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HL: Fachverband Halbleiterphysik

HL 80: II-VI-compounds other than ZnO

HL 80.3: Vortrag

Donnerstag, 14. März 2013, 12:15–12:30, H15

Towards ion beam synthesis of single CdSe nanocrystal quantum dots in a SiO₂ matrix — •Hans Moritz Mangold¹, Jörg B. Kinzel¹, Helmut Karl², Hubert J. Krenner¹, and Achim Wixforth³ — ¹Emmy Noether Group at Lehrstuhl Experimentalphysik 1, Universität Augsburg, Deutschland — ²Lehrstuhl Experimentalphysik IV, Universität Augsburg, Deutschland — ³Lehrstuhl Experimentalphysik I, Universität Augsburg, Deutschland

II-VI compound semiconductor quantum dots (QDs) are a promising class of materials for applications in optical devices in the visible spectral domain. Here we show that in addition to traditional fabrication techniques such as molecular beam epitaxy or chemical synthesis, high fluence ion-beam implantation followed by a rapid thermal annealing step, can be readily applied to synthesize CdSe nanocrystals with superior optical properties within the thermal oxide on a Si wafer. In order to confine the implantation volume we employ chromium masks with arrays of nanoscale aperture openings with diameters smaller than 250nm. We analyzed the such implanted and annealed samples by scanning electron microscopy and micro-photoluminescence spectroscopy. We observe a pronounced broadening and blue shift of the nanocrystal emission when decreasing the aperture diameter to <1000 nm. We attribute this behavior to a reduction of the mean nanocrystal size but increase of its size distribution. For the smallest aperture sizes used we observe a pronounced shell-filling behavior characteristic for single quantum dot nanoemitters.