VELOCITY-FIELD RELATION IN GAALAS VERSUS ALLOY COMPOSITION

High electric field transport in n-Ga1-xAlxAs semiconductor alloys for composition x range from 0.0 to 0.5 is studied theoretically. The calculations are based on a shifted Maxwellian approach for the three-valley conduction-band model. An expression for the alloy scattering probability involving no fitting parameters is used in these calculations. The calculations predict a close to linear decrease of peak velocity with an increase in the alloy composition x. The absence of the onset of negative differential mobility at x greater-than-or-equal-to 0.35 is found.