title: Collective fluorescence enhancement in nanoparticle clusters.
abstract: Many nanoscale systems are known to emit light intermittently under continuous illumination. In the fluorescence of single semiconductor nanoparticles, the distributions of bright and dark periods ('on' and 'off' times) follow Lévy statistics. Although fluorescence from single-quantum dots and from macroscopic quantum dot ensembles has been studied, there has been little study of fluorescence from small ensembles. Here we show that blinking nanorods (NRs) interact with each other in a cluster, and the interactions affect the blinking statistics. The on-times in the fluorescence of a NR cluster increase dramatically; in a cluster with N NRs, the maximum on-time increases by a factor of N or more compared with the combined signal from N well-separated NRs. Our study emphasizes the use of statistical properties in identifying the collective dynamics. The scaling of this interaction-induced increase of on-times with number of NRs reveals a novel collective effect at the nanoscale.
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Siying
authors.initials: S
authors.lastname: Wang
authors.forename: Claudia
authors.initials: C
authors.lastname: Querner
authors.forename: Tali
authors.initials: T
authors.lastname: Dadosh
authors.forename: Catherine H
authors.initials: CH
authors.lastname: Crouch
authors.forename: Dmitry S
authors.initials: DS
authors.lastname: Novikov
authors.forename: Marija
authors.initials: M
authors.lastname: Drndic
mesh_terms: D005453:Fluorescence; D046529:Microscopy, Electron, Transmission; D043942:Nanotubes / Q000737:chemistry*; D012666:Semiconductors; D017655:Silicon Compounds; D013997:Time Factors; D014050:Toluene
chemical_list: D017655:Silicon Compounds; D014050:Toluene; C032734:silicon nitride