First-Principles Calculations of Energy Band for Wurtzite ZnO under Uniaxial Loading along [0001] Direction

Abstract

First-principles calculations are carried out to analyze the variation of the energy gap and the absolute value of the crystal-field splitting energy of wurtzite zinc oxide under uniaxial loading along [0001] direction. The uniaxial loading in [0001] direction is predicted to be more effective to adjust the energy gap than applying the hydrostatic pressure, without changing the direct energy-gap nature. The top of the valence band is sensitive to the uniaxial stress, and the absolute value of the crystal-field splitting energy reaches the minimum when the uniaxial stress is about 2 GPa. The variation in electronic properties originates mainly from the relatively lower density of the valence electrons inc-axis direction.