Preparation of Cu(In,Ga)Se2 thin film solar cells by two-stage selenization processes using N2 gas

The aim of this work is to study the dependence of the structural properties of Cu(In,Ga)Se2 polycrystalline thin films prepared by a two-step selenization of co-evaporated metallic precursors in Se-containing environment under N2 gas flow. Characterizations included studies of morphological features, formation of crystalline phases and the depth compositional uniformity of the final thin films. From these studies optimum growth parameters were determined for the preparation of high-quality chalcopyrite thin films with structural and compositional properties suitable for solar cell applications. The formation and optoelectronic properties of glass/Mo/Cu(In,Ga)Se2/CdS/ZnO/Al-Ni thin film solar cells are also reported. The better conversion efficiencies were around 8.0%.