First principles study of carrier activity, lifetime and absorption spectrum to investigate effects of strain on the photocatalytic performance of doped ZnO

Abstract

Doping of isovalent (S, Se, and Te) elements in ZnO is a new doping method. However, the factors affecting the photocatalytic performance of a doped system by triaxial strain are often ignored. In this study, we have applied strain on model and performed first-principle calculation to investigate the effect of triaxial strain on the stability of the doped system, red shift of the absorption spectrum, electric dipole moment, and carrier lifetime. Calculation results showed that all doped systems exhibited high binding energy and stability under unstrained conditions. However, when the applied strain was increased, the energy of all the systems increased, and the stability decreased. The stability, red shift of absorption spectrum, electric dipole moment, and carrier lifetime of all doped systems were studied. When the tensile strain was 5%, the red shift of the absorption spectrum and the electric dipole moment of the doped system (Zn36SO35) were the largest. Moreover, the carrier lifetime of the doped system (Zn36SO35) was the longest. Considering the red shift of the absorption spectrum, electric dipole moment, and carrier lifetime, the photocatalytic performance of the doped system (Zn36SO35) was the best, when the tensile strain was 5%.