Ultrafast carrier dynamics in Au/GaAs interfaces studied by terahertz emission spectroscopy

摘要

The measurements of optically generated terahertz emission from Au/GaAs interfaces are investigated in detail. We observe that, under high laser power excitation, terahertz signals from bare GaAs wafers and Au/GaAs samples exhibit an opposite polarity. The polarity-flip behaviors are also observed in temperature-dependent and femtosecond pump-generation studies of the Au/GaAs interfaces.