Evidence for Bandgap Opening in Buckled Epitaxial Graphene from Ultrafast Time-Resolved Terahertz Spectroscopy

Abstract

Using ultrafast time-resolved THz spectroscopy, we observe two-orders-of-magnitude increase in the relaxation rate in semiconducting epitaxial graphene relative to pristine epitaxial graphene, attributed to enhancement of the optical-phonon-mediated carrier cooling and recombination over a wide range of electron temperatures.