Copper zinc tin germanium selenium thin film, preparation method thereof and copper zinc tin germanium selenium thin film solar cell

Abstract

The invention relates to a copper zinc tin germanium selenium thin film, which comprises an incident light surface and a back light surface opposite to the incident light surface. Molar ratio of germanium and tin in the copper zinc tin germanium selenium thin film is gradually increased along a direction from the incident light surface to the back light surface. With the change of the molar ratio of the germanium and the tin in the material, the forbidden band width of the copper zinc tin germanium selenium thin film is in a gradient change trend. Due to the forbidden band width in the gradient change trend, potential difference can be produced between the incident light surface and the back light surface, photo-produced electron-hole pairs are separated in a high recombination region, recombination among photo-produced current carriers is avoided, the service life of the photo-produced current carriers is prolonged, the produced potential difference can facilitate the improvement of the diffusion length of the photo-produced current carriers, the collection efficiency of the photo-produced current carriers is improved and the photoelectric conversion efficiency of solar cells is further improved. The invention additionally provides a preparation method of the copper zinc tin germanium selenium thin film and a solar cell using the copper zinc tin germanium selenium thin film.

Description

technical field [0001] The invention relates to photovoltaic technology, in particular to a copper-zinc-tin-germanium-selenium thin film, a preparation method for a copper-zinc-tin-germanium-selenium thin film and a copper-zinc-tin-germanium-selenium thin film solar cell. Background technique [0002] Thin-film solar cells are low in cost and light in weight, can be fabricated into devices on a variety of cheap substrates, and are convenient for mass production, which is an important direction for the development of solar cells in the future. It has the advantages of high photovoltaic efficiency and low cost, and because the earth reserves of copper, zinc, tin and selenium in the alloy materials of thin-film solar cells are very rich, and it does not contain toxic components, it overcomes the resource bottleneck of thin-film solar photovoltaic materials. With the ability of sustainable development in the field of large-scale photovoltaic power generation, it will be a compet...

AI Technical Summary

Problems solved by technology

[0004] Although the efficiency of indium-free copper-based compound thin-film solar cells represented by copper-zinc-tin-sulfur has been significantly improved in the past two years, the diffusion length of carriers in this type of thin-film solar cells is relatively small, resulting in the generation of The charge cannot be collected effectively, and the photoelectric conversion efficiency is not high

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