Copper-zinc-tin-sulfide-selenium film and preparation method thereof as well as copper-zinc-tin-sulfide-selenium film solar cell

Abstract

The invention provides a copper-zinc-tin-sulfide-selenium (CZTSSe) film, which comprises a light-incident surface and a backlight surface opposite to the light-incident surface. The molar ratio of sulfide to selenium in the CZTSSe film is increased gradually along with the direction from the light-incident surface to the backlight surface. The forbidden bandwidth of the CZTSSe film is changed along with the changes of the molar ratio of the sulfide to the selenium in a material. The forbidden bandwidth can cause the generation of potential difference between the light-incident surface and the backlight surface, and photo-induced carriers are driven out of a high recombination area; therefore, recombination among the photo-induced carriers is avoided, and the service liives of the photo-induced carriers are prolonged. The generated potential difference is beneficial to improving the diffusion length of the photo-induced carriers and the collection efficiency of the photo-induced carriers is improved, thus improving the photoelectric conversion efficiency of the cell. The invention further provides a preparation method of the CZTSSe film and a CZTSSe film solar cell.

Description

technical field [0001] The invention relates to photovoltaic technology, in particular to a copper-zinc-tin-sulfur-selenide film, a method for preparing the copper-zinc-tin-sulfur-selenium film and a copper-zinc-tin-sulfur-selenide 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. Copper-zinc-tin-sulfur-selenide (CZTSSe) thin-film solar cells can take into account high efficiency and low cost at the same time. Because the earth reserves of copper, zinc, tin, sulfur and selenium in its alloy materials are very rich and do not contain toxic components, it also overcomes the The resource bottleneck of thin-film solar photovoltaic materials has been overcome, and copper-zinc-tin-sulfur-selenide thin-film solar cells have the ability of sust...

AI Technical Summary

Problems solved by technology

[0004] Traditional copper-zinc-tin-sulfur-selenium thin-film solar cells have short lifespan and low collection efficiency of photogenerated carriers, resulting in low photoelectric conversion efficiency. Therefore, the lifespan and diffusion length of photogenerated carriers need to be greatly improved.

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