Electronic, optical, and transport properties of single-layer ZrTeS₄: a DFT study

In this paper, we propose the novel ZrTeS4 single layer and investigate its properties using first-principles calculations. In the equilibrium state, the ZrTeS4 single layer has an anisotropic lattice with high structural stability. The direct band gap of ZrTeS4 is found to be approximately 1.89 eV. Like other narrow-band-gap 2D materials, ZrTeS4 is rather ductile, however its Poisson's ratio is close to that of graphene. Single-layer ZrTeS4 is expected to be a promising non-linear optical material due to its good birefringence and perfect transparency in most of the infrared region. Single-layer ZrTeS4 is favorable for hole-electron separation because it only allows fast mobility of electrons along the x-axis. The absorption coefficient alpha(omega) is very high in the visible region (at 10(5) cm(-1)) and ultra-violet region (at 10(6) cm(-1)). The electronic and optical properties of single-layer ZrTeS4 can be tuned by applying different strains. It is reasonable to suggest single-layer ZrTeS4 as a good candidate for optoelectronic applications.