Complex hierarchical arrangements of stacked nanoplates in Al-doped ZnO

Abstract

Al-doped micro- and nanostructures have been grown by an evaporation–deposition method with a mixture of ZnS and Al_2O_3 powders as precursor. It has been found that the presence of Al is the cause of the growth of complex morphologies, as rods formed by stacks of nanoplates and other complex hierarchical structures. The role of Al in the growth process has been investigated by electron microscopy techniques. Al-rich particles in specific sites of a central rod lead to hierachical growth. Transmission electron microscopy shows that in some cases the Al-rich zones are clusters of spinel ZnAl_2O_4 nanoparticles adhered to ZnO nanorods. Al incorporation into the structures and the dopant effect on the luminescence behavior of the ZnO structures were investigated by energy dispersive spectroscopy and by cathodoluminescence.