Self-assembly of solid or tubular ZnO rods into twinning microprisms via a hydrothermal route

The self-assembly of solid or tubular ZnO microrods into hexagonal twinning microprisms were achieved by choosing different solvents under a simple hydrothermal route. The composed solid or tubular ZnO microrods, as self-assembly building blocks, are single crystals with the [0 0 0 1] growth crystallographic direction; and most of them have diameters of similar to 2.8 mu m, lengths of up to similar to 4.6 mu m. Room-temperature photoluminescence spectrum of the solid ZnO microstructures reveals a strong emission band located at 397 nm and two broad emission bands at about 485 nm, 528 nm, respectively. A possible growth mechanism has been proposed. It is expected that the present ZnO microstructures have some potential applications in optoelectronic devices. (C) 2008 Elsevier B.V. All rights reserved.