title: Fluorescence intermittency originates from reclustering in two-dimensional organic semiconductors.
abstract: Fluorescence intermittency or blinking is observed in nearly all nanoscale fluorophores. It is characterized by universal power-law distributions in on- and off-times as well as 1/f behaviour in corresponding emission power spectral densities. Blinking, previously seen in confined zero- and one-dimensional systems has recently been documented in two-dimensional reduced graphene oxide. Here we show that unexpected blinking during graphene oxide-to-reduced graphene oxide photoreduction is attributed, in large part, to the redistribution of carbon sp2domains. This reclustering generates fluctuations in the number/size of emissive graphenic nanoclusters wherein multiscale modelling captures essential experimental aspects of reduced graphene oxide's absorption/emission trajectories, while simultaneously connecting them to the underlying photochemistry responsible for graphene oxide's reduction. These simulations thus establish causality between currently unexplained, long timescale emission intermittency in a quantum mechanical fluorophore and identifiable chemical reactions that ultimately lead to switching between on and off states.
authors.affiliation: Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Ruth
authors.affiliation: National Taiwan University, Center for Condensed Matter Sciences, National Taiwan University,, Taipei 10617, Taiwan.
authors.forename: Michitoshi
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Peter
authors.identifier: 0000-0003-0570-9169
authors.initials: P
authors.lastname: Zapol
authors.affiliation: Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Jixin
authors.initials: J
authors.lastname: Si
authors.affiliation: Max Planck Institute for the Science of Light, Erlangen, Germany.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: McDonald
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Yurii V
authors.initials: YV
authors.lastname: Morozov
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Masaru
authors.initials: M
authors.lastname: Kuno
authors.affiliation: Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Boldizsár
authors.initials: B
authors.lastname: Jankó