title: Electroluminescence in aligned arrays of single-wall carbon nanotubes with asymmetric contacts.
abstract: High quantum efficiencies and low current thresholds are important properties for all classes of semiconductor light emitting devices (LEDs), including nanoscale emitters based on single wall carbon nanotubes (SWNTs). Among the various configurations that can be considered in SWNT LEDs, two terminal geometries with asymmetric metal contacts offer the simplest solution. In this paper, we study, experimentally and theoretically, the mechanisms of electroluminescence in devices that adopt this design and incorporate perfectly aligned, horizontal arrays of individual SWNTs. The results suggest that exciton mediated electron-hole recombination near the lower work-function contact is the dominant source of photon emission. High current thresholds for electroluminescence in these devices result from diffusion and quenching of excitons near the metal contact.
authors.affiliation: Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, United States.
authors.forename: Xu
authors.initials: X
authors.lastname: Xie
authors.forename: Ahmad E
authors.initials: AE
authors.lastname: Islam
authors.forename: Muhammad A
authors.initials: MA
authors.lastname: Wahab
authors.forename: Lina
authors.initials: L
authors.lastname: Ye
authors.forename: Xinning
authors.initials: X
authors.lastname: Ho
authors.forename: Muhammad A
authors.initials: MA
authors.lastname: Alam
authors.forename: John A
authors.initials: JA
authors.lastname: Rogers
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D008029:Lighting / Q000295:instrumentation*; D049449:Luminescence; D008839:Microelectrodes; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012666:Semiconductors
chemical_list: D037742:Nanotubes, Carbon