Valley Transfer of Hot Electrons in GaAs and Related Mixed Crystals

The temperature dependence of the velocity-field characteristic in n-GaAs has been measured by microwave heating technique. The results fit well to the theory by Ruch and Fawcett. The microwave-frequency dependence of the velocity-field relation has also been investigated experimentally and compared with the large signal analysis to evaluate the coupling constant Drx between rand X valleys for intervalley phonon scattering. The value of Drx is estimated to be (4.5±0.5) X 108 e V /em; this value is in good agreement with that assumed in previous theories. In addition, the velocity-field characteristic in mixed crystals, GaSbxAst-x and lnxGat-x As, has been measured and analyzed on the basis of a simple theory.