Impurity centers induced by dopants in InAs/GaAs quantum-dot systems affect energy level occupation and carrier transport in multi-layer QDIPs. In order to better understand doping effects and to optimize device performance, capacitance-voltage spectra are investigated. OSIC codes: (040.3060) Infrared; (160.1890) Detector Materials; (040.5160) Photodetectors; (040.5570) Quantum detectors Multi-layer, self-assembled quantum dots (QDs) formed by the Stranski-Krastanow growth method are used as

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... active region in quantum dot infrared photodetectors (QDIPs), which are expected to have improved device performance for normal-incidence operation and high operating temperature [1] . The fundamental challenge is the non-uniformity of QD ensembles grown by strained-layer epitaxy. The resultant inhomogeneous linewidth broadening and the limited control of confined energy levels and corresponding carrier occupation precludes the rigorous design and implementation of QDIPs meeting specific requirements. It is desirable to exert more control over the QDIP spectral response and to reduce QDIP dark current by better understanding how dopants are incorporated into the energy levels of high-density QD ensembles featuring different doping schemes.