Carrier acceleration under very high fields in bulk GaAs investigated by time-domain terahertz spectroscopy

Abstract

Nonequilibrium electron transport in bulk GaAs under very high electric fields up to 300 kV/cm has been investigated by time-domain terahertz (THz) spectroscopy. It is found that when applied electric field, F, is above 50 kV/cm, the initial acceleration signal in THz emission waveforms starts decreasing with increasing F. This result suggests that the effective acceleration mass of electrons significantly increases with increasing F, most likely due to strong band mixing under very high fields. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.