Hierarchical ZnO nanostructures: Growth mechanisms and surface correlated photoluminescence

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

APPLIED PHYSICS LETTERS

AMER INST PHYSICS

Año: 2012 vol. 100 p. 1 - 4

0003-6951

ZnO nanowires were grown by vapor-transport and deposition on Au nanocluster covered fused andthermal silica and c-Si. The nanowire size and density depended strongly on the substrate type. Bydecreasing the O2 to local Zn partial pressure ratio, the growth pattern changed to nanocombs andnanosheets. ZnO nanohedgehogs were found on bare c-Si. We observe a remarkable correlationbetween the defect to exciton photoluminescence intensity ratio and the nanostructures specific surfaceareas. These results indicate that changes in strain and O deficiency defects at surfaces are behind theobserved morphology changes, one to two-dimensional growth transition, and correspondingluminescence.