Impurity Effects on Strain-Confined Electron-Hole Liquid in Germanium II. Millimeter-Wave Studies on Transport Phenomena

Abstract

From millimeter-wave dimensional resonance experiments, double acceptors, Be and Zn, are found to remarkably increase carrier scattering within strain-confined electron-hole liquid in Ge. Scattering rate of Be impurity is 4.2×10⁻⁴ cm³s⁻¹ both for electrons and f or holes, while that of Zn impurity is 1.0×10⁻⁴ cm³s⁻¹ for electrons and 2.3×10⁻⁴ cm³s⁻¹ for holes at 1.6 K. These values are larger than the rate for the single acceptor, In, 4.9×10⁻⁴ cm³s⁻¹. Such a result is interpreted by the Mott criterion in accordance with recombination result obtained by photoluminescence measurements. Temperature dependence of Be-induced scattering rate yields log T behavior. One possible explanation would be a kind of Kondo effect due to the atomic motion of Be impurity.