Berlin 2005 – scientific programme
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HL: Halbleiterphysik
HL 58: Poster IIb
HL 58.41: Poster
Tuesday, March 8, 2005, 16:30–19:00, Poster TU F
Purcell effect of colloidal semiconductor nanocrystals in microcavities — •Robert M. Kraus1, Pavlos G. Lagoudakis1, Dmitry Talapin2, Andrey L. Rogach1, John M. Lupton1, Jochen Feldmann1, and Horst Weller2 — 1Lehrstuhl für Photonik und Optoelektronik, Ludwig-Maximilians-Universität München — 2Institut für Physikalische Chemie, Universität Hamburg
The theory of cavity quantum electrodynamics focuses on the fundamental questions of light matter interaction. Photon confinement in a planar microcavity geometry changes the photon mode density. An emitter embedded in the cavity has a modified spontaneous emission rate depending on its spectral and spatial overlap with the cavity mode. In our case the emitters are colloidal semiconductor nanocrystal quantum dots. Due to their polydispersity they exhibit a spectrally broad emission. A suitable resonator was built by a dielectric Bragg reflector and a silver mirror separated by a 200nm thick polymer/nanocrystal layer. By tuning the layer thickness one can choose the emission wavelength within the spectra of the nanocrystals. Q-factors of up to 300 demonstrate the excellent controllability of the fabrication process. Time resolved fluorescence decay measurements reveal an intriguing dependence of the spontaneous emission rate on temperature and Q-factor.