title: Spectral focusing of broadband silver electroluminescence in nanoscopic FRET-LEDs.
abstract: Few inventions have shaped the world like the incandescent bulb. Edison used thermal radiation from ohmically heated conductors, but some noble metals also exhibit 'cold' electroluminescence in percolation films, tunnel diodes, electromigrated nanoparticle aggregates, optical antennas or scanning tunnelling microscopy. The origin of this radiation, which is spectrally broad and depends on applied bias, is controversial given the low radiative yields of electronic transitions. Nanoparticle electroluminescence is particularly intriguing because it involves localized surface-plasmon resonances with large dipole moments. Such plasmons enable very efficient non-radiative fluorescence resonance energy transfer (FRET) coupling to proximal resonant dipole transitions. Here, we demonstrate nanoscopic FRET-light-emitting diodes which exploit the opposite process, energy transfer from silver nanoparticles to exfoliated monolayers of transition-metal dichalcogenides. In diffraction-limited hotspots showing pronounced photon bunching, broadband silver electroluminescence is focused into the narrow excitonic resonance of the atomically thin overlayer. Such devices may offer alternatives to conventional nano-light-emitting diodes in on-chip optical interconnects.
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Robin P
authors.initials: RP
authors.lastname: Puchert
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Steiner
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Plechinger
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Felix J
authors.initials: FJ
authors.lastname: Hofmann
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Ines
authors.initials: I
authors.lastname: Caspers
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Johanna
authors.initials: J
authors.lastname: Kirschner
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Nagler
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Alexey
authors.initials: A
authors.lastname: Chernikov
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Schüller
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Korn
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Vogelsang
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bange
authors.affiliation: Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: John M
authors.initials: JM
authors.lastname: Lupton