Electron effective masses, nonparabolicity and scattering times in one side delta-doped PHEMT AlGaAs/InGaAs/GaAs quantum wells at high electron density limit

Abstract The dependence of electron transport properties of two-dimensional electron gas on sheet doping concentration in one-sided δ-doped pseudomorphic AlxGa1-xAs/In0.2Ga0.8As/GaAs quantum wells is investigated. The wide range of silicon dopant sheet concentrations of (1.6–16) · 1012 cm-2 is investigated. Electron effective masses, nonparabolicity and scattering times are determined by low-temperature Shubnikov-de Haas effect measurements. The dependence of the quantum and transport relaxation times on nH is shown to have nonmonotonic character due to the competition of the Fermi momentum increase and the large angle scattering due to the variation of ionized donor concentration. The nonparabolicity coefficient in the In0.2Ga0.8As quantum well is determined to be 0.68 1/eV.