Picosecond Optical Measurements of Band-to-Band Auger Recombination of High-Density Plasmas in Germanium

Abstract

The recombination kinetics of transient high-density electron-hole plasmas in germanium has been measured by time-resolved free-carrier absorption with picosecond optical pulses. Density-dependent recombination rates as high as 4 \ifmmode\times\else\texttimes\fi{} ${10}^{9}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ have been observed in plasmas with initial densities up to 3.4 \ifmmode\times\else\texttimes\fi{} ${10}^{20}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. At this density the band-to-band Auger rate constant, ${\ensuremath{\gamma}}_{3}={n}^{\ensuremath{-}3}\frac{\ensuremath{\partial}n}{\ensuremath{\partial}t}$, is found to be 1.1 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}31}$ ${\mathrm{cm}}^{6}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ at room temperature in germanium.