title: Visible fluorescence induced by the metal semiconductor transition in composites of carbon nanotubes with noble metal nanoparticles.
abstract: We show that single-walled carbon nanotube (SWNT) bundles emit visible fluorescence in the presence of noble metal nanoparticles and nanorods in the solid state. Conductivity measurements with metallic nanotubes, isolated from pristine SWNTs, show that they become semiconducting in the presence of the metal nanoparticles. Nanoparticle binding increases the defects in the nanotube structures which is evident in the Raman spectra. The metal-semiconductor transition removes the nonradiative decay channels of the excited states enabling visible fluorescence. Nanotube structures are imaged using this emission with resolution below the classical limits.
authors.affiliation: DST Unit on Nanoscience, Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai-600 036, India.
authors.forename: Chandramouli
authors.initials: C
authors.lastname: Subramaniam
authors.forename: T S
authors.initials: TS
authors.lastname: Sreeprasad
authors.forename: T
authors.initials: T
authors.lastname: Pradeep
authors.forename: G V
authors.initials: GV
authors.lastname: Pavan Kumar
authors.forename: Chandrabhas
authors.initials: C
authors.lastname: Narayana
authors.forename: T
authors.initials: T
authors.lastname: Yajima
authors.forename: Y
authors.initials: Y
authors.lastname: Sugawara
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Takuji
authors.initials: T
authors.lastname: Ogawa
authors.forename: J
authors.initials: J
authors.lastname: Chakrabarti