Effect of metal source variation in cuprous oxide thin films deposited by chemical bath deposition

In this study, the effect of copper source in cuprous oxide thin films deposited by chemical bath deposition is presented. The replacement of copper sulfate by copper chloride, nitrate, or acetate in proportions of 25, 50, 75, and 100% were tested. When copper chloride was used, thicker films with larger particle size, fewer structural defects, and greater preferential orientation to crystallize towards the plane (200) were obtained, which resulted in electrically resistive thin films. The opposite behavior was recorded when copper acetate was used, obtaining the films with the lowest thickness and particle size, and the greatest preferential orientation to crystallize towards the plane (111) causing them to be the most electrically conductive films, while the films deposited using copper nitrate presented properties similar to those calculated with copper acetate, but with a slightly lower electrical conductivity. It is noteworthy that the mixture of metal sources with copper sulfate encourages a greater presence of structural defects, which in turn produces an increase in electrical conductivity, a condition that is seen more clearly when 25% of copper sulfate is replaced by copper acetate or nitrate. The latter is very important since it results in a simple strategy to adjust the electrical properties to the desired values in applications such as photovoltaics, photoelectrolysis, photocatalysis, and sensor design.