A mobility study of monolayer MoS₂on low-κ/high-κ dielectrics

The dielectric environment plays a significant role in the performance of transition metal dichalcogenide FETs. In a previous study, a low mobility of monolayer (ML) MoS2 was extracted when located on an ultrathin dielectric [1]. Here, we have performed a comparative study of ML MoS2 on a number of low-κ/high-κ dielectrics and found that the mobility does not depend on the choice of dielectric if an 'air gap' between the MoS2 and the dielectric is accounted for. This implies that remote phonon scattering plays a small or no role for the transport in MoS2. Moreover, we observed that mobility is independent on carrier concentrations and limited by intrinsic phonon scattering for both low-κ/high-κ dielectrics.