CIGS (copper indium gallium selenium) thin film solar cell and preparation method thereof

Abstract

The invention discloses a CIGS (copper indium gallium selenium) thin film solar cell and a preparation method thereof, and belongs to the technical field of the solar cell. The solar cell is formed by successively connecting a substrate, a metal anode, a light absorption layer, a buffer layer, a window layer, a transparent electrode layer and a grid-shaped metal cathode, wherein the light absorption layer consists of at least two layers of CIGS thin films of different energy gaps; and each CIGS single layer of the light adsorption layer is directly formed into the film by regulating the magnetron sputtering pressure, the temperature range and the power density, or a prefabricated layer is prepared by magnetron sputtering; and then, the prefabricated layer is subjected to selenylation processing to obtain the CIGS thin film at the temperature of 400-500DEG C under the protection of argon or nitrogen. Each single layer of CIGS thin film disclosed by the invention has different energy gaps, the shape of the energy band of the light absorption layer can be regulated in a combined mode, the collection and light spectrum response curve of a carrier can be both considered, and the absorption efficiency of the light absorption layer is improved by 30-50%. The CIGS thin film solar cell and the preparation method disclosed by the invention have the advantages of high cell photoelectric conversion efficiency, simple technology, simple required equipment and easiness in realizing mass production.

Description

technical field [0001] The invention belongs to the technical field of solar cells, and relates to the preparation of copper indium gallium selenium thin film solar cells and the structural design of thin film devices, in particular to a copper indium gallium selenium thin film solar cell and a preparation method thereof. Background technique [0002] Copper-indium-selenium-based thin-film solar cells are the new type of thin-film solar cells with the most market prospects because of their outstanding features such as high efficiency, low cost, long life, and flexible substrates. Copper indium selenide (CIS) has a chalcopyrite structure with an energy gap of 1.04 eV. If part of In in CIS is replaced by Ga, CuIn 1-x Ga x Se 2 The energy gap can be continuously adjusted between 1.04 and 1.68 eV, which provides an important theoretical basis for the preparation of copper indium gallium selenium thin film solar cells with adjustable energy gap. At present, the structure of co...

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Problems solved by technology

However, this is an imaginary curve, and it is difficult to precisely control the distribution of Ga at present, so the CIGS energy gap is not easy to reach a parabolic state when the Ga gradient distribution is [Li Wei, Sun Yun, Liu Wei, Li Fengyan, Zhou Lin, Journal of Synthetic Crystals , February 2006, Vol. 35, No. 1, pp. 131-134]

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