Electron heating experiments are carried out on a two-dimensional electron gas fabricated in an In0.52Al0.48As/In0.53Ga0.47As/ln(0.52)Al(0.48)As heterostructure and the energy loss rates and energy relaxation times are extracted from the Shubnikov-de Haas oscillations to get a better understanding of the electron-phonon interaction in these heterostructures. The exponent of the energy loss rate dependence is used to indicate a dominant unscreened piezoelectric coupling in the temperature range of 4.2-30 K. Simulations of the quantum well band structure verify the presence of two populated subbands in this heterostructure system. The energy relaxation time is observed to be on the order of several tens of nanoseconds and its decay with temperature shows a T-3 behavior at higher temperatures and a T-1 behavior at lower temperatures. (C) 2003 American Vacuum Society.