TY - JOUR
T1 - Fabrication of coaxial nanowire heterostructures
T2 - SiOx nanowires with conformal TiO 2 coatings
AU - Shalav, Avi
AU - Venkatachalam, Dinesh K.
AU - Elliman, Robert G.
PY - 2012/6
Y1 - 2012/6
N2 - Silica nanowires, grown via the active oxidation of a silicon substrate, have been coated with TiO 2 using two coating methods: solution-based deposition of Ti-alkoxides and atomic layer deposition. Analysis of as-deposited and annealed films shows that it is possible to produce stable conformal coatings of either the anatase or rutile phases of TiO 2 on nanowires with diameters greater than 100 nm when annealed between 500-600°C and 800-900°C, respectively, with annealing at higher temperatures (1050°C) producing coatings with a highly facetted rutile morphology. The efficacy of the process is shown to depend on nanowire diameter, with nanowires having diameters less than about 100 nm fusing together during solution-based coating and decomposing during TiO 2 atomic layer deposition. The use of a suitable buffer layer is shown to be an effective means of minimizing nanowire decomposition. Finally, annealing coated nanowires under active oxidation conditions (1100°C) is shown to be an effective technique for depositing additional conformal SiO x coatings, thereby providing a means of fabricating multi-layered coaxial nanostructures.
AB - Silica nanowires, grown via the active oxidation of a silicon substrate, have been coated with TiO 2 using two coating methods: solution-based deposition of Ti-alkoxides and atomic layer deposition. Analysis of as-deposited and annealed films shows that it is possible to produce stable conformal coatings of either the anatase or rutile phases of TiO 2 on nanowires with diameters greater than 100 nm when annealed between 500-600°C and 800-900°C, respectively, with annealing at higher temperatures (1050°C) producing coatings with a highly facetted rutile morphology. The efficacy of the process is shown to depend on nanowire diameter, with nanowires having diameters less than about 100 nm fusing together during solution-based coating and decomposing during TiO 2 atomic layer deposition. The use of a suitable buffer layer is shown to be an effective means of minimizing nanowire decomposition. Finally, annealing coated nanowires under active oxidation conditions (1100°C) is shown to be an effective technique for depositing additional conformal SiO x coatings, thereby providing a means of fabricating multi-layered coaxial nanostructures.
UR - http://www.scopus.com/inward/record.url?scp=84861573858&partnerID=8YFLogxK
U2 - 10.1007/s00339-012-6804-y
DO - 10.1007/s00339-012-6804-y
M3 - Article
SN - 0947-8396
VL - 107
SP - 749
EP - 754
JO - Applied Physics A: Materials Science and Processing
JF - Applied Physics A: Materials Science and Processing
IS - 3
ER -