ZnO is a Ⅱ-Ⅵ wide and direct band semiconductor. It has a large fundamental band gap of 3.37 (eV

)which makes it a promising material for use in ultraviolet light-emitting and laser diodes. Moreover

ZnO possesses a large exciton binding energy

which is much larger than that of GaN (25 meV) as well as the (thermal) excitation energy at room temperature (60 meV)

and can ensure an efficient exciton emission at room temperature. The fabrication of one-dimensional ZnO nanostructures has also been of growing interest owing to the promising application in nanoscale optoelectronic devices. ZnO nanostructures can be fabricated by various methods such as pulse laser deposition

chemical or physical vapor deposition and thermal evaporation. However

to date

for practical (application

) low-temperature growth of well-aligned ZnO nanostructures arrays which have the well-faced hexagonal structure and controlled diameters will be required. In this work

various morphologies and different sizes of ZnO rods have been fabricated through a simple chemical solution on the glass substrates by altering pH

the concentration of solution and other factors. We analyzed in detail the in-(fluence) of the pH

concentration

catalyst and temperature on the morphology of the as-grown ZnO samples. XRD patterns of all samples indicated that ZnO is a wurtzite structure and no imputity phase was found. XRD pattern of regular hexagonal ZnO rods showed that ZnO rods mainly grew along the c-axis direction. And the photoluminescence spectrum showed that there was only a near UV emission with a peak at 368 nm

and the FWHM of the emission peak is only 45 nm.