title: Mapping charge transport by electroluminescence in chirality-selected carbon nanotube networks.
abstract: We demonstrate random network single-walled carbon nanotube (SWNT) field-effect transistors (FETs) in bottom contact/top gate geometry with only five different semiconducting nanotube species that were selected by dispersion with poly(9,9-dioctylfluorene) in toluene. These FETs are highly ambipolar with balanced hole and electron mobilities and emit near-infrared light with narrow peak widths (<40 meV) and good efficiency. We spatially resolve the electroluminescence from the channel region during a gate voltage sweep and can thus trace charge transport paths through the SWNT thin film. A shift of emission intensity to large diameter nanotubes and gate-voltage-dependent photoluminescence quenching of the different nanotube species indicates excitation transfer within the network and preferential charge accumulation on small band gap nanotubes. Apart from applications as near-infrared emitters with selectable emission wavelengths and narrow line widths, these devices will help to understand and model charge transport in realistic carbon nanotube networks.
authors.affiliation: Institute of Polymer Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Jakubka
authors.forename: Claudia
authors.initials: C
authors.lastname: Backes
authors.forename: Florentina
authors.initials: F
authors.lastname: Gannott
authors.forename: Udo
authors.initials: U
authors.lastname: Mundloch
authors.forename: Frank
authors.initials: F
authors.lastname: Hauke
authors.forename: Andreas
authors.initials: A
authors.lastname: Hirsch
authors.forename: Jana
authors.initials: J
authors.lastname: Zaumseil