Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 49: Nanomaterials II
MM 49.5: Vortrag
Donnerstag, 29. März 2012, 12:45–13:00, H 1029
Luminescence Properties of Cer-doped Yttrium Aluminum Garnet (YAG:Ce) Nanoparticles - Absolute Quantum Yields and Influence of Particle Size — •Martin Kaiser1, Christian Würth1, Ute Resch-Genger1, Mark Vorsthove2, and Ullrich Kynast2 — 1BAM Federal Institute for Materials Research and Testing, Berlin, Germany — 2University of Applied Sciences, Münster, Germany
Yttrium aluminum garnet (YAG) doped with Ce3+ (YAG:Ce) is a green-yellow emitting phosphor widely used in the rapidly expanding market of white light LEDs for converting the blue emission of (In,Ga)N-Chips into white. Its advantages compared to other materials include a high photostability and a high luminescence quantum yield (QY) of up to 95 %.
Here, we present measurements of the QY and luminescence lifetimes of a series of YAG:Ce particles of varying sizes ranging from 20 nm to a few micrometer using a new custom designed integrating sphere setup traceably calibrated. The ultimate goal is to understand the influence of the surface-to-volume ratio and the Ce3+ dopant concentration on the photophysical properties of these materials. Our measurements reveal that the QY and decay kinetics are clearly affected by particle size. Low temperature time-resolved measurements were performed to gain a deeper understanding of the decay kinetics.