Synthesis of II-VI Semiconductors Thin Films By Ecald from Citric Buffer
The free energy change involved in the compound formation is generally negative enough to produce the underpotential deposition of the metallic element on a layer of the previously deposited nonmetallic element, and vice versa. The number of cycles, which determines the thickness of the deposits, can be repeated as many times as desired to obtain deposits of practical importance. By limiting depositions to single atomic layers, no three dimensional growth is promoted and epitaxy should result.
Once the deposit is formed, the amount of the elements deposited is determined from the charge involved in their stripping. Such investigations always confirmed the stoichiometric ratio of the elements forming the compound.
The fundamental object to the method is the necessity of singling out the proper electrochemical conditions to be used, i.e. potentials, reactants, electrolytes and pH. Moreover, being the method based on surface phenomena, the electrochemical conditions are also dependent on the substrate used. Here, the first results of the electrodeposition of CdSe and ZnSe on polycrystalline gold from citric buffer are reported.
This work was supported by the Polish National Center of Science under grant 2011/01/D/ST5/05743.
1. Gregory, B.W. and J.L. Stickney, Electrochemical atomic layer epitaxy (ECALE). Journal of Electroanalytical Chemistry, 1991. 300(1-2): p. 543-561.