Ga-doped ZnO (GZO) films with a thickness of 100 nm were prepared on cyclo-olefin polymer (COP) and glass substrates at various temperatures below 100 degrees C by ion plating with direct-current arc discharge. The dependences of the characteristics of GZO films on the substrate temperature Ts were investigated. All the polycrystalline GZO films, which exhibited a high average visible transmittance of greater than 86%, were crystallized with a wurtzite structure oriented along the c-axis. The lowest resistivities of the GZO films were 5.3 x 10(-4) Omega cm on the glass substrate and 5.9 x 10(-4) Omega cm on the COP substrate. (C) 2008 Elsevier B.V. All rights reserved.