Influence of deep levels on the performance of AlGaInP/GaAs heterojunctionbipolar transistor

We have studied deep levels in AlGaInP emitter of AlCaInP/GaAs heterojuncti on bipolar transistor by deep-level transient spectroscopy and photolumines cence (PL) methods. Two deep levels were obtained with thermal activation e nergies of E-c - E-t1 = 0.42 eV and E-c - E-t2 = 0.59 eV, whose capture cro ss sections are 6.27 x 10(-17) cm(2) and 6.49 x 10(-20) cm(2), where E-t1 a nd E-t2 are Si-related and O-related deep levels, respectively. The relatio nship between excitation power and PL peak intensity have revealed that non radiative recombination centers of deep levels exist in AlGaInP. The curren t gain of AlGaInP/GaAs HBT decreases due to the existence of deep levels in AlGaInP.