Regensburg 2016 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 40: Graphene: Optics
(Joint session of DS, DY, HL, MA, O and TT organized by HL)
TT 40.3: Vortrag
Dienstag, 8. März 2016, 15:30–15:45, H17
Gate-Voltage Dependency of Förster Transfer in Graphene - Quantum Dot Photo Detection — •Lorenz Maximilian Schneider1, Ruifeng Li2, Huizhen Wu2, Martin Koch1, and Arash Rahimi-Iman1 — 1Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, 35032 Marburg, Germany — 2Department of Physics and the State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, 310058, P.R. China
Graphene photodetectors functionalized by colloidal Quantum dots (cQDs) have been recently demonstrated for effective photo detection. Nevertheless, the transfer of the energy or charge carriers from cQDs to graphene is not sufficiently understood. Here, we present a respective study of a graphene field-effect transistor, which is functionalized with CdSe/ZnS Core-Shell QDs covering it's conductive channel. In order to investigate energy transfer dynamics in this system, we have investigated the time-resolved photo-luminescence from the cQDs as function of the applied gate voltage. A clear change in the photo-luminescence lifetime has been observed, indicating a change of the decay channels. In support of our findings, we provide data for a Förster-like energy transfer model as a function of the gate voltage. The model shows that by applying a backgate voltage to the photo detector, absorbance can be tuned with respect to the photo-luminescence of the cQDs, changing the energy transfer rate of the photo-detector.