Role of thermalization phonons in producing the electron-hole droplet cloud

The phonon wind which generates the characteristics cloud of electron-hole droplets in Ge cannot be composed solely of phonons produced via Auger recombination in drops. The nearly constant droplet density in the cloud and the rapid expansion of the cloud both point to an extra source of phonons spatially localized near the crystal surface and formed during the initial thermalization of hot carriers. Most experiments, including recent measurements of droplet velocities, are consistent with about 10–20% of the wind phonons being of thermalization origin.