Size control of ZnO nanorod arrays grown by metalorganic chemical vapour deposition.

The size control of vertically aligned ZnO nanorod arrays (NRAs) grown by catalyst-free metalorganic chemical vapour deposition is accomplished by changing the O/Zn precursor ratio. At a higher O/Zn precursor ratio, fat ZnO NRAs with excellent alignment are produced. In contrast, slim ZnO NRAs that are considerably less well aligned grow at a lower O/Zn precursor ratio. Irrespective of their different sizes and alignments, the individual ZnO nanorods are of a defect-free single-crystalline nature and of high optical quality, indicating that changing the precursor ratio is a promising way of fabricating size-controlled ZnO NRAs.