Spray pyrolysis deposition of Cu-Zn-In-S solid-solution thin films with tunable compositions and band gaps

Cu-Zn-In-S solid solution thin films with tunable compositions and band gaps were deposited on glass substrates using a chemical spray pyrolysis approach. XRD results reveal the cubic-structured Cu-Zn-In-S films without detectable impurities. The successive shift of XRD patterns toward high-angle side of ZnS with increasing ZnS molar fraction in products proves a formation of Cu-Zn-In-S solid solutions. SEM images and EDAX analyses demonstrate homogeneous surface morphologies and adjustable compositions of Cu-Zn-In-S films, which results in film band gaps broadly tunable from 1.54 eV to 3.61 eV. These sprayed Cu-Zn-In-S solid solution thin films may find potential uses in photovoltaics and photocatalysis.