Electronic and Optical Properties of Spinel TCOs: Cd2SnO4, Zn2SnO4, and CdIn2O4

Using the band-structure method, we have studied the electronic and optical properties of the transparent conducting oxides SnZn2O4, SnCd2O4, and CdIn2O4. We analyzed the atomic and orbital characters of the band edge states and explained the general trends observed in the fundamental band gap, the optical band gap, the energy difference between the first and the second conduction bands, and the electron effective mass. General rules for designing more efficient transparent conducting oxides are proposed