DFT + U study of electronic and optical properties of Cu3TMTe4: TM = V, Nb, Ta with incorporation of SOC

Abstract

Density Functional Theory (DFT) calculations of structural, electronic and optical properties of copper sulvanite compounds (Cu3TMTe4; TM = V, Nb, Ta) was performed by incorporating spin orbit coupling (SOC) and Hubbard (U) correction for Cu-d orbitals. Analysis of the result shows that SOC effect slightly reduces the electronic band gap of each of the copper sulvanite compounds by 0.10–0.12 eV respectively. Furthermore SOC splitting of bands at R symmetry point of the valence band (VB) with split off energy Δso = 0.33, 0.34 and 0.34 eV for V, Nb and Ta family of compounds are respectively observed. Moreover the optical properties fulfill certain condition for promising solar photovoltaic (PV) absorber with minute observed SOC effect. Theoretical prediction provided with DFT + U calculation along with the incorporation of SOC may provide valuable data for development of nanodevices.