Current Saturation in n-GaAs

ABSTRACT

Electric field induced current saturation at room temperature is reported in low resistivity n-GaAs at fields much less than the threshold field for Gunn oscillations. In order to use the low resistivity crystal, surface-oriented devices were used, the fabrication technique of which is described. The apparent threshold field for the reported saturation corresponds to an electron drift velocity higher than the sound velocity in the crystal. Although no oscillation was detected, negative resistance was observed in the I-V characteristics, similar to those already observed at 77°K. Possible reasons for such saturation, based on the acoustoelectric effects in the crystal, are discussed.