Eletrodeposição de filmes finos de óxido cuproso sobre cdtrodos de ouro

Abstract

With the growing global energy demand, and with the extremely high potential of using solar energy to supply this demand, the search for a material that is low cost and efficient in converting solar energy, has been the focus of interest for many researches. Cuprous oxide (Cu2O) is an abundant, non-toxic material that has been widely considered for use in solar cells, as it can meet the cost and efficiency prerequisites sought. In this work, thin films of Cu2O were produced, using the electrodeposition technique, which consists of the growth of a certain material, on a solid substrate, through electrochemical reactions. For electrodeposition of the films, the potentiostatic method with three electrodes was used. The substrate used was gold, with crystallographic orientation (111), acquired from easily obtainable and economically accessible recordable compact discs. The parameters of synthesis and deposition were defined based on reports already published and experiments carried out in the laboratory, with samples deposited with different deposition potentials in electrolytes of pHs close to 9, 10 and 12. In the characterization of the produced films, investigations of the morphology of the layers, using atomic force microscopy images, of the crystalline structure, using the X-ray diffractometry technique, and to identify the type of semiconductor formed and evaluate the photoelectrochemical stability, photoelectrochemical measurements were performed. The results obtained for the characterization of atomic force microscopy and X-ray diffractions, showed the formation of Cu2O thin films with good quality, uniform and with good adhesion to the substrate, with probable formation of octahedral and in transition to cubic grains, with preferential orientation of the crystals in the directions (111) and (200), depending on the pH and electrodeposition potential used.The photoelectrochemical measurements revealed the predominant presence of p-type load carriers and, considering the parameters used, most of the semiconductors produced proved to be photoelectrochemical stable. In this way, it is possible to consider Cu2O films produced, for use as energy absorption layers in solar cells formed by the junction of semiconductors of the p-n type.