First Principles Study of Molybdenum Disulfide Electronic Structure

The study of two dimensional material has gain interest due to unique properties which are different from the bulk precursors. Mono- and few-layered of Transition metal dichalcogenides (TMDCs) has band gap properties between 1-2 eV that suitable of FET devices or any optoelectronic devices. Among TMDCs, Molybdenum Disulfide (MoS₂) has gain interest due to its promising band gap-tuning and transition between direct to indirect band gap properties depends on its thickness. First principles calculation by Density Functional Theory has been performed to study the characteristic of MoS₂ electronic structure. Indirect band gap of MoS₂ lies between point Γ to Γ-K in first brillouine zone, while the direct bandgap lies in point-K. The indirect band gap became larger while the number of layer decreased due to quantum confinement effect in c axis direction. In monolayer MoS₂, the indirect band gap become larger than direct one, band gap properties transitioned from indirect to direct. The unique bandgap properties of MoS₂ can lead into better application in energy devices such as solar cell [11], FET [10], and photoluminescence device. (paper)