In(O,OH)S/AgInS2 absorbent layer/buffer layer system for thin film solar cells

In this work In(O,OH)S thin films were deposited on AgInS2 thin films for the system absorbent-layer/buffer-layer to be used in two junctions tandem and/or in single junction solar cells. AgInS2 layers were grown by co-evaporation from metal precursors in a two stage process, and In(O,OH)S thin films were deposited by chemical bath deposition. X-ray diffraction measurements indicated that AgInS₂ thin films grown with chalcopyrite structure; and In(O,OH)S films grown with polycrystalline structure. It was also found that the AgInS₂ films presented p-type conductivity, a high absorption coefficient (greater than 10⁴ cm^-1) and an energy band gap (Eg) of 1.95 eV, and In(O,OH),S thin films presented Eg about 3.01 eV. The results indicate that the developed system can be used in single junction solar cells, and in two junctions tandem solar cell as top cell.