Theoretical investigation of quantum capacitance in the functionalized MoS2-monolayer
Abstract
In this work, we investigated the electronic structure and the quantum capacitance of the functionalized MoS2 monolayer. The functionalizations have been done by using different ad-atom adsorption on MoS2 monolayer. Density functional theory calculations are performed to obtain an accurate electronic structure of ad-atom doped MoS2 monolayer with a varying degree of doping concentration. The quantum capacitance of the systems was subsequently estimated. A marked quantum capacitance above 200 μF/cm2 has been observed. Our calculations show that the quantum capacitance of MoS2 monolayer is significantly enhanced with substitutional doping of Mo with transition metal ad-atoms. The microscopic origin of such enhancement in quantum capacitance in this system has been analyzed. Our DFT-based calculation shows that generation of new electronic states at the proximity of the band-edge and the shift of Fermi level caused by the ad-atom adsorption results in a very high quantum capacitance in the system.