Study on the intrinsic defects in ZnO by combing first-principle and thermodynamic calculations

Abstract

In this paper, the intrinsic point defects in ZnO crystal have been studied by the approach that integrates first-principles, thermodynamic calculations and the contributions of vibrational entropy. With temperature increasing and oxygen partial pressure decreasing, the formation energies of oxygen vacancy [Formula: see text], zinc interstitial [Formula: see text] and zinc anti-site [Formula: see text] are decreasing, while it increases for zinc vacancy [Formula: see text], oxygen interstitial [Formula: see text] and oxygen anti-site [Formula: see text]. They are more sensitive to temperature than oxygen partial pressure. There are two interesting phenomena. First, [Formula: see text] or [Formula: see text] have the lowest formation energies for whole Fermi level at special environment condition (such as at [Formula: see text], about [Formula: see text] or [Formula: see text], about [Formula: see text]) and intrinsic [Formula: see text]-type doping of ZnO is possible by [Formula: see text] at these special conditions. Second, [Formula: see text] as donors have lowest formation energy for all Fermi level at high temperature and low oxygen partial pressure [Formula: see text], [Formula: see text]. According to our analysis, the [Formula: see text] could produce [Formula: see text]-type doping in ZnO at these special conditions and change [Formula: see text]-type ZnO to [Formula: see text]-type ZnO at condition from low temperature and high oxygen partial pressure to high temperature and low oxygen partial pressure.