The Electron Transfer Dynamics in InAs at Strong Electric Fields

Abstract

A field-velocity characteristic of InAs electrons in a strong electric field has been studied. The simulation was carried out using a technique based on the relaxation equations of the momentum conservation, energy and concentration. The features of the field-velocity characteristic are determined: the maximum and steady-state value of the drift velocity, the value of the critical field. A theoretical study of the electric field parameters influence on the dynamics of the electron transfer process in InAs under strong electric fields has been carried out. It has been defined that a pulse-like increase of the field amplitude leads to an increase of the drift velocity maximum value and a reduction in the “overshoot” duration. It is revealed that a smoothly increased field leads to a delay in transient processes. In addition, the peak value of the drift velocity decreases if the field amplitude exceeds the value corresponding to the beginning of the saturation section in the field-velocity characteristic A numerical experiment with a variation in the duration of the field pulse revealed a decrease in the peak value of the drift velocity and a decrease in the rate of relaxation processes only at a pulse duration less than the formation time of the drift velocity “overshoot”. The spatial distribution of the drift velocity is obtained, which makes it possible to estimate the average drift velocity and the distance traveled by charge carriers. An estimate of the cutoff frequency of the material is made.