Study on electronic structure and optical properties of bulk and monolayer Ag2Te

In this paper, the electronic structure and optical properties of the bulk Ag2Te and the monolayer Ag2Te with three crystal directions (100), (010), and (001) are calculated by using density functional theory. The calculations include energy band, total density of states, partial density of states, complex dielectric function, complex refractive index, absorption spectrum, reflection spectrum, photoconductivity, and energy loss function. The calculation results show that the bulk Ag2Te is a zero-band gap material, while the bandgap can be effectively opened for single-layer structures. The dielectric constant, light absorption, reflectivity, refractive index, conductivity, and energy loss of the Ag2Te bulk are larger than the monolayer Ag2Te in the (100), (010), and (001) directions. It provides a good theoretical basis for the future application of Ag2Te in optics.