Double heterojunction NpN GaAlAs/GaAs bipolar transistor

Double heterojunction NpN Ga0.7Al0.3As/GaAsAs/Ga0.7Al0.3-As bipolar transistors have been developed and tested. Besides a wide-gap emitter a wide-gap collector was added to form the NpN double heterojunction structure, which can be operated as a bipolar transistor in bidirection. I/V measurements show that the turn-on voltage of about 0.2 V, which is the normal case in Npn wide-gap emitter GaAsAs/Ga0.7Al0.3As transistors (common emitter), is eliminated. As compared with the Npn GaAs transistor the storage time ts of the NpN GaAs transistor is reduced by a factor of about 2.