PHYSICA STATUS SOLIDI B-BASIC RESEARCH, vol.225, no.2, pp.369-377, 2001 (SCI-Expanded)
We have observed acoustic phonons, absorbed as nanosecond heat pulses directly by the two-dimensional electron gas (2DEG) of a GaAs-Al0.3Ga0.7As Modulation Doped Field Effect Transistor (MODFET) structure. The effect of phonons was to increase the electron temperature of the 2DEG and also the mobility. From a comparison with the effect of electrical heating, it was possible to determine the absolute level of the phonon power observed. Finally by comparison with data on TA and LA phonon absorption by the 2DEG, it could be concluded th:dt the deformation potential was the dominant electron-phonon coupling mechanism in GaAs.