Scanning Tunneling Spectroscopy of Photoexcitations on a Nanosecond Time-Scale

Abstract

ABSTRACTScanning tunneling spectroscopy of the high frequency response of photoexcited carriers in the layered structure semiconductors n–type MoS2 and p–type Wse2 is demonstrated using the beat frequency of the longitudinal modes of a HeNe laser at the tunneling junction. We analyze the optical response taking into account the effects of tip-induced band bending and surface states.