抄録
A new class of instability caused by the combination of heavily injected minority carriers and special geometrical shape of specimen has been observed. Current-voltage characteristics and the dependence of Hall voltage on the current show that the high density electron-hole cloud is produced in the specimen. Experimental results also show that the local high electric field region or abrupt change in the electric field strength along the specimen is indispensable for getting the instability. Coherent oscillation has been observed with application of high electric field, oscillation frequency ranging from 400 kc to 1 mc. The effect of magnetic field, both longitudinal and transverse, is to suppress the oscillation, which can be attributed to the enhanced recombination of carriers at the surface. Some tentative models for the understanding of the mechanism of the oscillation are give with brief discussions.
