Influence of deep levels on the performance of AlGaInP/GaAs heterojunction bipolar transistor

We have studied deep levels in AlGaInP emitter of AlGaInP/GaAs heterojunction bipolar transistor by deep-level transient spectroscopy and photoluminescence (PL) methods.Two deep levels were obtained with thermal activation energies of E c -E t1 ＝0.42eV and E c -E t2 ＝0.59eV,whose capture cross sections are 6.27×10 -17 cm 2 and 6.49×10 -20 cm 2 ，where E t1 and E t2 are Si-related and O-related deep levels,respectively. The relationship between excitation power and PL peak intensity have revealed that nonradiative recombination centers of deep levels exist in AlGaInP.The current gain of AlGaInP/GaAs HBT decreases due to the existence of deep levels in AlGaInP.