Ab initio study on the stability of N-doped ZnO under high pressure

Abstract

We perform first-principles density functional theory calculations to examine the stability of nitrogen-doped wurtzite ZnO under pressure. Our calculations indicate that both the stability of the nitrogen-doped ZnO and the defect concentration increase with pressure. As the pressure increases from 0 to 9 GPa, the density of states at the Fermi level decreases, and the states have a tendency to move to lower energy levels. Electron-localization function and Bader charge analysis have been used to understand the pressure effect on the defect. Under the basic growth conditions (using ε-N₂ for nitrogen atoms), the calculated formation enthalpies decrease with pressure, which suggests a rise in the defect concentration. Applying pressure has great impact on the nitrogen-doped defects, and can be used as an efficient approach to form p-type ZnO.