0000000000278218

AUTHOR

Anne Ponchet

showing 2 related works from this author

Splitting of surface-related phonons in Raman spectra of self-assembled GaN nanowires

2012

cited By 2; International audience; Micro Raman spectroscopy studies have been performed on GaN nanowires grown by Plasma-Assisted Molecular Beam Epitaxy on Silicon (111) substrate. From the analysis of experimental data, the emergence of a two peaks band located near 700 cm-1 has been attributed to the Raman scattering by surface-related phonons. We have analyzed the surface character of these two modes by changing the dielectric constant of the exterior medium and some experimental parameters. Furthermore, a theoretical model describing the nanowires ensemble by means of an effective dielectric function has been used to interpret the Raman scattering results. Those numerical simulations a…

Experimental parametersRaman scatteringMaterials sciencePhononNanowireGallium nitride02 engineering and technologyDielectricDielectric functions01 natural sciencessymbols.namesakechemistry.chemical_compoundCondensed Matter::Materials ScienceExperimental observation0103 physical sciencesTheoretical models010302 applied physicsSilicon (111) substrates[PHYS]Physics [physics]Condensed matter physicsNanowiresSurface phononGallium nitride021001 nanoscience & nanotechnologyCondensed Matter PhysicschemistryDielectric propertiesRaman spectroscopysymbolsPhononsPlasma-assisted molecular beam epitaxyMicro Raman Spectroscopy0210 nano-technologyRaman spectroscopyMolecular beam epitaxyRaman scatteringSurface phononMolecular beam epitaxy
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Anticrossing of axial and planar surface-related phonon modes in Raman spectra of self-assembled GaN nanowires

2012

cited By 17; International audience; GaN columnar nanostructures usually called nanowires have been investigated by micro-Raman spectroscopy. In addition to conventional Raman scattering by confined optical phonons of a wurtzite structure (i.e., E 2h and QLO modes), an unusual two peaks band centered near 700 cm -1 is observed and analyzed as a function of several experimental parameters (polarization, filling factor, incidence angle). The surface character of these two modes is experimentally confirmed by their high sensitivity to the dielectric constant of the as-grown nanowires surrounding medium. Calculations describing the nanowires' environment by means of an effective dielectric func…

Materials sciencePhononNanowirePhysics::Optics02 engineering and technologyDielectric01 natural sciencessymbols.namesakeCondensed Matter::Materials Science0103 physical sciencesSpectroscopyWurtzite crystal structure010302 applied physics[PHYS]Physics [physics]Condensed matter physicsbusiness.industryFilling factor021001 nanoscience & nanotechnologyCondensed Matter PhysicsCondensed Matter::Mesoscopic Systems and Quantum Hall EffectElectronic Optical and Magnetic MaterialssymbolsOptoelectronics0210 nano-technologybusinessRaman spectroscopyRaman scattering
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