No abstract

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/solr.202201095.

Cu2O is attractive as abundant and low‐cost material for energy‐related applications. This study investigated the versatile spray pyrolysis of Cu2O films from aqueous solutions. The appropriate deposition temperature and amount of copper acetate in the sprayed precursor solution was determined in order to eliminate unwanted copper oxide phases. It was shown that the addition of a reducing agent containing primary/secondary OH‐groups with suitable decomposition properties is necessary in order to obtain copper in the +I oxidation state. The influence of the pH value, determined by the addition of acetic acid to solutions containing varying reducing agents, on the structural film properties, was investigated. D‐sorbitol is for the first time proposed as suitable reducing agent to obtain compact and thick (ca. 500 nm) Cu2O films with an optical band gap of 2.3 eV.