Sub-Thermionic Steep Switching in Hole-Doped WSe2 Transistors

Decreasing the subthreshold swing (SS) of field-effect transistors (FETs) to sub-60 mV/decade at room temperature can enable next-generation low-power electronics [1]. Here, we demonstrate steep switching and high on-current (ION ≈ 400μA/μm) in non-uniformly hole-doped WSe
₂
transistors. By setting up large lateral electric field gradients through spatial variation of doping, we deduce that the abrupt switching behavior is consistent with avalanche (impact ionization [2]) of charge carriers, opening up a new approach to achieve low-power transistors based on ultra-thin 2D materials.