Evaluation of deep levels in In0.53Ga0.47As and GaAs0.5Sb0.5 using low-frequency noise and RTS noise characterization

Quantum-well photodetectors based on lattice-matched InGaAs/GaAsSb heterostructures on InP are promising candidates for mid-infrared detection. However, the dark current in these devices can be elevated by the presence of deep levels. In this work, both bulk and interfacial deep levels in MBE-grown homojunctions and heterojunctions are studied experimentally using low-frequency noise spectroscopy and random telegraph signal (RTS) characterization. Several bulk and interface-related levels have been identified and characterized in terms of energy level, cross-section and trap type. It is expected that these ongoing defect studies will enable the growth of the higher-quality material and heterostructures needed for future-generation mid-IR detectors and devices. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)