Highly (1000) oriented ZnO films were successfully grown onto silicon substrates using a dual plasma deposition process incorporating a metal cathodic arc source and oxygen ambient. The optical properties of a series of ZnO films deposited on quartz using similar conditions were investigated using UV-visible spectrophotometry, and the effects on the band gap were investigated. The absorption of C-excitons resulting in a blue-shift of the band gap at room temperature is accentuated due to strong absorption at higher energy for light polarized (E // c) in the highly (1000) oriented ZnO film. © 2007 Elsevier B.V. All rights reserved.