Effects of Electron Beam Irradiation and Thiol Molecule Treatment on the Properties of MoS₂ Field Effect Transistors

We investigated the effects of the structural defects intentionally created by electron-beam irradiation with an energy of 30 keV on the electrical properties of monolayer MoS₂ field effect transistors (FETs). We observed that the created defects by electron beam irradiation on the MoS₂ surface working as trap sites deteriorated the carrier mobility and carrier concentration with increasing the subthreshold swing value and shifting the threshold voltage in MoS₂ FETs. The electrical properties of electron-beam irradiated MoS₂ FETs were slightly improved by treating the devices with thiol-terminated molecules which presumably passivated the structural defects of MoS₂. The results of this study may enhance the understanding of the electrical properties of MoS₂ FETs in terms of creating and passivating defect sites.