness of the middle battery junction 3 Same as the corresponding embodiment, the upper surface of the battery junction 3 is coated with an intermediate conductive semi-reflective layer 4, the intermediate conductive semi-reflective layer 4 has good light transmission in the long wavelength band, and has better light transmission in the short wavelength band. Reflective properties, the upper surface of the middle conductive semi-reflective layer 4 is coated with the top battery junction 2, other structural layers and the thickness of the structural layers and the connection relationship between the structural layers are the same as those of the corresponding embodiments.

Example 9

In the above embodiments 1 to 8, the top cell junction 2 is plated on the upper surface of the bottom cell junction 5. There is no middle cell junction in this embodiment, and the structure of the top cell junction 2 is the same as that of Embodiment 1. The top cell junction 2 and the bottom cell junction The battery junctions 5 are connected in series, and the substrate 7 , the back electrode 6 and the front electrode 1 are the same as those in the first embodiment.

Example 10

In the above embodiments 1-8, the middle conductive semi-reflective layer 4 is plated on the upper surface of the bottom battery junction 5, and the upper surface of the middle conductive semi-reflective layer 4 is plated with the middle battery junction 3 in each junction. The material and thickness of the coating film are the same as those in the corresponding embodiment. The upper surface of the battery junction 3 in the uppermost junction is plated with the top battery junction 2. The structure of the top battery junction 2 is the same as that in Embodiment 1. The top battery junction 2 and the battery junction 3 in the top junction 3 are the same. , the bottom cell junction 5 connected in series, the substrate 7, the back electrode 6, and the front electrode 1 are the same as in the first embodiment.

Example 11

In the above embodiments 1-8, the upper surface of the bottom battery junction 5 is plated with an intermediate conductive semi-reflective layer 4, and the upper surface of the middle conductive semi-reflective layer 4 is plated with the middle battery junction 3 in 5 junctions. The material and thickness of the coating film are the same as those in the corresponding embodiment. The upper surface of the battery junction 3 in the uppermost junction is plated with the top battery junction 2. The structure of the top battery junction 2 is the same as that in Embodiment 1. The top battery junction 2 is connected to the middle battery junction 3 and the bottom junction. The battery junctions 5 are connected in series, and the substrate 7 , the back electrode 6 and the front electrode 1 are the same as those in the first embodiment.

Example 12

In the above embodiments 1-11, the bottom cell junction 5 is plated on the upper surface of the back electrode 6, and the bottom cell junction 5 of this embodiment is composed of a p-type cadmium telluride thin film and a cadmium sulfide-zinc sulfide alloy thin film, p The -type cadmium telluride film is plated on the upper surface of the back electrode 6, and the upper surface of the p-type cadmium telluride film is plated with a cadmium sulfide-zinc sulfide alloy film, and the cadmium sulfide-zinc sulfide alloy film is composed of a material represented by the general formula CdxZn1-xS , where 0≤x<1, in this embodiment x is 0.5, that is, Cd _0.5 Zn _0.5 S, and the thickness of the cadmium sulfide-zinc sulfide alloy thin film is 20nm, or greater than 20nm. The other structural layers and the thicknesses of the structural layers and the coupling relationship between the structural layers are the same as the corresponding embodiments.

Example 13

In the above embodiments 1-11, the bottom cell junction 5 is plated on the upper surface of the back electrode 6, and the bottom cell junction 5 of this embodiment is composed of a p-type cadmium telluride thin film and a cadmium sulfide-zinc sulfide alloy thin film, p The -type cadmium telluride film is plated on the upper surface of the back electrode 6, and the upper surface of the p-type cadmium telluride film is plated with a cadmium sulfide-zinc sulfide alloy film, and the cadmium sulfide-zinc sulfide alloy film is composed of a material represented by the general formula CdxZn1-xS , where 0≤x<1, in this embodiment x is 0, that is, the thickness of the ZnS, cadmium sulfide-zinc sulfide alloy thin film is 20nm, and can also be greater than 20nm. The other structural layers and the thicknesses of the structural layers and the coupling relationship between the structural layers are the same as the corresponding embodiments.

Example 14

In the above embodiments 1-11, the bottom cell junction 5 is plated on the upper surface of the back electrode 6, and the bottom cell junction 5 of this embodiment is composed of a p-type cadmium telluride thin film and a cadmium sulfide-zinc sulfide alloy thin film, p The -type cadmium telluride film is plated on the upper surface of the back electrode 6, and the upper surface of the p-type cadmium telluride film is plated with a cadmium sulfide-zinc sulfide alloy film, and the cadmium sulfide-zinc sulfide alloy film is composed of a material represented by the general formula CdxZn1-xS , where 0≤x<1, where x is 0.9, that is, Cd _0.9 Zn _0.1 S, and the thickness of the cadmium sulfide-zinc sulfide alloy film is 20nm, or greater than 20nm. The other structural layers and the thicknesses of the structural layers and the coupling relationship between the structural layers are the same as the corresponding embodiments. When x is 1, it will be a cadmium sulfide film, the same as the prior art

Example 15

In the above embodiments 1 to 14, the substrate 7 is a polyimide substrate with a thickness of 1 mm and a polyimide substrate with a metal film on the surface, and a polyvinyl fluoride substrate with a thickness of 1 mm and a metal film can also be used. The surface with a thickness of 1mm is coated with a polyvinyl chloride substrate with a metal film density > 1.55g/ ^cm3 , and the thickness of the substrate 7 of different materials is not more than 2mm. The thickness of other structural layers and the connection relationship between the structural layers and the corresponding The embodiment is the same. The substrate 7 of this structure is flexible, light in weight, and has high power generation efficiency per unit mass. The prepared solar cell can be rolled up and carried around.

Claims (1)

1. a kind of cadmium telluride-silica-base film composite solar battery, it is made up of the connection of following parts：In substrate (7) upper surface Be provided with back electrode (6), back electrode (6) upper surface is provided with bottom battery knot (5), bottom battery knot (5) by p-type Cadimium telluride thin film, N-type cadmium sulfide-zinc sulphide alloy firm is formed, and its formula of is Cd_xZn_1-xS, x is 0.5 in formula, and p-type Cadimium telluride thin film is set Put in back electrode (6) upper surface, n-type cadmium sulfide-zinc sulphide alloy firm is arranged on p-type Cadimium telluride thin film upper surface, bottom electricity Pond knot (5) upper surface is provided with battery knot (3) in 0~5 knot, and middle battery knot (3) upper surface is set and bottom battery knot (5) and middle electricity The top battery knot (2) of pond knot (3) series connection, the upper surface of top battery knot (2) are provided with preceding electrode (1), in bottom battery knot (5) with Middle conductive semi reflective layer (4) is provided between battery knot (3) and/or between middle battery knot (3) and top battery knot (2), its It is characterised by：The surface that described substrate (7) is thickness no more than 2mm is coated with the high polymer material substrate of metallic film, high score Sub- material is polyimides, polyvinyl fluoride, density ＞ 1.55g/cm³Polyvinyl chloride in any one.