Electrodeposition of PbS Multilayers on AG(111) by ECALE (Electrochemical Atomic Layer Epitaxy)

Abstract

Lead sulfide (PbS) thin films were grown on single crystal Ag(111) substrate. PbS films were obtained by Electrochemical Atomic Layer Epitaxy (ECALE) method, that is by alternated underpotential deposition (UPD) of lead and sulfur. The voltammetric analysis of the first PbUPD and SUPD peaks indicates a mechanism of two-dimensional growth, which is consistent with epitaxial growth. Electrochemical stripping measurements indicate that amount of Pb and S deposited in a given number of cycles is a function of the number of cycles employed, again suggesting a layer-by-layer growth. The stripping charges associated with each layer of Pb and S was 87 μC cm-2. This result suggests that amount of Pb and S in these films corresponds to the stoichiometric 1:1 ratio, indicating the formation of a compound.