Bottom-up approach to control the photon outcoupling of a II-VI quantum dot with a photonic wire

Epitaxially-grown semiconductor quantum dots are promising as single-photon sources due to their compatibility with manufacturing techniques and their ability to be integrated into compact devices. Efficient collection of emitted photons is required for practical use of such nano-emitters. Here, we show the possibility to form photonic wires for efficient extraction of photons by covering nanowire quantum dots with a dielectric coating using atomic layer deposition. We experimentally obtain an Al2O3-based photonic wire with a quantum dot precisely positioned along its axis. Using finite-difference time-domain (FDTD) simulations of ZnO-based photonic structures, we calculate the optimal wire geometry which leads to maximum emitted power along the wire axis. We obtain maximum values of 74% and 52% of the total emitted power for radial and a longitudinal dipoles respectively. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim