Synthesis of well-aligned ZnO nanorods on silicon substrate at lower temperature

A facile, effective and reproducible aqueous-solution method for the synthesis of zinc oxide nanorods on pre-coated p-type silicon substrate is reported. The nanorods solution was prepared by using ammonium hydroxide as the hydroxyl precursor at a reduced temperature. By varying the seed layer solution concentration, the effect of pre-substrate treatment on the diameter, orientation and crystallinity of the asgrown ZnO nanorods were investigated. As the concentration of the seed layer solution increases, the density of the nanorods increases, the preferential orientation perpendicular to the substrate improves and the average diameter of the rods decreases. Room temperature optical spectra showed sharp UV emission and insignificant deep level emission at room temperature which confirmed the crystallinity and optical quality of the as-synthesized materials.