Interaction of low-density 2DEG with acoustic phonons

摘要

The energy relaxation of two-dimensional electron gas (2DEG) with low density (2.2 × 10~10 cm~(-2) in selectively-doped In_0.53Ga0.47As/InP heterostructures has been studied over a range of electron temperatures 0.1 < T_e < 2 K. The Joule power of the dc current was employed for heating the electron gas, with the four terminal ac resistance of the sample used as electron thermometer We found that the interaction with a screened small-angle piezoelectric potential of the acoustic phonons dominates in the temperature range 0.1 < T_e < 0.4 K. At higher temperatures 0.5 < T_e < 1.5 K, the change of energy balance equation is associated with a gradual transition from the small-angle interaction to a quasi-elastic one. The screening of the electron--phonon interaction and the deformation potential of acoustic phonons must be taken into consideration in this temperature range. The best fit to the data was obtained with piezoelectric constant h_14 = (0.95 ±05) × 10~7 V cm~(-1) and deformation potential E_D = (6 ±1 ) eV for both temperature ranges.