Nonsaturating velocity-field characteristic of gallium arsenide experimentally determined from domain measurements

A new method is presented for the measurement of the average electron drift velocity as a function of the electric field (velocity-field characteristic) for semiconductor materials which exhibit bulk negative differential conductance. The characteristic is determined from capacitive probe measurements made on high-field Gunn-effect domains. This method is most applicable for values of E > 20 kV/cm, where very little information exists. The method was applied to the measurement of the velocity-field characteristic of GaAs. The characteristic found is nonsaturating and slowly decreasing up to 100 kV/cm, the maximum measured electric field. The results correlate well with the velocity-field characteristic theoretically calculated by Heinle.