Computer analysis of current instabilities in piezoelectric semiconductors

A mathematical model is presented which describes the interaction of electrons and phonons in one-dimensional piezo-electric semiconductors. The essential features of the model considered are taken from the theory of Yamashita and Nakamura with the inclusion of both spatial and time variations. Numerical solutions of the basic equations show that the model results in damped current oscillations and a current which persists for a time after the voltage is turned off. A simplified model, which restricts the growth of the phonon density, is shown to result in undamped square wave current oscillations.