The stoichiometry of single ternary III-V semiconductor nanowires was analyzed by Raman spectroscopy. Freestanding AlxGa1-xAs nanowires were obtained through Metal-Organic Vapor Phase Epitaxy (MOVPE) by the Vapor Liquid Solid (VLS) mechanism on GaAs substrates. The as-grown nanowires were studied with a scanning confocal Raman spectrometer (spatial resolution ca. 300 nm). They were located by Rayleigh imaging and selected for Raman measurements. The acquired spectra exhibit 2-mode behavior. The stoichiometry of individual nanowires was determined based on the frequencies of the GaAs- and AlAs-like TO and LO peaks with an accuracy of <10%. Measurements at different positions along the axis revealed variations of the composition within single nanowires. This non-uniformity indicates that the nanowires possess an internal structure.
Single AlxGa1-xAs nanowires probed by Raman spectroscopy
PRETE, Paola;PAIANO, PASQUALE;LOVERGINE, Nicola;
2010-01-01
Abstract
The stoichiometry of single ternary III-V semiconductor nanowires was analyzed by Raman spectroscopy. Freestanding AlxGa1-xAs nanowires were obtained through Metal-Organic Vapor Phase Epitaxy (MOVPE) by the Vapor Liquid Solid (VLS) mechanism on GaAs substrates. The as-grown nanowires were studied with a scanning confocal Raman spectrometer (spatial resolution ca. 300 nm). They were located by Rayleigh imaging and selected for Raman measurements. The acquired spectra exhibit 2-mode behavior. The stoichiometry of individual nanowires was determined based on the frequencies of the GaAs- and AlAs-like TO and LO peaks with an accuracy of <10%. Measurements at different positions along the axis revealed variations of the composition within single nanowires. This non-uniformity indicates that the nanowires possess an internal structure.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
