Berlin 2015 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 43: P8: Nanoparticles and Compsite Materials
CPP 43.26: Poster
Wednesday, March 18, 2015, 10:00–13:00, Poster A
Energy transfer characteristics of Mn doped CdS/ZnS quantum dots — Uwe Kaiser1, •Mikko Wilhelm1, Johannes Röder1, Nadeem Sabir1, Lorenz Maximilian Schneider1, Pablo del Pino2, Carolina Carrillo-Carrion1, Wolfgang Parak1, and Wolfram Heimbrodt1 — 1Department of Physics, Philipps University Marburg, Germany — 2CIC Biomagune, San Sebastian, Spain
Core shell CdS/ZnS quantum dots (QDs) doped with manganese in the ZnS shell are investigated. Photoluminescence spectra show the successful doping of the ZnS shell by the identification of the typical Mn luminescence band around 580nm. Time resolved measurements confirm this additionally by determination of the long lifetime (2ms) for this spin forbidden transition. By doping the CdS/ZnS QDs we obtain a system with two very distinct luminescence bands around 450nm from the CdS core and around 580nm from the manganese ions. The energy transfer between these two luminescence centers is not only determined by the spectral position of both bands but additionally by the interface between CdS and ZnS within the QD. The results lead furthermore to the conclusion that the low energetic Mn state cannot only act as acceptor for the high energetic CdS transition, but vice versa also as donor. This leads to an enhanced CdS lifetime from hundreds of ns without Mn to several ms in the case of Mn doping. Measurements of Mn doped QDs and QDs additionally functionalized by dye molecules also show a lifetime of the dye in the ms range, due to energy transfer from the excited Mn.