Synthesis of Nano-Dimensional ZnO and Ga Doped ZnO Thin Films by Vapor Phase Transport and Study as Transparent Conducting Oxide

We report synthesis of polycrystalline ZnO and Ga doped ZnO (ZnO:Ga) thin films (∼80 nm) on Si and quartz substrates in a non-vacuum muffle furnace, a simple and cost-effective route, without any catalyst/reactive carrier gases, at relatively low processing temperature of 550 °C. The crystalline phases of the films are identified by grazing angle X-ray diffraction (GAXRD). The growth of ZnO films is examined with scanning electron microscope (SEM) as a function of deposition time. An optical transmission of ∼90% is observed for pure ZnO film having a resistivity of ∼2.1 Ω-cm as measured by van der Pauw technique. Doping with Ga results in single phase ZnO:Ga films, retaining an optical transmission of about 80% and three orders of magnitude decrease in resistivity as compared to pure ZnO film.