Self-induced antimony compositional variation GaAs/Ga(As)Sb core-shell nanowires by molecular beam epitaxy

Abstract

Abstract Self-catalyzed GaAs/GaAsSb heterojunction nanowires (NWs) were grown on Si (111) substrate by molecular-beam epitaxy (MBE). The GaAs/GaAsSb heterojunction NWs were determined by XRD and Raman spectra. Antimony (Sb) compositional variation of GaAs/Ga(As)Sb heterojunction NWs have been clearly evidenced by XRD spectrum, energy-dispersive X-ray (EDX) spectroscopy combined with absorption spectra. Detailed electron microscopy investigations indicate that the As-Sb exchange at the GaAsSb NWs surface during growth resulting in an outward diffusion of Sb (and corresponding inward diffusion of As), the structure of GaAs/GaAsSb/GaSb and GaAsSb/GaSb core-shell NWs were formed. This study offers a possibility to grow ternary III-V NWs with complex structures that can be used for electronic and optoelectronic applications.