Abstract
Indium tin oxide (ITO) thin films, used in many optoelectronic applications, are typically grown to a thickness of a maximum of a few hundred nanometres. In this work, the composition, microstructure and optical/electrical properties of thick ITO coatings deposited by radio frequency magnetron sputtering from a ceramic ITO target in an Ar/O-2 gas mixture (total O-2 flow of 1%) on unheated glass substrates are reported for the first time. In contrast to the commonly observed (200) or (400) preferential orientations in ITO thin films, the approximately 3.3 mu m thick coatings display a (622) preferential orientation. The ITO coatings exhibit a purely nanocrystalline structure and show good electrical and optical properties, such as an electrical resistivity of 1.3 x 10(-1) Omega center dot cm, optical transmittance at 550 nm of similar to 60% and optical band gap of 2.9 eV. The initial results presented here are expected to provide useful information for future studies on the synthesis of high-quality thick ITO coatings.