Raman spectroscopy of core-shell GaAs-AlGaAs nanowires on Si substrates
Abstract
Gold-catalyzed GaAs-AlGaAs core-shell nanowires (NWs) were grown on Si(100) and Si(111) substrates using molecular beam epitaxy (MBE) via vapor-liquid-solid (VLS) technique. The gold deposition time was varied which effectively vary the density of the nanowires. The NWs were characterized using Raman spectroscopy. By getting the GaAs LO/TO phonon ratios of the nanowire, the effect of increasing the Au deposition time on the crystallinity of the NWs was determined. A relation was found between the Au deposition time and crystal quality of the nanowires on Si(100) while the inverse is true for nanowires on Si(111).