We report on the realization of scalable single-photon sources (SPSs) based on single site-controlled quantum dots (SCQDs) and deterministically fabricated microlenses. The fabrication process comprises the buried-stressor growth technique complemented with low-temperature in-situ electron-beam lithography for the integration of SCQDs into microlens structures with high yield and high alignment accuracy. The microlens-approach leads to a broadband enhancement of the photon-extraction efficiency of up to (21 ± 2) % and a high suppression of multi-photon events with g(2)(τ = 0) < 0.06 without background subtraction. The demonstrated combination of site-controlled growth of QDs and in-situ electron-beam lithography is relevant for arrays of efficient SPSs which can be applied in photonic quantum circuits and advanced quantum computation schemes.
@article{arxiv.1708.03512,
title = {Enhancing the photon-extraction efficiency of site-controlled quantum dots by deterministically fabricated microlenses},
author = {Arsenty Kaganskiy and Sarah Fischbach and Andre Strittmatter and Tobias Heindel and Sven Rodt and Stephan Reitzenstein},
journal= {arXiv preprint arXiv:1708.03512},
year = {2018}
}