Scattering times in AlGaN/GaN two-dimensional electron gas from magnetotransport measurements

摘要

The various scattering times of two-dimensional electron gas were investigated in modulation-doped Al_(0.22)Ga_(0.78)N/GaN quantum wells by means of magnetotransport measurements. The ratio of transport and quantum scattering times, τ_t/τ_q ～ 1, shows that the dominant mobility-limiting mechanisms are short-range scattering potentials. The low-field magnetoresistance shows the weak antilocalization and localization phenomenon from which the spin-orbit scattering and inelastic scattering times are obtained. The inelastic scattering time is found to follow the T~(-1) law, indicating that electron-electron scattering with small energy transfer is the dominant inelastic process.