Single-Photon Emission from Individual Nanophotonic-Integrated Colloidal Quantum Dots

Solution-processible colloidal quantum dots (CQDs) hold great promise for realizing single-photon sources embedded into scalable quantum technology platforms. However, the high-yield integration of large numbers of individually addressable CQDs in a photonic circuit has remained an outstanding challenge. Here, we report on integrating individual colloidal core–shell QDs into a nanophotonic network that allows for excitation and efficient collection of single photons via separate waveguide channels. An iterative electron beam lithography process provides a viable method to position single emitters at predefined positions on a chip with a yield that approaches unity. Our work moves beyond the bulk optic paradigm of confocal microscopy and paves the way for supplying chip-scale quantum networks with single photons from large numbers of simultaneously controllable quantum emitters.