Electronic structure analyses of Sn-doped In2O3

Electronic structures of Sti-doped In2O3 (ITO) have been investigated for the first time by using a first-principles calculation method based on the density functional theory. Calculated partial density of states (PDOS) analyses showed that a Sri atom substituted for an indium one formed three impurity bands with s-like symmetry, the second band of the three bands overlapped the conduction band of In2O3, and the Fermi energy of ITO was captured in this impurity band. The PDOS analyses also revealed that the substitution of a Sn atom did not significantly destroy the shape of density of states around the bottom of the conduction band, which gave a physical foundation for the Burstein-Moss shift model used up to now. Carrier generation mechanism and past experimental results, such as those of X-ray photoelectron spectroscopy, temperature dependency of electrical conductivity and carrier-concentration dependency of optical effective mass of ITO, are discussed based on the present theoretical calculation results.