Electron–Hole Droplet Formation Kinetics in Pure Germanium

Abstract

The Pokrovskii rate equations for electron–hole droplets (EHD) are generalized by adding a term accounting for statistical droplet nucleation in a supersaturated homogeneous gas of free excitons (FE). The surface tension, which is dominant in this new term, is also used to correct the evaporation coefficient. Examples of numerical solutions show that the size and density of the EHD created are strongly affected by how fast the FE density reaches the threshold at which embryo nucleation starts. Luminescence experiments using pulsed volume excitation are reported, and are in qualitative agreement with the theoretical predictions; e.g. a maximum in FE density occurring during EHD nucleation and a delay in the build‐up of the EHD phase are observed.