Strain engineering and electric field tunability of the electronic properties of a two-dimensional ZnGeN2 monolayer

Abstract

In this work, by means of first-principles calculations, we investigate the structural and electronic properties of a two-dimensional ZnGeN₂ monolayer as well as the effects of strain and an electric field. The ZnGeN₂ monolayer is known to be a dynamically stable structure at room temperature. In the ground state, the ZnGeN₂ monolayer possesses semiconducting characteristics with an indirect band gap of 1.73/2.96 eV obtained via PBE/HSE06 calculations. Furthermore, the electronic properties of the ZnGeN₂ monolayer can be manipulated via strain engineering and an electric field. Both biaxial and uniaxial strain give rise to the change in the band gap and lead to the semiconductor-to-metal transition and from an indirect to a direct band gap, while the electric field leads to a decrease in the band gap and gives rise to the semiconductor-to-metal transition. Our findings suggest that the ZnGeN₂ monolayer is a promising candidate for high-performance multifunctional nanodevices.