Intervalley scattering observed in an AlGaAs/GaAs hot-electron transistor

Electron transfer into the L and X bands of GaAs is observed in the dependence of transfer ratio α (collector current Ic/emitter current Ie) of an AlGaAs/GaAs hot-electron transistor upon emitter-base voltage Veb. The α-Veb curve and its variation with temperature change confirms the idea that electron transfer to the higher bands randomizes the electron motion and is effective in reducing α. The differential transfer ratio Δα (dIc/dIe) shows double peaks and a clear shoulder. The lower-energy peak may indicate the onset of elastic intervalley scattering.