Temperature-dependent surface tension of electron-hole liquid in semiconductors

Abstract
The temperature-dependent surface tension of electron-hole liquid in semiconductors is calculated using a gradient expansion of the free energy. In a noninteracting fluctuation model for electron-hole liquid-condensation, the temperature for which the surface tension vanishes provides an estimate of the critical temperature; results of the present calculation give Tc=5 K for Ge and 21.5 K for Si.