Growth and characterization of CuGaS2, CuAlS2 and CuGa0.9Al0.1S2 single crystals

Abstract In the search for suitable chalcogenides which may be used as infrared windows at 10μm, several chalcogenides of copper, gallium and aluminum have been investigated. Single crystals of CuGaS 2 , CuAlS 2 and CuGa 0.9 Al 0.1 S 2 have been grown by chemical vapor transport using iodine as the transport agent. They all crystallize with the chalcopyrite structure. The energy gap, infrared transmission, stability in oxygen and microhardness have been measured for these compounds. CuAlS 2 has higher thermal stability and hardness than CuGaS 2 , but its IR transmission range is smaller. The IR transmission range of the 10% solid solution lies between those of the two end members; its thermal stability and optical band gap are lower than those of both end members.