Abstract
Molecular electronic control over plasmons offers a promising route for on-chip integrated molecular plasmonic devices for information processing and computing. To move beyond the currently available technologies and to miniaturize plasmonic devices, molecular electronic plasmon sources are required. Here, we report on-chip molecular electronic plasmon sources consisting of tunnel junctions based on self-assembled monolayers sandwiched between two metallic electrodes that excite localized plasmons, and surface plasmon polaritons, with tunnelling electrons. The plasmons originate from single, diffraction-limited spots within the junctions, follow power-law distributed photon statistics, and have well-defined polarization orientations. The structure of the self-assembled monolayer and the applied bias influence the observed polarization. We also show molecular electronic control of the plasmon intensity by changing the chemical structure of the molecules and by bias-selective excitation of plasmons using molecular diodes.
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Acknowledgements
The authors acknowledge support from the National Research Foundation (NRF) under the Competitive Research Programme (CRP) (award no. NRF-CRP 8-2011-07). The authors also acknowledge NRF for supporting this research under the Prime Minister’s Office, Singapore under its Medium Sized Centre Programme. N.T. acknowledges the Institute of Materials Research and Engineering for providing financial support (grant no. IMRE/15-1P1105). H.S.C. acknowledges support from the A*STAR Computational Resource Centre through the use of its high-performance computing facilities. S.S. thanks J. Enderlein (Georg-August-Universität Göttingen) for discussions on develo** the Matlab code to calculate the defocused images from any arbitrary far-field radiation pattern.
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C.A.N. and N.T. conceived and designed the experiments. W.D. fabricated the samples. W.D. and T.W. performed the wide-field experiments and analysed the data. W.D., T.W., R.L. and N.T. performed the confocal experiments. H.S.C., L.W., S.S. and W.K.P. performed the theoretical calculations. L.J.W. synthesized S-OPE-Fc molecules. T.W., N.T. and C.A.N. wrote the manuscript. All authors discussed the results and commented on the manuscript.
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Du, W., Wang, T., Chu, HS. et al. On-chip molecular electronic plasmon sources based on self-assembled monolayer tunnel junctions. Nature Photon 10, 274–280 (2016). https://doi.org/10.1038/nphoton.2016.43
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DOI: https://doi.org/10.1038/nphoton.2016.43
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