INVESTIGADORES
COMEDI David Mario
artículos
Título:
ZnO nanowire co-growth on SiO2 and C by carbothermal reduction and vapour advection
Autor/es:
N. C. VEGA ; R. WALLAR; J. CARAM; G. GRINBLAT; M. TIRADO; R.R. LAPIERRE; D. COMEDI
Revista:
NANOTECHNOLOGY
Editorial:
IOP PUBLISHING LTD
Referencias:
Lugar: Londres; Año: 2012 vol. 23 p. 275602 - 275613
ISSN:
0957-4484
Resumen:
Vertically aligned ZnO nanowires (NWs) were grown on Au-nanocluster-seeded amorphous SiO2
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) sourceSiO2 substrate distance. We observe C flakes on the ZnO NWs/SiO2 substrates which exhibit short NWs that developed on both sides. The SiO2 and C substrates/NW interfaces were studied in detail to determine growth mechanisms. NWs on Au-seeded SiO2
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.