Atomization of Reduced Graphene Oxide Ultra-thin Film for Transparent Electrode Coating

In this research, an atomization process was introduced to deposit carbon-based nanomaterials i.e. graphene oxide (GO) on 200 mm silicon wafer for high volume production of a transparent conductive electrode (TCE). An ultrasonic spray coating process was used to deposit a stable dispersion of graphene oxide in ethanol on silicon and glass substrates. The thickness of the thin films can be controlled within a nanometer-scale with the high uniformity coating process. Functionalization of GO based on thermal reduction in Rapid Thermal Process (RTP) and Plasma Enhanced Chemical Vapour Deposition (PECVD) chambers was performed to make the GO electrically conductive and optically transparent. AFM measurements revealed that the thin film thickness has a strong correlation with the number of spray passes that can be translated into spray volume. It was discovered that the thin films demonstrate a good electrical conductivity with high optical transparency in the visible light. The sheet resistance of the films can be significantly reduced by rapid thermal annealing at a high temperature of up to 1100 °C and reach 5.3 kΩ/sq with a light transmittance of 77.1% at 550 nm wavelength. This is a low-cost solution for high volume production of TCE, which have a high potential for scaling-up.