Phase Relations in the Cu-In-S System and Growth of Large CuInS2 Single Crystals

The phase relations in the metal portion of the Cu-In-S system have been investigated by differential thermal analysis (DTA) and x-ray diffraction (XRD). The Cu-CuInS2 pseudobinary reveals a region of liquid immiscibility indicating the extension of the two liquid region from the Cu-S binary to the In-S binary. This two liquid region is intersected by two eutectics which originate at the Cu2S-In2S3 quasibinary system. In addition, the growth of large single crystals of CuInS2 have been facilitated by growth under elevated argon pressures. Growth in large temperature gradients results in a lamellar type phase, which shows good optical and electrical properties. Data from XRD, reflection high energy electron diffraction, and rocking curves are presented on the structural and morphological properties, and photoluminescence was used for a defect characterization of this material.