Multicomponent Structure of an Electron-Hole Liquid in Shallow SiGe/Si Quantum Wells

Abstract

The fine structure of the emission spectrum lines is studied for a quasi-two-dimensional electronhole liquid (EHL) embedded in SiGe/Si quantum wells. It is shown that the patterns observed in the spectra of the two-particle (IR band) and four-particle (visible band) recombination can be explained by the presence of both heavy and light holes in the condensed phase. Comparison of the experimental data and calculated photoluminescence spectra of EHL allow determination of its main parameters, e.g., the equilibrium density, work function for pairs of particles, and light hole–heavy hole splitting at the G-point of the Brillouin zone for quantum wells that are 3.7–5.1% Ge.