title: Spatial modulation of above-the-gap cathodoluminescence in InP nanowires.
abstract: We report the observation of light emission on wurtzite InP nanowires excited by fast electrons. The experiments were performed in a scanning transmission electron microscope using an in-house-built cathodoluminescence detector. Besides the exciton emission, at 850 nm, emission above the band gap from 400 to 800 nm was observed. In particular, this broad emission presented systematic periodic modulations indicating variations in the local excitation probability. The physical origin of the detected emission is not clear. Measurements of the spatial variation of the above-the-gap emission points to the formation of leaky cavity modes of a plasmonic nature along the nanowire length, indicating the wave nature of the excitation. We propose a phenomenological model, which fits closely the observed spatial variations.
authors.affiliation: Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil. Laboratoire de Physique des Solides, Université Paris-Sud, CNRS-UMR 8502, F-91405 Orsay, France.
authors.forename: L H G
authors.initials: LH
authors.lastname: Tizei
authors.forename: L F
authors.initials: LF
authors.lastname: Zagonel
authors.forename: M
authors.initials: M
authors.lastname: Tencé
authors.forename: O
authors.initials: O
authors.lastname: Stéphan
authors.forename: M
authors.initials: M
authors.lastname: Kociak
authors.forename: T
authors.initials: T
authors.lastname: Chiaramonte
authors.forename: D
authors.initials: D
authors.lastname: Ugarte
authors.forename: M A
authors.initials: MA
authors.lastname: Cotta
mesh_terms: D004566:Electrodes; D004583:Electrons; D007204:Indium / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods*; D008962:Models, Theoretical; D053770:Nanowires / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*
chemical_list: D010720:Phosphines; D007204:Indium; C090882:indium phosphide