THE EFFECT OF THE SULFUR PRESSURE ON THE GROWTH OF CULNS2 SINGLE-CRYSTALS BY THE GRADIENT FREEZE TECHNIQUE

CuInS2 single crystals of moderate size have been produced by the grad ient freeze technique under different sulfur pressures. Results from e nergy dispersive x-ray (EDX) microprobe analysis show that with higher sulfur pressures the cracking along the ingot decreases, but at 2 bar these cracks are still present. X-ray diffraction shows that CuS is p resent as a minor phase. EDX analyses along the ingot show that this p hase corresponds to the cracks where In2S is released into the gas pha se. Despite this loss of In2S photoluminescence reveals the bulk mater ial to be In-rich.