Tunable electronic properties of InSe by biaxial strain: From bulk to single-layer

In the present work, we consider the electronic properties of bulk and single-layer InSe using the density functional theory. Our calculations show that at the equilibrium state, the single-layer InSe is a semiconductor with an indirect energy bandgap of 1.382 1 eV, nearly twice the bandgap of bulk InSe. Focusing on the effect of biaxial strain ϵ bon electronic properties of single-layer InSe, our calculated results indicate that tensile biaxial strain changes slightly the valence subbands near Fermi level, while the band structure of the single-layer InSe depends tightly on the compressive biaxial strain. Also, the energy gap of the single-layer InSe depends almost linearly on the ϵ b. However, the energy gap tends to increase slowly when the large compressive biaxial strain is applied. We believe that the control of the energy gap of the single-layer InSe by strain engineering can be useful in its application in nanoelectromechanical systems and nanoelectronic devices. © 2019 IOP Publishing Ltd.