Electronic power transfer in pulsed laser excitation of polar semiconductors

Abstract

A time-resolved transport analysis of highly nonequilibrium photoexcited carrier-phonon systems is presented. It is shown that amplification of the most strongly coupling optical-phonon modes leads to a drastic reduction of the intraband cooling rates of the electron-hole plasma. As a consequence and in contrast to earlier expectations, free-carrier screening of the long-range Fröhlich couplings turns out to play only a secondary role. The theory is free of adjustable parameters and in qualitative agreement with hitherto unexplained experimental results from time-resolved transmission spectroscopy of gallium arsenide.