Fabrication of Sn–Se compounds on a gold electrode by electrochemical atomic layer epitaxy

The fabrication of Sn–Se compounds, at room temperature by electrochemical atomic layer epitaxy (EC-ALE) is reported. EC-ALE involves the use of surface limited reactions to form atomic layers of the elements making up a compound (Sn and Se) in a cycle. Cyclic voltammograms were used to determine approximate deposition potentials for each element. The amperometric I–t method and differential pulse anodic stripping voltammetry were used to deposit and study the processes involved in a continuous cycling deposition which were used to form thin films of the compound. Through the analysis of the I–t transients and the stripping voltammograms it is possible to establish the formation of Sn–Se compounds. Taking into account the charges involved in the I–t deposition process, a general reaction scheme that considers the formation of SnSe2, SnSe2 − x and SnSe compounds is proposed.