CIGSS films prepared by sol–gel route

Homogeneous layers of amorphous oxides of Cu–In, Cu–In–Ga were deposited by a sol–gel method. Selenization, sulfurization and sequential selenization + sulfurization treatments were performed with elemental S and Se, respectively. Adherent pinhole-free layers were observed by scanning electron microscopy. X-ray diffraction indicated increased gallium incorporation in selenized in comparison with sulfurized films. Band gap values in the range of 1.18–1.63 eV were obtained.