Premium
The periodic, electrochemical codeposition of cadmium and tellurium
Author(s) -
Verbrugge M. W.,
Tobias C. W.
Publication year - 1987
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690330411
Subject(s) - tellurium , cadmium , cadmium telluride photovoltaics , chemistry , deposition (geology) , electrochemistry , diffusion , electrode , electromotive force , mass transfer , inorganic chemistry , analytical chemistry (journal) , thermodynamics , materials science , nanotechnology , chromatography , organic chemistry , paleontology , physics , quantum mechanics , sediment , biology
A mathematical model is presented for the codeposition of cadmium and tellurium onto a rotating‐disk electrode. The treatment incorporates the equation of convective diffusion for liquid phase mass transport, Butler‐Volmer expressions for charge‐transfer reactions, and a thermodynamic model for individual component activities in the solid state. Because of the formation of CdTe, a compound that has a large negative free energy of formation, the cadmium deposition reaction occurs at potentials substantially positive to its standard electrode potential ( U θ = −0.40 V). This reaction, along with the deposition of tellurium ( U θ = + 0.55 V), produces an electrodeposit that contains cadmium, tellurium, and cadmium telluride. The model can be used to calculate transient current‐potential relationships, ionic concentration profiles, and deposit compositions. Transport and kinetic parameters for cadmium and tellurium deposition are reported; a multidimensional optimization routine is used to evaluate physiochemical parameters from experimental data for the codeposition process.