Effects of Silicon Impurity on Optical Properties of Sc2C(OH)2 Monolayer: A DFT Study

In the density functional theory (DFT), optical properties of Sc2C(OH)2 monolayer are studied with and without silicon impurity. In the presence of silicon impurity, the structure and properties of this compound were changed from a semiconductor with a 0.57 eV band-gap to a topological insulator with a zero band-gap and a band inversion. With and without the silicon impurity, the spectral features in this compound originate from the electron transition from the p-Si and p-C to d-Sc and s-H, respectively. The values of optical constants are increased in the doped-structure with respect to the pure structure.