Novel velocity-electric field relation for modelling of compound semiconductor field-effect transistors

A novel empirical relation is proposed for the velocity-electric-field profile of compound semiconductors. The velocity-field curve in compound semiconductors (e.g. GaAs, InP etc.) has a peak which is followed by a negative-differential-resistance region in which the velocity decreases continuously with increase in the electric field. The proposed empirical fit is a two-piece nonlinear approximation, the first part being a third-order polynomial and the second part being an exponential relation to ensure the continuity and smoothness over the entire region. The accuracy of the model is confirmed by comparing and contrasting the proposed empirical curve with the available experimental and simulated results. The proposed model is expected to find useful application in analytical modelling of field-effect transistors