Optical properties of two-dimensional AlOCl, BaFCl, and BiOCl monolayers using the density functional theory

Abstract

Currently, international investigation effort into the study of optical properties of two-dimensional materials is intense. At the fundamental level, the aim is to understand the structure and dynamics of these nano-objects as well as their interaction with light. Based on the density functional theory, we compute the optical properties such as absorption, conductivity, refractive index, and dielectric function of AlOCl, BaFCl, and BiOCl monolayers. For the three monolayers, we can see clearly that the real part of the dielectric function does not go through the zero levels. Besides, we found that ε2(ω) of the dielectric function disappears at neighboring 24.00 eV, which corresponds to the energy loss function. In this framework, we obtained that the compounds become transparent when the frequency of the incident light is higher than the plasma frequency (24.00 eV). Our GGA results reveal that the value of the static dielectric constants of AlOCl, BaFCl, and BiOCl is 1.35, 1.18, and 1.79, respectively, which can be studied as a suitable dielectric material.