Dresden 2017 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 44: Quantum Dots: Optical Properties II

HL 44.5: Vortrag

Dienstag, 21. März 2017, 15:45–16:00, POT 81

Ion-induced interdiffusion in self-assembled surface GaN quantum dots — •Charlotte Rothfuchs¹, Fabrice Semond², Marc Portail², Olivier Tottereau², Aimeric Courville², Andreas D. Wieck¹, and Arne Ludwig¹ — ¹Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum — ²CNRS-CRHEA, F-06560 Valbonne

In the growing field of quantum communication, there is a great demand for spin qubits and single photon sources, for which single electrically and optically active quantum dots (QDs) are prospering candidates. Providing high stability and room-temperature operation, GaN self-assembled QDs have a great appeal for these quantum technology applications. One possible pathway towards the realization of single QDs could be a top-down process using focused ion beam (FIB) implantation to post-select self-assembled molecular beam epitaxy-grown QDs. It is based on the disabling of all QDs around an intentional one by a creation of non-radiative defects. Further, magnetic impurities could be incorporated by FIB with low fluences in the non-disabled QDs for spin control. Here, we present a study on hexagonal surface GaN QDs subjected to a 100 keV gallium and a 210 keV erbium ion beam. The QDs morphology is analyzed by atomic force and scanning electron microscopy concerning their size and density. Strong diffusion processes upon ion impact at the interfaces are observed and described by a fluence-dependent model. Besides, cathodoluminescence measurements are discussed in order to investigate the ion impact on the optical properties of the QDs, influenced by the quantum confined Stark effect.