Effects of Substrate on the Structure,Morphology and Optical Properties of Vertically Aligned ZnO Nanorod Arrays Grown by Low-temperature CBD Method

ZnO nanorods were grown on different substrates(quartz glass,Si and ITO glass) by the wet chemical bath deposition(CBD) method at a relatively low temperature of 95℃.X-ray diffraction(XRD) and scanning electron microscope(SEM) results illustrate that the ZnO nanorod arrays with hexagonal wurtzite structure are grown densely and vertically on all the substrates,whereas the average diameter and length are found to be closely related to the substrates nature.High intensity near-band edge ultraviolet(UV) emission peak are observed in room temperature photoluminescence(PL) spectra for the ZnO nanorod arrays on all substrates,yet the usually observed defect related deep level emissions are nearly undetectable regardless of crystalline or amorphous,indicating high optical quality ZnO nanorod arrays can be achieved via this low temperature easy process chemical approach.Moreover,the small shift in the UV emission among different substrates is interpreted in terms of compress stress,which is further demonstrated by the Raman spectra measurement results.