Identification of the position of piezoelectric polarization at the MoS2/metal interface

Abstract

Transition-metal dichalcogenides (TMDCs), such as MoS2, lack their inversion center in monolayers, exhibiting in-plane piezoelectricity at a nanoscale thickness. In conventional piezoceramics devices, the operating mechanism has been well established that piezocharges appear at crystal edges and how these charges act in capacitor structures. Although TMDC monolayers are expected to possess a unique system due to their semiconductor nature, strong interaction with contact metals alters physical properties predominantly. In this study, we identify the position of piezocharges in MoS2 generators based on the displacement current under dynamic strain. The present results provide new insights for future device engineering.