DC performance of InP/InGaAs p-n-p heterostructure-emitter bipolar transistor

The dc performance of a novel InP/InGaAs p-n-p heterostructure-emitter bipolar transistor is first demonstrated. Though the valence band discontinuity at an InP/InGaAs heterojunction is relatively large, the addition of a heavy doped as well as thin p⁺-InGaAs emitter layer between a p-InP confinement and n⁺-InGaAs base layers effectively eliminates the potential spike at emitter-base junction, lowers the emitter-collector offset voltage, and increases the barrier for electrons, simultaneously. Experimentally, a high current gain of 88 and a low offset voltage of 54 mV are achieved. To the author´s knowledge, the offset voltage of the studied device is the lowest value among of the InP/InGaAs p-n-p heterojunction bipolar transistors.