The development of thin-film solar cells on flexible, lightweight, space-qualified durable substrates provides an attractive cost solution to fabricating solar arrays with high specific power(W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film solar cells is considered as the next generation photovoltaic devices. At NASA Glenn Research Center our group has been focused on the development of novel ternary single source precursors and the deposition of CuInS2 thin films using spray-assisted chemical vapor deposition. We investigated the effect of the film composition on texture, secondary phase formation, and grain size using XRD, SEM, and EDS and succeeded in making working devices.