Effect of Cu concentration and dopant site on the band gap of MoS2: A DFT study

Density functional theory (DFT) calculations have been performed to investigate the structural and electronic properties of molybdenum disulfide (MoS2) by doping a varying concentration of Cu as impurity. Additionally, substitutional site importance has also been elaborated. The results indicate that Cu doping can significantly modify the structural and electronic properties of MoS2. Replacement of single S atom with Cu atom reduces the band-gap to 1.04 eV relative to 1.95 eV of the pristine material. Adopting different arrangements of Cu atoms employing substitutional doping technique we computed a variety of band-gap values varying from 0.14 to 1.95 eV. The PDOS calculations allow us to speak that foreign impurity Cu forms good chemistry with host MoS2. Thus with variant concentration of impurity, band-gap of MoS2 can be tuned to a certain desired level making 2D MoS2 a suitable material for such electronic applications where band-gap is required similar to semiconducting materials. (C) 2020 Elsevier B.V. All rights reserved.