Thermal analysis and synthesis from the melts of Cu-based quaternary compounds Cu-III-IV-VI, and Cu-2-II-IV-VI4 (II = Zn, Cd; III=Ga, In; IV=Ge, Sn ; VI=Se)

We have investigated the synthesis from the melts of Cu-III-IV-VI4 and Cu-2-II-IV-VI4 quaternary compounds (II = Zn, Cd, III = Ga, In; IV = Ge, Sn: VI = Se). Among these compounds. the single phases were obtained, except for CuGaSnSe4 and CuInSnSe4, and their melting points were determined using the differential thermal analysis. These crystal structures, and primitive optical and electrical properties of single crystals grown by the horizontal gradient freezing method from the melts, have been characterized. The CuGaGeSe4, CuInGeSe4, Cu2ZnSnSe4 and Cu2CdGeSe4 compounds are found to have band gaps suitable for optimum conversion efficiency for solar cells(1.2-1.5 eV). (C) 2000 Elsevier Science B.V. All rights reserved.