Copper indium disulfide (CuInS2) thin films for photovoltaic applications were grown by close-spaced vapor transport in a vertical reactor closed under vacuum. Solid iodine was used to provide the reagent. Optimal deposition conditions were determined by studying samples deposited on soda-lime glass with X-rays, scanning electron microscopy, energy-dispersive spectroscopy, optical cal absorption, and Hall effect. The stoichiometry temperature range in relatively large compared to other I-III-VI compounds: the lower limit (similar to 370 degrees C) corresponds to the formation of CuI in the layers and the upper limit (similar to 680 degrees C) is imposed by the glass substrate. No phase change was observed in this temperature range. All the layers are p-type conducting, with carrier densities of the order of 10(16) cm(-3) and high mobility values in certain casts.