Berlin 2008 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

HL: Fachverband Halbleiterphysik

HL 31: Poster II

HL 31.42: Poster

Tuesday, February 26, 2008, 16:30–19:00, Poster D

Time-resolved electroluminescence (TREL) measurements of InAs quantum-dot spin-injection LEDs — •H. Flügge, W. Löffler, P. Aßhoff, C. Gohn, M. Hetterich, and H. Kalt — Institut für Angewandte Physik, Universität Karlsruhe (TH) and DFG Center for Functional Nanostructures, CFN, D-76128 Karlsruhe, Germany

We investigated the temporal behavior of the electro-luminescence in InAs quantum-dot spin-injection light-emitting diodes. We have recently demonstrated near-unity spin-injection fidelity in some quantum dots using a semi-magnetic spin aligner. To better understand the observed dependence of the polarization degree on emission energy we study the temporal characteristics of the polarized luminescence. In contrast to all-optical devices, where the relevant time-scale is the pico-second range, in electrical devices capacitive effects (among other things) come into play. We describe the time-correlated single-photon counting setup for the time-resolved measurements in the near infrared under pulsed current pumping. We expect the TREL technique to be able to reveal the dynamics of the relevant relaxation channels.