CIGS/CGS double-junction laminated thin film solar cell

Abstract

The invention relates to a CIGS / CGS double-junction laminated thin film solar cell. The CIGS / CGS double-junction laminated thin film solar cell comprises a narrow-band-gap CIGS bottom battery and a wide-band-gap CGS top battery and is characterized in that the bottom battery and the top battery are connected in series into a whole by the interior of a connection layer, the connection layer comprises a transparent metal oxide conductive layer and a nanometer metal conductive layer, the transparent metal oxide conductive layer is arranged on the bottom battery, the nanometer metal conductive layer is arranged on the top battery, a conductive window of the CGS top battery comprises an ITO composite conductive thin film layer and an ITO thin film layer, and a silicon nitride anti-reflection layer is arranged on the surfaces of the conductive window layer and an electrode layer of the CGS top battery. In the CIGS / CGS double-junction laminated thin film solar cell, a transparent metal oxide and a nanometer metal thin film are combined as the connection layer of the bottom battery and the top battery, the problem of process compatibility between the bottom battery and the top battery is solved, the internal electrical connection between the bottom battery and the top battery is achieved, the cell fabrication process is simplified, the cell fabrication cost is reduced, the cell is simple in structure, meanwhile, the conductive window layer is high in transmittance and electric conductivity and good in passivation effect, the series resistance is low, and the photoelectric conversion efficiency of the thin film solar cell is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of thin film solar cells, in particular to a CIGS / CGS double-junction laminated thin film solar cell. Background technique [0002] At present, the solar cells used in the market are still dominated by the first-generation monocrystalline silicon / polycrystalline silicon cells, but the second-generation thin-film solar cells are recognized as the main direction of solar cell development in the future. Thin-film solar cells refer to solar cells made of materials with a thickness on the order of microns, which is one of the most effective ways to greatly reduce the cost of solar cells. Among many thin-film solar cells, I-III-VI compound semiconductor copper indium (gallium) selenium thin-film solar cells (also known as Cu(In,Ga)Se2 (referred to as CIGS) thin-film solar cells) are known for their high conversion efficiency and long-term stability. The advantages of good performance and strong radiation resistan...

AI Technical Summary

Problems solved by technology

Currently known I-III-VI chalcopyrite compound semiconductor double-junction thin-film solar cells have realized that the top cell adopts a wide bandgap semiconductor material and a transparent conductive oxide as the back contact, which improves the conversion efficiency of the solar cell, but due to the I- The III-VI chalcopyrite compound cannot realize the tunnel junction, the process compatibility between the bottom cell and the top cell is poor, and the direct internal connection between the bottom cell and the top cell cannot be directly connected, and the external cascading method is often used. As a result, the entire cell needs three One or four contacts make the structure of the battery complex and increase the manufacturing cost of the battery

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