Surface Structure of Electron-Hole Drops in Germanium and Silicon.

摘要

Density functional formalism of Hehenberg and Kohn (HK) is generalized for the case of a multicomponent plasma. Using the self-consistent Kohn-Sham (KS) equations for electrons and holes and local density approximation for exchange-correlation potential, one can investigate the surface characteristics of electron-hole liquid (EHL) in six configurations of Ge and Si. These configurations are denoted by X(nu sub e; nu sub h), where X is either Ge or Si, and nu sub e and nu sub h are the number of occupied electron and hold bands, respectively. In normal Ge, i.e., Ge(4;2), the value of surface tension, sigma, is found to be .00037 erg/sq. cm. When Ge is subject to a uniform stress of about 3.5kg/sq. mm along direction, i.e., in Ge(1;2), sigma is calculated to be .00010 erg/sq. cm. Under a very large uniaxial stress on Ge, i.e., Ge(1;1), sigma is found to be a factor of twenty smaller than in Ge(4;2).