Summary
Crystals were grown of copper gallium disulfide, silver gallium disulfide, and silver indium disulfide and characterized by x-ray diffraction. A small solid solution range exists for copper gallium disulfide (and probably for silver gallium disulfide, also) in which the color changes from red-orange through olive-green to black, with atendant lattice constant changes. Crystal growth was performed by iodine vapor transport, Bridgman, or in-place-recrystalization techniques. While most of the crystals were of chalcopyrite structures, AgInS2 was of wurtzite structure. A new compound was discovered: cooper dialuminum tetrasulfide, which is of spinel structure, is highly resistant to oxidation, and at least under certain conditions fluoresces green at room temperature. The most strongly fluorescent materials often seemed to be the aluminum chalcogenides which had been activated with copper impurities. (Modified author abstract).