Hole-scattering mechanisms in modulation-doped heterostructures

Hole mobilities in the two highest spin-split subbands in a p-type modulation-doped heterostructure are calculated. The light-hole mobility is shown to be very low because of efficient scattering by the holes in the heavy mass subband. This finding significantly simplifies calculation of the charge transport, since only the heavy-hole contribution has to be considered. It is shown that for the state-of-the-art heterostructures the heavy-hole mobility is limited by the deformation potential acoustical and optical phonon scatterings with small contribution from ionized impurities at low temperatures. The valence-band deformation potential constant has been determined comparing the theoretical calculations with available experimental data on temperature dependence of the hole mobility.