Aa. Verevkin et al., DIRECT MEASUREMENTS OF ENERGY RELAXATION-TIME OF ELECTRONS IN ALGAAS GAAS HETEROSTRUCTURES UNDER QUASI-EQUILIBRIUM CONDITIONS/, Surface science, 362(1-3), 1996, pp. 569-573
For the first lime, results are presented of a direct measurement of t
he energy relaxation time tau(epsilon) of 2D electrons in an AlGaAs/Ga
As heterojunction at T=1 and 5-20 K. A weak temperature dependence of
tau(epsilon) for the T>4 K range and a linear temperature dependence o
f the reciprocal of tau(epsilon) for T<4K have been observed. The line
ar dependence tau(epsilon)(-1)approximate to T in the Bloch-Gruneisen
regime is direct evidence of the predominance of the piezo-electric me
chanism of electron-phonon interaction in non-elastic electron scatter
ing processes. The values of tau(epsilon) in this regime are in very g
ood agreement with the results of the Karpus theory. At higher tempera
tures, where the deformation-potential scattering becomes noticeable,
a substantial disagreement between the experimental data and the theor
etical results is observed.