First principles study of Cu based Delafossite Transparent Conducting Oxides CuXO2 (X=Al, Ga, In, B, La, Sc, Y)

The structural and electronic properties of Cu based Delafossite TCOs (Transparent Conducting Oxides) CuXO2 (X=B, Al, Ga, In, Sc, Y, La) were investigated using a first principles technique of a Full Potential Linearized Augmented Plane wave method. For this study the Perdew, Burke and Ernzerhof gernalized gradient approximation (PBE-GGA), Tran-Blaha modified Beck-Johnson potential (TB-mBJ) and Engel and Vosko generalized gradient approximation (EV-GGA) were used. The computed ground state lattice parameters are in good agreement with published experimental and theoretical data. To the best of acknowledge, the TB-mBJ and EV-GGA are used for the first time for CuBO2 and CuXO2 (X=Sc, Y, La), respectively. The latter approximations provide better band gap values for these compounds compared to previous published data. The density of states plots shows that the valence band maximum for all the studied compounds is mainly formed from a combination of Cu-3d and O-2p states. The broadening of the atom in molecule motivates us to analyze the topology of the electron density with an sophisticated method.