Electronic structure and optical properties of β-CuSCN: A DFT study

Abstract

The electronic structure and optical properties of β-CuSCN is studied within the framework of density functional theory (DFT) formalism. The calculation is carried out within the generalized gradient approximation (GGA) using SIESTA code. The obtained band gap of β-CuSCN is ≈2.3 eV. In the total density of states (TDOS) two prominent peaks are seen at −2.98 eV and −2.36 eV in valence band below Fermi level which is mainly due to Cu-3d states. We have also obtained real (ε1) and imaginary (ε2) parts of dielectric constant, absorption coefficient, optical reflectivity, refractive index and extinction coefficient within the energy range of 0–20 eV. The reflectivity scales up from 14% to 25% in visible region. Value of refractive index changes from 2.23 to 2.96 in visible region. The extinction coefficient and absorption coefficient are almost zero in the visible region. The results show that β-CuSCN can be used as hole transport material (HTM) for development of efficient perovskite solar cells.