The intermediate solid solution, gamma-phase, exists in the CuInSe2+2CdS double left right arrow CuInS2+2CdSe reciprocal system. It crystallizes in the cubic structure and has a wide homogeneity range. Single crystals of the gamma-phase are grown by a modified Bridgman method and their composition, crystal structure, optical and electrical properties are studied. The band gap varies from 1.43 to 1.05 eV along the 'Cu3Cd2In3S8'-'CuCd2InSe4' compositional section. The crystals are photosensitive, mostly p-type, with hole concentrations in the 10(15)-10(16) cm(-3) range and mobilities Up to 18 cm(2)/Vs. The results indicate that the gamma-phase can be considered as a new absorbing material for thin-film solar cells. (c) 2008 Elsevier B.V. All rights reserved.