Strain-tunable band parameters of ZnO monolayer in graphene-like honeycomb structure

TL;DR

This study uses ab initio calculations to demonstrate that the electronic properties of ZnO monolayer in a graphene-like structure can be effectively tuned by applying biaxial strain, impacting its potential in nanodevices.

Contribution

It provides the first detailed analysis of how in-plane biaxial strain influences the band parameters of ZnO monolayer in a honeycomb structure.

Findings

Band gap remains direct under strain and varies non-linearly.

Fermi velocity of electrons is comparable to graphene.

Strain tuning affects effective masses and electronic properties.

Abstract

We present ab initio calculations which show that the direct-band-gap, effective masses and Fermi velocities of charge carriers in ZnO monolayer (ML-ZnO) in graphene-like honeycomb structure are all tunable by application of in-plane homogeneous biaxial strain. Within our simulated strain limit of $\pm 10$%, the band gap remains direct and shows a strong non-linear variation with strain. Moreover, the average Fermi velocity of electrons in unstrained ML-ZnO is of the same order of magnitude as that in graphene. The results promise potential applications of ML-ZnO in mechatronics/straintronics and other nanodevices such as the nano-electromechanical systems (NEMS) and nano-optomechanical systems (NOMS).