Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 16: Quantum dots and wires: Optical properties I

HL 16.1: Vortrag

Montag, 25. Februar 2008, 14:00–14:15, ER 164

Optical properties of electrically pumped CdSe quantum dot structures — •Thomas Meeser, Joachim Kalden, Kathrin Sebald, Jürgen Gutowski, Arne Gust, Carsten Kruse, and Detlef Hommel — Institute of Solid State Physics, University of Bremen, P. O. Box 330 440, 28359 Bremen, Germany

CdSe quantum dots (QDs) embedded into MgS barriers possess a high potential as active material for single photon emitters working at room temperature in the green spectral region because of the enhanced confinement of the carriers leading to an improved luminescence stability. We will present micro-electroluminescence (µ-EL) measurements on a resonant-cavity light emitting diode (RCLED) which was grown by molecular beam epitaxy containing an active region consisting of self-assembled CdSe QDs in a cavity and a distributed Bragg reflector. In this presentation we will focus on integrated µ-EL intensity measurements of the QD ensemble and single-QD emission lines in dependence on the applied voltage and sample temperature. The comparison of the results achieved for single QDs leads to an estimate of the sample temperature at the position of the active region during LED operation. In addition, we will compare these results to micro-photoluminescence measurements which were performed at the same sample position including the discussion of the change of PL characteristic by the variation of the external electric field.