Abstract
An experiment is described to study the carrier dynamics in an InGaAs quantum-dot-wetting-layer system emitting in the 1-/spl mu/m band at carrier densities typical of laser-diode operating conditions. The temporal evolution of the differential luminescence spectrum generated by the dots when an ultrafast optical pulse is used to perturb the steady-state carrier population of the surrounding wetting layer is measured. This provides information about the dynamic interaction of wetting-layer and quantum-dot populations. Study of the differential luminescence signal shows a marked bottleneck in the transfer of charge carriers into the quantum dots from the two-dimensional layers that surround them when the equilibrium occupancy of the dot states is high. Recovery of the system back to steady state then takes place over a time interval in excess of 600 ps. This situation arises because the dc electrical injection produces a high carrier density in the dot ensemble, and thus a high proportion of the additional photogenerated carriers remain in the wetting layer as the system thermalises. This reservoir of carriers then feeds into the dots as states are emptied by recombination events.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
