Electronic and Thermal Properties of Monolayer MoS2: A First-Principles Study

Abstract

Electronic band structure and effect of temperature on the thermal properties of monolayer MoS2 have been investigated in the present work. The electronic structure calculations are performed using plane wave pseudopotential method based on density functional theory in the monolayer-MoS2, the band gap of 1.64 eV was found to be direct at K-point. All temperature dependent calculations were performed using First-Principles calculations based on Quasi-Harmonic Approximation (QHA). Transport properties of MoS2, have been calculated through Projector-augmented waves (PAW) method as implemented in Quantum Espresso software. At room temperature (300K), the values obtained for specific heat Cv is 61.12 J/K/mol, free energy F is 76.706KJ/mol and entropy is 31.68 J/K/mol. In our study, we have found that Cv follows T3 law at low temperatures and gradually turn almost linear as temperature increases. Also, we have found that, entropy is sensitive to temperature. The thermal response of free energy is also studied which shows a decrement with raising temperature. Confinement of bulk MoS2 in a 2D monolayer is a way to engineer 3D nanoparticles having a direct band gap and high potential transport properties.