The electronic structure, elastic and optical properties of Cu2ZnGe(SexS1- (x))(4) alloys: density functional calculations

The electronic structure, elastic and optical properties of Cu2ZnGe(SexS1 - x)(4) alloys are systematically analysed using first-principles calculations. The lattice parameters agree well with the theoretical and experimental values which are searched as complete as possible indicating our calculations are reliable. The elastic properties are investigated first and are compared with the similar compounds CZTS and CZTSe duet the unavailable experimental data currently. The variation of the optical properties caused by the increase of Se/S ratio is discussed. The static optical constants are calculated and the corrected values are also predicted according to the available experimental data.