Thin films of copper indium disulfide (CuInS 2 ) were synthesized by spray chemical vapor deposition. Rutherford backscattering measurements were used to determine the composition and thickness of the films. The elemental ratios were found to be within 2% of stoichiometrically correct CuInS 2 . The thickness of the films was found to be approximately 1.0 μm. An optical band-gap of approximately 1.44 eV for this material was determined by optical transmission spectroscopy. Reflectance spectroscopy identified phonon bands centered at 225, 291 and 317 cm - 1 .