Electronic and Optical Properties of Delafossite Compounds AgMO2 (M = Al, Ga, In): A Theoretical Study

The study analyzes the energy band structure and phase stability of the delafossite compounds AgMO2 (where M = Al, Ga, In) using the TB-LMTO method and local density approximation. The calculations consider the valence states of the atoms and the optimized c/a ratio of the compounds. The total energy was calculated as a function of reduced volume and fitted with the Birch Murnaghan equation of state. The results show that the 3R polytypes are more stable than the 2H polytypes at ambient conditions. The electronic band structures of the compounds have an indirect band gap and the densities of states are dominated by the Ag 4d states and O 2p states. The band gap values for the AgMO2 compounds decrease in the order of AgAlO2, AgGaO2, and AgInO2 for both the 2H and 3R polytypes. The optical properties of the AgMO2 compounds were also studied using the full potential method. The study provides new insights into the electronic and optical properties of TCOs with potential applications in optoelectronics.