Electrochemical behavior of indium tin oxide electrodes spin coated with Nafion-[Ru(bpy)3]2+ thin films

© 2015, National Institute of Optoelectronics. All right reserved. Indium tin oxide (ITO) electrodes were modified by depositing Nafion-[Ru(bpy)3]2+ thin films on the electrode surface via the spin coating technique. Scanning electron microscopy (SEM) was used to study the surface morphology of the thin films. Cyclic voltammetry (CV) was used to determine the transport mechanism and the diffusion coefficient of the redox mediators within the films. Different film thicknesses were fabricated by varying the speeds with which the spin coater thinned out the films. SEM micrographs showed a trend of increasing smoothness with increasing thinning rate. The resulting film thickness can be manipulated by simply varying the speed at which the deposited film is thinned out. CV results show successful incorporation of [Ru(bpy)3]2+ within the films. The order of the magnitude of the diffusion coefficients confirmed that the redox mediators were immobilized within the Nafion thin film.