ZnO nanowire co-growth on SiO2 and C by carbothermal reduction and vapour advection.
Vertically aligned ZnO nanowires (NWs) were grown on Au-nanocluster-seeded amorphous SiO(2) films by the advective transport and deposition of Zn vapours obtained from the carbothermal reaction of graphite and ZnO powders. Both the NW volume and visible-to-UV photoluminescence ratio were found to be strong functions of, and hence could be tailored by, the (ZnO+C) source-SiO(2) substrate distance. We observe C flakes on the ZnO NWs/SiO(2) substrates which exhibit short NWs that developed on both sides. The SiO(2) and C substrates/NW interfaces were studied in detail to determine growth mechanisms. NWs on Au-seeded SiO(2) were promoted by a rough ZnO seed layer whose formation was catalysed by the Au clusters. In contrast, NWs grew without any seed on C. A correlation comprising three orders of magnitude between the visible-to-UV photoluminescence intensity ratio and the NW volume is found, which results from a characteristic Zn partial pressure profile that fixes both O deficiency defect concentration and growth rate.
Laboratorio de Física del Sólido, Departamento de Física, FACET, Universidad Nacional de Tucumán, Avenida Independencia 1800, 4000 Tucumán, Argentina.
N C
NC
Vega
R
R
Wallar
J
J
Caram
G
G
Grinblat
M
M
Tirado
R R
RR
LaPierre
D
D
Comedi
D002244:Carbon / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D005740:Gases / Q000737:chemistry; D006358:Hot Temperature; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010084:Oxidation-Reduction; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D015034:Zinc Oxide / Q000737:chemistry*
D005740:Gases; D046911:Macromolecular Substances; D002244:Carbon; D012822:Silicon Dioxide; D015034:Zinc Oxide