MOCVD growth of GeTe/Sb2Te3 core–shell nanowires

We report the self-assembly of core–shell GeTe/Sb2 Te3 nanowires (NWs) on Si (100), and SiO2 /Si substrates by metalorganic chemical vapour deposition, coupled to the vapour–liquid– solid mechanism, catalyzed by Au nanoparticles. Scanning electron microscopy, X-ray diffraction, micro-Raman mapping, high-resolution transmission electron microscopy, and electron energy loss spectroscopy were employed to investigate the morphology, structure, and composition of the obtained core and core–shell NWs. A single crystalline GeTe core and a polycrystalline Sb2 Te3 shell formed the NWs, having core and core–shell diameters in the range of 50–130 nm and an average length up to 7 µm.