Investigation of ZnO nanorods synthesized by a solvothermal method, using Al-doped ZnO seed films

ZnO nanorods were successfully grown on common glass substrates using a simple solvothermal method via the precursors of zinc acetate dihydrate (Zn(CH3COO)2·2H2O) and Hexamethylenetetramine (C6H12N4) with equal molar concentration at 0.01 mol/l, 0.025 mol/l, 0.05 mol/l, and 0.075 mol/l. The ZnO nanorods were characterized by X-ray diffraction (XRD), Scanning electron microscopy, UV–Vis absorption spectrophotometer and photoluminescence (PL) spectrometer. XRD results indicated that all the ZnO nanorods were preferentially grown along [0 0 0 1] direction (c-axis). With an increase of Zn(CH3COO)2·2H2O and C6H12N4 concentration, the diffraction intensity of ZnO nanorod along c-axis also increased. Scanning electron microscopy images showed that the well-faceted hexagonal ZnO nanorods were grown vertically from the common glass substrates. In addition, with the increase of Zn(CH3COO)2·2H2O and C6H12N4 concentration, the exciton band of ZnO nanorods determined by UV–Vis absorption spectra gradually became narrow and the intensity of exciton band also remarkably augmented. Photoluminescence spectra showed that with the increase of Zn(CH3COO)2·2H2O and C6H12N4 concentration, the position of emission peak of ZnO nanorod blue-shifts towards shorter wavelength in UV region and the luminescence intensity remarkably enhances in visible emission range (470–630 nm).

► The dependence of ZnO nanorod on the content of Zn(CH3COO)2·2H2O and C6H12N4 solution is reported.
► An increase of precursor solution concentration will augment ZnO nanorods in widths.
► An increase of precursor solution concentration will improve the optical property of ZnO nanorod.