EFFECT OF THERMAL PULSES ON RADIATION OF ELECTRON-HOLE DROPS IN Ge.

A new effect is discovered: quenching of the recombination radiation of electron-hole drops by a flux of long-wavelength acoustic phonons and the concurrent appearance in the crystal of a dense free-carrier plasma. The essence of the effect consists in the removal of the drops via the phonon wind from the bulk of the sample to the surface, where the lifetime of the electron-hole pairs is much less than in the bulk. It is found that this phenomenon can be used to determine the surface recombination rate and also the dependence of the velocity of motion of the drops on the power of the applied thermal pulse. The existence of a threshold in the removal of the electron-hole drops is confirmed, and it is shown that this threshold is connected with the trapping of drops by impurity centers.