Electron Effective Mass and Momentum Relaxation Time in One-Sided δ-Doped PHEMT AlGaAs/InGaAs/GaAs Quantum Wells with High Electron Density

Resumo

Using the Shubnikov–de Haas effect, the dependences of electron effective mass m* and transport and quantum momentum relaxation times in Al_0.25Ga_0.75As/In_0.2Ga_0.8As/GaAs pseudomorphic quantum wells with one-sided silicon δ-doping on the electron density in the range of (1.1–2.6) × 1012 cm^–2 have been established. Nonparabolicity coefficient m* in the linear approximation was found to be 0.133m₀/eV. Both the transport and quantum momentum relaxation times depend nonmonotonically on Hall electron density nH, which is related to the competition between growth mechanisms of the Fermi momentum and the increasing contribution of large-angle scattering with increasing donor concentration.