Determination of energy thresholds of electron excitations at semiconductor/insulator interfaces using trap-related displacement currents

Spectral measurements of illumination-induced displacement currents related to trapping of charge carriers optically excited in semiconductor electrodes are shown to deliver information regarding energy onsets of electron transitions at the interface. Presented examples include determination of the conduction band offset at the GaN/Al2O3 interface and determination of charge carrier excitation spectra of two-dimensional (2D) semiconductors MoS2 and WS2 at the interface with insulating SiO2.