First principles study in the electronic structures and optical properties of chalcogenide-doped AgInS2

The Perdew–Burke–Ernzerhof (PBE) generalized gradient approximation (GGA + U) is adopted to simulate the electronic structures and optical properties of AgInS2 semiconductors with S substitution by chalcogenides. AgIn(S, O)2 semiconductor can be synthesized at the normal conditions due to the formation energy. All chalcogenides doping in AgInS2 remain the semiconductor with the narrow band gaps. In the presence of the impurities, the contributions from p states of chalcogenides are involved, accountable for the reduction of the band gaps. Using the reflectivity and absorption coefficients, the optical properties with extensive absorption range and low reflectivity are attained by incorporating AgInS2 semiconductors with chalcogenides. Finally, this theoretical work launches a broader understanding of the absorber materials and also predicts the natural properties as the alternative for the solar cell applications.