We developed a functionalized solution process to fabricate films of hexagonal ZnO nanorod arrays on Si surfaces functionalized by hydrofluoric acid and Self-Assembled Monolayers. ZnO nanorod arrays, highly oriented along the (002) plane, were obtained by a hydrothermal process through the control of heterogeneous nucleation and crystal growth on substrates. The arrays showed ultraviolet lasing action with a wavelength of about 384 nm at room temperature. The simple route developed here can be applied for light-emitting devices and can provide some helpful information to control the nucleation, morphology and orientation of crystal growth in aqueous solution systems. (c) 2005 Elsevier B.V. All rights reserved.