Interaction between free carriers,free excitons,and electron-hole drops in germanium

Under steady-state conditions, we have observed an increase of photo-conductivity in Ge at low temperature simultaneously with radiation from electron-hole drops. A set of rate equations for a 3-phase system of carriers, free excitons and drops are used to interpret the results. Values of the exciton-recombination coefficient and the lifetimes of the three phases are determined.