Chemically Deposited CdSe Thin Films for Photoelectrochemical Cells

A chemical deposition technique has been applied to the preparation of thin CdSe films on Ti foil substrates for use in photoelectrochemical cells. The principle of the deposition process is to provide a slow generation of Cd(II) and Se -- 2 ions such that the solubility product of CdSe is just exceeded. Growth of CdSe films then occurs preferentially on surfaces with a similar crystal structure where the free energy change of nucleation is small, thereby facilitating nucleation on the substrate as opposed to nucleation in the bulk solution. The method does not require expensive capital equipment and can be scaled up to large electrode areas without problems of edge effects that are encountered in electrodeposition methods.--D.O.N.