The growth and physics of ultra-high-mobility two-dimensional hole gas on (311) A GaAs surface (original) (raw)

We report on the molecular beam epitaxy growth of modulation-doped GaAs-(Ga,AlMs heterostructures on the (311)A GaAs surface using silicon as the acceptor. Two-dimensional hole gases (2DHGs) with low-temperature hole mobility exceeding 1.2 X lo6 cm2 V-' s-l with carrier concentrations as low as 0.8 X 10" cmP2 have been obtained. This hole mobility is the highest ever observed at such low densities by any growth technique. We also report the first observation of persistent photoconductivity in a 2DHG. An analysis of the number density and temperature dependence of the mobility leads us to conclude that the mobility is limited by phonon scattering above u 4 K and interface scattering at lower temperatures.