title: GHz Electroluminescence Modulation in Nanoscale Subwavelength Emitters.
abstract: We investigate light emission from nanoscale point-sources obtained in hybrid metal-GaAs nanowires embedding two sharp axial Schottky barriers. Devices are obtained via the formation of Ni-rich metallic alloy regions in the nanostructure body thanks to a technique of controlled thermal annealing of Ni/Au electrodes. In agreement with recent findings, visible-light electroluminescence can be observed upon suitable voltage biasing of the junctions. We investigate the time-resolved emission properties of our devices and demonstrate an electrical modulation of light generation up to 1 GHz. We explore different drive configurations and discuss the intrinsic bottlenecks of the present device architecture. Our results demonstrate a novel technique for the realization of fast subwavelength light sources with possible applications in sensing and microscopy beyond the diffraction limit.
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza San Silvestro 12, I-56127 Pisa, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Rossella
authors.affiliation: Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia , Piazza San Silvestro 12, 56127 Pisa, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Piazza
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza San Silvestro 12, I-56127 Pisa, Italy.
authors.forename: Mirko
authors.initials: M
authors.lastname: Rocci
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza San Silvestro 12, I-56127 Pisa, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Ercolani
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza San Silvestro 12, I-56127 Pisa, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Sorba
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza San Silvestro 12, I-56127 Pisa, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Beltram
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza San Silvestro 12, I-56127 Pisa, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Roddaro
keywords: GHz modulation; Schottky barrier; Subwavelength emitters; electroluminescence; optoelectronics; semiconductor nanowires