Atomic disorder is a common limiting factor for the lowerature mobility in monolayer transition-metal dichalcogenides (TMDs; MX2). Here, we study the effect of often occurring atomic vacancies on carrier scattering and transport in p- and n-type monolayer MoS2. Due to charge trapping in vacancy-induced in-gap states, both neutral and charged vacancies resembling, respectively, short-range and combined short-range and long-range Coulomb scatterers must be considered. Using the T-matrix formalism, we demonstrate a strong renormalization of the Born description of short-range scattering, manifested in a pronounced reduction and a characteristic energy dependence of the scattering rate. As a consequence, carrier scattering in TMDs with charged vacancies is dominated by the long-range Coulomb disorder scattering, giving rise to a strong screening-induced temperature and density dependence of the lowerature carrier mobility. For TMDs with neutral vacancies, the absence of intrinsic Coulomb disorder results in significantly higher mobilities as well as an unusual density dependence of the mobility which decreases with the carrier density. Our work illuminates the transport-limiting effects of atomic-vacancy scattering relevant for high-mobility TMD devices.
Bibliographical noteFunding Information:
K.K. acknowledges support from the Carlsberg Foundation and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant Agreement No. 713683 (COFUNDfellowsDTU). T.L. acknowledges partial support from NSF ECCS-1542202. The Center for Nanostructured Graphene (CNG) is sponsored by the Danish National Research Foundation, Project No. DNRF103.