Nanoscaled Multilayer Thin Films Based on GZO

Nanoscaled gallium-doped ZnO (GZO) thin films, bi-layer Pt/GZO thin films, and tri-layer GZO/Pt/GZO thin films were prepared and their characteristics were investigated. These films were deposited on glass substrates using either rf or dc magnetron sputter deposition. The deposition time and the target-to-substrate distance were varied to obtain different total film thicknesses and layer thicknesses. Effects of total film and layer thicknesses on the optical properties and the electrical properties were studied. Theoretical calculations were performed to discuss effect of the thickness on the optical transmittance of the GZO film. As-deposited GZO films show high electrical resistivity, which was greatly reduced by 2 to 3 orders of magnitude due to the introduction of a surface layer of Pt film. However, the optical transmittance was also reduced. This was improved by using an addition anti-refractive GZO surface layer on the Pt/GZO. A GZO/Pt/GZO film exhibiting visible light transmittance greater than 75% and electrical resistivity in the order of 10-4 ohm-cm was obtained.