Pushing the high energy limits of plasmonics

We studied the plasmonic response of oxide-free Al nanoparticles, arranged in densely-packed 2-dimensional arrays on the surface of insulating LiF crystals. The NPs exhibit a broadband plasmonic response in the deep-ultraviolet region of the EM spectrum, peaking at an energy of 6.8 eV, the highest ever reported for a LSP resonance observed by optical excitation of metallic nanoparticles. F. Bisio et al, ACS Nano, 8,9, 9239-9247 (2014)

The localized surface plasmon resonance of metal nanoparticles allows confining the eletromagnetic field in nanosized volumes, creating high-field "hot spots", most useful for enhanced nonlinear optical spectroscopies. The commonly-employed metals, Au and Ag, yield plasmon resonances only spanning the visible/near-infrared range. Stretching upwards the useful energy range of plasmonics requires exploiting different materials. Deep-ultraviolet plasmon resonances happen to be achievable with one of the cheapest and most abundant materials available: aluminum holds indeed the promise of a broadly-tunable plasmonic response, theoretically extending far into the deep-ultraviolet. Complex nanofabrication issues and the unavoidable Al oxidation have so far prevented the achievement of this ultimate high-energy response. A nanofabrication technique producing purely-metallic Al nanoparticles has at last allowed to overcome these limits, pushing the plasmon resonance to 6.8 eV photon energy and thus significantly broadening the spectral range of plasmonics’ numerous applications.


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Pushing the high energy limits of plasmonics, Francesco Bisio, Remo Proietti Zaccaria, Riccardo Moroni, Giulia Maidecchi, Alessandro Alabastri, Grazia Gonella, Angelo Giglia, Laura Andolfi, Stefano Nannarone, Lorenzo Mattera, and Maurizio Canepa , F. Bisio et al, ACS Nano, 8,9, 9239-9247 (2014)

Last Updated on Wednesday, 01 October 2014 09:38