From Ln2O2S to Ln10OS14: exploring the sulphur spectrum of trivalent lanthanoid oxysulphides

While Ln2O2S oxysulphides have increasingly gained attention due to their structural and optoelectronic properties, an expansive compositional space lies beyond as the sulphur-to-oxygen ratio increases. In these oxysulphides, the compounded effect of the 4f states is manifold in the lanthanoid ions and the changing bonding and environment symmetry enables the tuning of their electronic structure and photophysical properties. Their challenging syntheses have made these materials largely unexplored, but recent efforts have been made to bridge the knowledge gap. In this article we present some of the structural characteristics and photophysical properties of the lanthanoid oxysulphide spectrum LnxOySz.