Characterization of semiconductor devices and wafer materials via sub-nanosecond time-correlated single-photon counting

Time-correlated single-photon counting (TCSPC) of semiconductor photoluminescence is presented as a versatile technique for addressing diverse aspects of charge carrier dynamics on a pico- to microsecond timescale. Particularly, advantages of expanding this time-domain technique with spectral and spatial resolution are demonstrated. By differentiating the spectral channels within the photoluminescence signal, dynamics of the charge carriers can be correlated to particular materials and substructures for analyzing their functions in complex, multicomponent systems. Diffusion and transport phenomena become directly accessible, and localized variations of charge carrier lifetimes can be associated with a particular morphology when the measurements are carried out in the context of microscopic imaging. These general capabilities are demonstrated specifi cally on a GaAsP quantum well embedded both in an AlGaAs layer structure and in a multi-layer CdTe-CdS heterojunction system.