Optimization of electrochemical aspects for epitaxial depositing nanoscale ZnSe thin films

Studies of the electrochemical optimization of ZnSe thin film deposition on polycrystalline Au substrates using electrochemical atomic layer epitaxy are reported. Electrochemical aspects were characterized by means of cyclic voltammetry, differential pulse voltammetry, and coulometry. To study the growth mechanism of the underpotential deposition in the formation of ZnSe, the effects of Zn and Se deposition potentials and a Se-stripping potential were adjusted to optimize the deposition program. The deposit, grown using the optimized program, was proved to be a single-phase ZnSe compound with a strong (220)-preferred orientation by X-ray diffraction analysis, and scanning electronic microscopy observation shows the deposit consisted of nanoscale particles with an average size about 100 nm. The right 1:1 stoichiometric ratio of Zn to Se according to the coulometry suggests that ZnSe is formed.