Triaxial strain effect on the electron transport performance and absorption spectrum of ZnO

Abstract

The effect of triaxial strain on the electron transport performance and absorption spectrum of ZnO has been rarely reported. In this paper, the generalized gradient approximation plane wave ultrasoft pseudopotential + U method based on the spin density functional theory is adopted to solve this problem. The first-principle method is utilized to study the triaxial strain on the electron transport performance and absorption spectrum of ZnO. Results show that the binding energy of Zn36O36 is 2.14 eV when the system is unstrained and relatively stable. The formation energy of the Zn36O36 system increases with the increase in tensile or compressive strain, and the system stability decreases. The formation energy of the O-vacancy system is smaller compared with the same orders of magnitude of tensile or compressive strain. The formation energy of O-vacancy system is smaller, and the structure is stable when the system is tensile strain. Specifically, the absorption spectrum of the Zn36O35 system has the optimal redshift and intensity when the tensile strain is 5%. The electron mobility of the Zn36O36 system along the y direction (G → F) is relatively large when the compressive strain is −5%, the band gap of the system is wide, and the blueshift of the absorption spectral distribution is obvious. This work has a certain theoretical guidance for the design and preparation of novel ultraviolet light detectors or improvement of the electron transmission performance.