Preparation of CuIn(S x Se 1– x ) 2 thin films with tunable band gap by controlling sulfurization temperature of CuInSe 2

In this paper, polycrystalline CuIn(S x Se 1– x ) 2 thin films with tunable x and E g (band gap) values were prepared by controlling the sulfurization temperature ( T ) of CuInSe 2 thin films. X-ray diffraction indicated the CuIn(S x Se 1– x ) 2 films exhibited a homogeneous chalcopyrite structure. When T increases from 150 to 500 °C, x increases from 0 to 1, and E g increases from 0.96 to 1.43 eV. The relations between x and E g and the sulfurization process of CuIn(S x Se 1– x ) 2 thin films have been discussed. This work provides an easy and low-cost technique for preparing large area absorber layers of solar cell with tunable E g .