Structural investigations of GeS2–Ga2S3–CdS chalcogenide glasses using Raman spectroscopy

Raman investigations were carried out for various compositions of chalcogenide glasses in the GeS2–Ga2S3–CdS system. Addition of Ga2S3 into GeS2 results in the formation of metal–metal bonds and edge-shared GaS4/2 tetrahedra. Ge2+ ions may surround [GaS4/2]1− tetrahedra acting as charge compensators. Upon the addition of CdS into the GeS2–Ga2S3 system, the number of the metal–metal bonds and edge-shared GaS4/2 tetrahedra decreases, resulting in the formation of corner-shared tetrahedra with non-bridging sulfurs (NBS). Cd2+ ions can be dissolved into the glass network as charge compensators for these NBS and exited few [GaS4/2]1− tetrahedra. The high solubility of CdS is ascribed to the dissociation of metal–metal bonds and edge-shared tetrahedra in these Ga-containing glasses.