Analysis of electrical and magnetic properties of zinc oxide: A quantum mechanical study

Density functional theory (DFT) and generalized gradient approximation (GGA) have been employed to study origins of the intrinsic n-type electrical conductivity in the zinc oxide. Hubbard-like term has been introduced to provide a better description for the Zn 3d electrons. Two intrinsic point defects, namely oxygen vacancy and hydrogen impurity, were taken into consideration. Results on conductivity are analyzed using density of states patterns for different configurations of defects. Microstructure and local magnetic moments are studied as well. The obtained results clearly indicate that oxygen vacancy does not and cannot be responsible for the intrinsic n-type electrical conductivity whereas inserted hydrogen atoms tend to lose its only valence electron, which in turn becomes a free electron contributing towards the n-type conductivity.