Two-Photon Photoluminescence from Hierarchical ZnO Nanostructures

GUSTAVO GRINBLAT; MARIA GABRIELA CAPELUTO; M. TIRADO; D. COMEDI; A. V. BRAGAS

ECS Transactions

The Society for solid State and electrochemical science and technology

Año: 2012 vol. 45 p. 67 - 72

1938-6737

Hierarchical ZnO nanostructures (such as nanowires, nanocombsand nanohedgehogs) were grown by means of a vapor-phasetransport technique in a tubular furnace. Silicon based substrateswere used, over which Au nanoclusters were deposited as growthcatalyzers. We study the two-photon absorption inducedphotoluminescence (TPPL) from the various ZnO nanoobjectsgrown using a micrometer sized polarised laser beam as theexcitation source. The UV region of the TPPL spectra containsvarious peaks whose different patterns depend on the type ofnanostructure and its orientation with respect to the incidentpolarization. We identify the peaks in the TPPL spectra, which arefound to be dominated by free exciton emission and their phononreplicas. For the nanocomb, however, Fabry-Perot modesoriginating from optical multiple reflections within the comb?steeth are demonstrated.