Galvanostatic anodic polarisation of Sn/SnS electrolyte system applying rapid pulse techniques

The Sn/electrodeposited SnS electrode system was anodically polarised using rapid galvanostatic rectangular pulses. Values for the layer impedance have been calculated from the observed resistance overpotential; dependence of the specific impedance on the layer thickness reveals the effect of structural changes in the semiconducting properties of the layer. It has been argued, based on the activation overpotential-current density (c.d.) relations, that the electrode kinetics are determined by reaction at the layer/solution interface, at relatively low c.d. At higher c.d., the rate-determining step is more likely the diffusion of Sn2+ through the layer, contributing appreciably higher over-potentials. Approximate values for the rate constants, k and k′, corresponding to the specific reactions determining the electrode kinetics are calculated from the corresponding kinetic parameters.