Energy loss rates of two-dimensional hole gases in inverted Si/Si[sub 0.8]Ge[sub 0.2] heterostructures.

We have investigated the energy loss rate of hot holes as a function of carrier temperature T[sub C] in p-type inverted modulation-doped (MD) Si/SiGe heterostructures over the carrier sheet density range (3.5-13)x10[sup 11] cm[sup -2], at lattice temperatures of 0.34 and 1.8 K. It is found that the energy loss rate (ELR) depends significantly upon the carrier sheet density, n[sub 2D]. Such an n[sub 2D] dependence of ELR has not been observed previously in p-type SiGe MD structures. The extracted effective mass decreases as n[sub 2D] increases, which is in agreement with recent measurements on a gated inverted sample. It is shown that the energy relaxation of the two-dimensional hole gases is dominated by unscreened acoustic phonon scattering and a deformation potential of 3.0±0.4 eV is deduced. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]