Opposite-polarity voltage generator by hole impact ionization in a silicon bipolar transistor

A single n-p-n transistor was used to generate a negative voltage at the collector terminal when a positive voltage was applied to the emitter relative to its grounded base. It is believed that this effect was a result of hole impact ionization at field E approximately=0 at the band-edge energy maximum in the base-collector junction, and some of the electrons so created diffused and drifted to the collector, thus accounting for the otherwise unexpected negative collector potential. Possible applications of this effect are given.<>