Study of Energetics of Polaron Dynamics in Monolayer and Bulk MoS₂ Using Oxidation-State Constrained Density Functional Theory

We use oxidation-state constrained density functional theory (OS-CDFT) to study the polaron dynamics in the monolayer and bulk MoS₂ as well as in MoS₂ with the S and Mo vacancies. OS-CDFT is used to calculate the reorganization energies and driving forces of the polaron dynamics in MoS₂. From our study, we find similar polaron hopping energetics for both monolayer and bulk MoS₂. However, polaron hopping near an S vacancy has a high driving force such that it is in the Marcus inverted regime for both monolayer and bulk MoS₂. This can explain the low electron mobility of monolayer MoS₂ found in experiments. Similarly, polaron hopping near an Mo vacancy is in the Marcus inverted regime for both monolayer and bulk MoS₂. However, the driving force near an Mo vacancy is not as large as the driving force near an S vacancy.