Chapters authored
Mechanical Perturbations at the Working Electrode to Materials Synthesis by Electrodeposition
Applying mechanical perturbations at the working electrode during the electrodeposition process is a novel strategy for materials synthesis that has been used for Cu(In,Ga)Se2 (CIGS) thin film synthesis. A mechanical perturbations strategy was applied during one-step electrodeposition, and the results are compared with the traditional one-step electrodeposition where no mechanical perturbations were applied. In both cases, a potentiostatic mode was employed, where DC potential is applied to the working electrode with respect to the reference electrode; the potential is regulated by the current at an auxiliary electrode. The CIGS films obtained from both strategies were analyzed as electrodeposited and after being annealed in a selenium atmosphere. The annealed film morphology obtained with the potentiostatic mode plus periodical mechanical perturbations was denser and more compact than the film without mechanical perturbations. Using contour lines, the morphology evolution and mass transport distribution on the working electrode during the electrodeposition process are explained.
Part of the book: Perturbation Methods with Applications in Science and Engineering
Electrodeposition of Metal Chalcogenide Thin Films
Chalcogenide metals are compounds with optoelectronic characteristics that allow the construction of various optical and optoelectronic devices. The traditional preparation methods have been techniques such as reactive evaporation and sputtering. However, such methods have limited the construction of devices in large areas, particularly solar cells. Thin film solar cells based on Cu(In, Ga)Se2 (CIGSe) absorbers have suitable optoelectronic properties. However, their commercial development is scarce since the efficiencies achieved on large surfaces differ from those obtained at the laboratory level. The electrodeposition technique is the most attractive from an economic point of view; however, high conversion efficiencies still need to be achieved with the latter. Several authors attribute this difference to different causes, such as using chemical additives in the preparation. The influence of the salt during its synthesis is not studied, so this work aims to use three different types of metal salts and voltages to produce (CIGSe) absorbing thin films by the electrodeposition technique. Also, the effect of nucleation type on two other substrates is studied. The various features of structural, morphological, atomic composition, and electrochemical characterization were to understand the formation, growth, and morphology of CIGS films, to obtain a suitable stoichiometry of thin film solar cells using this absorber.
Part of the book: Thin Films