A semiconductor light-emitting transistor device, including: a bipolar pnp transistor structure having a p-type collector, an n-type base, and a p-type emitter; a first tunnel junction coupled with the collector, and a second tunnel junction coupled with the emitter; and a collector contact coupled with...http://www.google.es/patents/US7888199?utm_source=gb-gplus-sharePatente US7888199 - PNP light emitting transistor and method
