Synthesis and characteristics of large-scale ZnO rods by wet chemical method

The large-scale ZnO rods of submicrometer were prepared on the bare glass using a wet chemical method under different experimental parameters,such as the reactant concentration and the growth time.The microstructure of the ZnO rods was characterized by X-ray diffractometry(XRD) and field emission scanning electron microscopy (FESEM) with the energy dispersive X-ray spectroscopy(EDX),and the optical property was investigated by the room-temperature photoluminescence (PL) spectra.XRD and FESEM results show that the wurtzite structure and rod-like ZnO is obtained.The length (3-8 μm) and the diameter (400 nm-3 μm) vary with the experimental parameters.A strong UV emission at 384 nm and a weak visible yellow-green emission around 570 nm are observed in the PL spectrum.After annealing at 600 ℃ in air,the UV peak intensity increases obviously and the yellow-green peak intensity decreases greatly.The near-band-edge UV emission is attributed to the exciton recombination; the yellow-green emission can be associated with the defect recombination; and some defect complexes may be responsible for the latter emission.