Interfacial dye diffusion

Abstract

We demonstrated the (merbromin dye) diffusion into the TiO2/Au interface in order to investigate the interface boundary dye concentration profile. The diffusion system used is FTO/TiO2/Au. By using different Au thickness for the substrate, we have successfully shown that a thicker Au layer is required to eliminate dye diffusion from the Au-Au grain boundaries so that the data collected is a more accurate representative of dye diffusion in the interface region. We found out that by increasing the Au thickness, the diffusant flux approaches zero as the concentration becomes uniform. In short, this work shows that interfacial dye diffusion follows the Fisher’s model. The study enable us to investigate on how changing Au thickness can affect the dye diffusion into the TiO2/Au interface and this information will be useful for future electrolyte-less dye-sensitized solar cells (ELDSC) applications.