Investigation of Hole Mobility in GaInP/(In) GaAs/GaAs p-Type Modulation Doped Heterostructures

Ga_0.51In_0.49P/(In)GaAs/GaAs heterostructure is regarded as an excellent candidate for two dimensional hole gas system as it has a large valence band offset ratio. In this paper, we report the hole mobility in GaInP/GaAs and GaInP/ In_0.20G_0.80As/GaAs p-type modulation doped heterostructures grown by gas source molecular beam epitaxy with different p-channels and doping methods. The influences of Be:GaAs cap layer, δ-doping, and strained InGaAs p-channel on hole mobility are discussed, and qualitatively explained by the ionized impurity scattering mechanism. Finally, it was shown that the improvement of hole mobility could be achieved by the δ-doping method combined with strained InGaAs channel.