RAMAN SCATTERING AND PHOTOLUMINESCENCE OF GaAs NANOWIRES
I.V. Kalachev1,2, I.A. Milekhin1,2, E.A. Emelyanov2, V.V. Preobrazhenskii2, V.S. Tumashev2, A.G. Milekhin2, A.V. Latyshev2
1Novosibirsk State University, Novosibirsk, Russia
2A.V. Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: photoluminescence, Raman scattering, near-field optical spectroscopy, nanostructures, nanowires, phonons, localized surface plasmon resonance
Abstract
The paper presents experimental data on phonon and optical properties of (111)-oriented GaAs nanowires on a gold substrate studied by means of Raman scattering and photoluminescence (PL). The structural parameters of the nanowires are determined by atomic force and scanning electron microscopy (AFM and SEM, respectively). In the micro-Raman and micro-PL spectra of a single GaAs nanowire, phonon modes of GaAs and their overtones up to the third order and an exciton photoluminescence band are observed. In the micro-PL spectra, anisotropy of the PL intensity in nanowires is revealed, and the maximum/minimum signal is observed when the polarization vector is directed along/across the wire. Nano-PL maps of a single GaAs nanowire with a spatial resolution of 20 nm are obtained, which is significantly smaller than the diffraction limit. Plasmon enhancement of the near-field exciton nano-PL in the vicinity of the metallized tip of the AFM microscope is detected.
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