High-Field Electron Mobility In Ingaas Quantum Wells

A new approach to design the electron-optical phonon scattering rate in a quantum well (QW), based on the dependence of interface phonon frequency upon QW interface composition, is suggested. Possibilities to regulate a scattering rate of electrons by interface phonons in the In GaAs QW by selecting QW barrier materials are considered. It is shown that the electron-interface phonon scattering rate in the In0.2Ga0.8As QW can be changed by several times by choosing content x in the AlxGa1-xAs QW barriers and in the inserted InxAl1-xAs barrier in the QW centre. It is observed experimentally that the low-field mobility decreases and the high-field saturated drift velocity increases with the increase of the InyGa1-yAs/InxAl1-xAs interface phonon energy. It is shown that the electron drift velocity saturates at the electric field F > 4 kV/cm and achieves values of 1.3-1.5 x 10(7) cm/s. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim