Nonionic polymer poly (vinylpyrrolidone) (PVP) was firstly mixed into oxygenated zinc chloride electrolyte to modulate the crystal growth and morphology of ZnO from elect rodeposition. Arrays of ZnO hexagonal prisms with well-defined (0 0 0 1) end facets and {1 0 1 0} side facets were grown perpendicularly onto p-type Si substrates using the simple and economic route. It was observed that the concentration of PVP played an important role in the final morphology and size of ZnO crystals. The optical studies indicated that the addition of PVT not only influenced crystal growth habit but also improved the optical properties of ZnO. (c) 2006 Elsevier B.V. All rights reserved.