Momentum damping time and phonon-wind force for electron-hole droplets in Ge

Abstract
Time-resolved luminescence imaging is used to investigate the transport properties of electron-hole droplets in Ge. The momentum damping time of droplets is directly obtained by measuring their drift velocity in a calibrated strain field. The magnitude of the phonon-wind force on the droplets is determined by direct comparison to the strain force. The spatial distribution of "hot" electron-hole liquid in the sample is also determined, and the electron intervalley scattering time is measured by a new "streak" method.