Abstract
In this paper, we report the research highlight on the preparation and characterization of Indium-free $Cu_2ZnSnSe_4$ and Indium-reduced $CulnZnSe_2$ thin films in order to seek the viability of these absorber materials to be applied in thin film solar cells. The films of $Cu_2ZnSnSe_4\;and\;CulnZnSe_2$ were prepared using mixed binary chalcogenides powders. It was observed that Cu concentration was a function of substrate temperature as well as CuSe mole ratio in the target. Under an optimized condition, $Cu_2ZnSnSe_4\;and\;CulnZnSe_2$ thin films grew with strong [112]. [220/204] and [312/116] reflections. Both $Cu_2ZnSnSe_4\;and\;CulnZnSe_2$ films were found to exhibit a high absorption coefficient of $104^4cm^{-1}\;Cu_2ZnSnSe_4$ film showed a band gap of 1.5eV which closes to the optimum band gap of an ideal solar absorber for a solar cell. On the other side, an increase of optical band gap from 1.0 to 1.25eV was found to be proportional with an increase of Zn concentration in the $CulnZnSe_2$ film. All films in this study revealed a p-type semiconductor characteristic.