Preparation and characterization of Cu(In,Ga)(Se,S)2 thin films from electrodeposited precursors for hydrogen production

Semiconducting Cu(In,Ga)(Se,S)2 thin films were made from electrodeposited Cu(In,Ga)Se2 precursors, followed by physical vapor deposition of In2S3, Ga, and Se. The bandgaps of these materials were found to be between 1.6 and 2.0 eV, which spans the optimal bandgap necessary for application for the top junction in photovoltaic multijunction devices and for unassisted water photolysis. These films were characterized by electron-probe microanalysis, scanning Auger spectroscopy, X-ray diffraction, and photocurrent spectroscopy.