title: Graphene as a Reversible and Spectrally Selective Fluorescence Quencher.
abstract: We report reversible and spectrally selective fluorescence quenching of quantum dots (QDs) placed in close proximity to graphene. Controlling interband electronic transitions of graphene via electrostatic gating greatly modifies the fluorescence lifetime and intensity of nearby QDs via blocking of the nonradiative energy transfer between QDs and graphene. Using ionic liquid (IL) based electrolyte gating, we are able to control Fermi energy of graphene in the order of 1 eV, which yields electrically controllable fluorescence quenching of QDs in the visible spectrum. Indeed, our technique enables us to perform voltage controllable spectral selectivity among quantum dots at different emission wavelengths. We anticipate that our technique will provide tunable light-matter interaction and energy transfer that could yield hybrid QDs-graphene based optoelectronic devices with novel functionalities, and additionally, may be useful as a spectroscopic ruler, for example, in bioimaging and biomolecular sensing. We propose that graphene can be used as an electrically tunable and wavelength selective fluorescence quencher.
authors.affiliation: Bilkent University, Department of Physics, 06800, Ankara, Turkey.
authors.forename: Omer
authors.initials: O
authors.lastname: Salihoglu
authors.affiliation: Bilkent University, Department of Physics, 06800, Ankara, Turkey.
authors.forename: Nurbek
authors.initials: N
authors.lastname: Kakenov
authors.affiliation: Bilkent University, Department of Physics, 06800, Ankara, Turkey.
authors.forename: Osman
authors.initials: O
authors.lastname: Balci
authors.affiliation: University of Turkish Aeronautical Association, Department of Astronautical Engineering, 06790, Ankara, Turkey.
authors.forename: Sinan
authors.initials: S
authors.lastname: Balci
authors.affiliation: Bilkent University, Department of Physics, 06800, Ankara, Turkey.
authors.forename: Coskun
authors.initials: C
authors.lastname: Kocabas