The effects of temperature on current–potential profiles from electrochemical film production: A theoretical approach

In this paper we improve an equation that describes the current–potential curves obtained during electrochemical deposition of metals on n-silicon. The equation give us the theoretical description of the voltammograms and was previously introduced in terms of the ion concentration and the potential, however it still requires the inclusion of factors that describe the influence of the temperature. Temperature controls the diffusion constant D, the electrical resistivity of the electrolytic solution ρ, and the conduction electron density on the electrode surface N. In this paper we take explicitly into account the dependence of D, ρ and N on the temperature and succeeded to relate them to a defined reaction rate k. To complete the description, we considered that the influence of the temperature could be accounted by renormalizing the magnitude of the potential that triggers the deposition. Thus, a final expression for the current I, as a function of voltage V, ion concentration cb and temperature T is achieved and a qualitative comparison between theoretical and experimental data is made. Through the comparisons, we show that the temperature affects the magnitude of the stationary currents, the amplitude of the nucleation loops and the intensity of diffusion-limited growth peak, producing a shift of the current–voltage curves toward less negative values of V. The same description allowed us to observe similar effects in the current transients.