DC characteristics of MOVPE-grown N <i>pn</i> InGaP/InGaAsN DHBTs

Abstract

The authors have demonstrated, for the first time, a functional Npn double heterojunction bipolar transistor using a novel material, InGaAsN, with a bandgap energy of 1.2 eV as the p-type base layer. A 300 Å thick InxGa1-xAs graded layer was introduced to reduce the conduction band offset at the p-type InGaAsN base and n-type GaAs collector junction. For an emitter size of 500 µm2, a peak current gain of 5.3 has been achieved.