The full composition range CuIn(SxSe1-x)(2) alloy system has been studied using 40 mm length crystal cuts from 10 mm diameter ingots grown by the classical Bridgman method. X-ray diffraction diffractographs show that the CuIn(SxSe1-x)(2) compounds have a chalcopyrite structure for each composition x, they exhibit an expansion on the unit cell characteristics by the tetragonal distortion which depends linearly on the electronegativity of the atoms. The photoluminescence spectra is investigated as a function of various compositions, temperature and excitation intensities. Photoluminescence spectra shows a wide variation in the dominant peak location and an overall blue shift with the increase of sulphur content, Photoluminescence CuInS2 and CuIn(S0.72Se0.28)(2) have been studied in detail. (C) 2000 Elsevier Science B.V. All rights reserved.