Electron-phonon interaction studies in an In0.52Al0.48As/In0.53Ga0.47As/In0.52Al0.48As quantum well structure

Joule heating measurements are carried out over a wide range of temperatures on a two-dimensional electron gas fabricated in an In0.52Al0.48As/In0.53Ga0.47As/In0.52Al0.48As heterostructure system that has a 25 nm wide In0.53Ga0.47As quantum well region. The energy loss rate is observed to be an indicator of the electron-phonon coupling processes in these systems. The temperature dependence of the energy loss rate is studied from 30 mK to 30 K and points toward a possible dominant unscreened piezoelectric coupling to the acoustic modes over temperatures of 1-30 K, with boundary scattering in the ohmic contacts gaining importance at very low temperatures. The temperature decay of the energy relaxation time exhibits a T-3 behavior at high temperatures that transitions to a T at lower temperatures and tends to saturation at millikelvin levels. (C) 2003 Elsevier B.V. All rights reserved.