We investigated the geometrical and electronic properties of copper-doped MoS2 by first principles calculations. The doping is done by Cu substitution with Mo (1 to 4 atoms) accompanied by study of S vacancies. Our outcomes show that the concentration of doping and vacancy of S leads to determine and finely tune the band gap in the range of 0.16 to 1.95 eV. This fine tuning of band gap results due to variation in concentration of impurity, changing dopant site, and production of S vacancies. The resulting arrangements show significant charge redistribution on replacement of local atoms with foreign atoms dictated by electronegativity determined from the Bader analysis. In addition, bonding mechanism occurring due to substitution of foreign elements is discussed. These results give pleasing data regarding fine desired value of the band gap of the MoS2 which helps its utilization in semiconductor and other opto-electronic devices in addition to understanding the electrical conductivity.
Keywords: Band gap tuning; Charge density plot; Cohesive energy; DFT; First principles calculations; Impurity concentrations; Partial density of states (PDOS); Substitutional doping; Vacancy creations.