Coupling electron-hole and electron-ion plasmas: Realization of an npn plasma bipolar junction phototransistor

Coupling e−–h+ and gas phase plasmas with a strong electric field across a potential barrier yields a transistor providing photosensitivity and voltage gain but also a light-emitting collector whose radiative output can be switched and modulated. This optoelectronic device relies on the correspondence between the properties of a low temperature, nonequilibrium plasma and those for the e−–h+ plasma in an n-type semiconductor. Hysteresis observed in the collector current-base current characteristics is attributed primarily to charge stored in the base, and the photogeneration of e−–h+ pairs at the base-collector junction. Extinguishing the collector plasma requires an emitter-base junction reverse bias of <1 V.