PUB - Publikationen an der Universität Bielefeld

Thin cuprous oxide films have been prepared by chemical vapor deposition (pulsed spray evaporation-chemical vapor deposition) method without post-treatment. The synthesis of cuprous oxide was produced by applying a water strategy effect. Then, the effect of water on the morphology, topology, structure, optical properties and surface composition of the obtained films has been comprehensively investigated. The results reveal that a pure phase of Cu2O was obtained. The introduction of a small quantity of water in the liquid feedstock lowers the band gap energy from 2.16 eV to 2.04 eV. This finding was mainly related to the decrease of crystallite size due to the effect of water. The topology analyses, by using atomic force microscope, also revealed that surface roughness decreases with water addition, namely more uniform covered surface. Moreover, theoretical calculations based on density functional theory method were performed to understand the adsorption and reaction behaviors of water and ethanol on the Cu2O thin film surface. Formation mechanism of the Cu2O thin film was also suggested and discussed.