oxidesulfide

Oxidesulfide, often called oxysulfide, refers to a class of inorganic compounds in which oxide and sulfide anions coexist within a single crystal lattice. The most common stoichiometry is M2O2S, where M is a metal cation. Notable examples include yttrium oxysulfide (Y2O2S) and lanthanum oxysulfide (La2O2S). The mixed anion composition imparts chemical and physical properties distinct from those of pure oxides or sulfides.

In terms of structure, oxidesulfides exhibit a range of motifs, often related to fluorite- or layered oxide sulfide derivatives. The exact arrangement depends on the identity of M and on synthesis conditions. The presence of both oxide and sulfide sublattices influences the electronic structure, often yielding semiconducting behavior and a tunable band gap.

Synthesis typically involves high-temperature solid-state reactions among oxide and sulfide precursors or direct sulfidation of oxide lattices under reducing conditions. Many oxidesulfides are prepared in specialized laboratories and may be doped with rare-earth ions to tailor luminescent properties.

Applications are centered on luminescent materials for phosphors, particularly as hosts for Eu3+, Er3+, and other rare-earth dopants. Oxidesulfides are also studied as functional semiconductors and as potential photocatalysts, with ongoing research aimed at improving stability, optical efficiency, and synthesis scalability. Overall, oxidesulfides represent a versatile class of materials that bridge oxide and sulfide chemistries, offering opportunities in optoelectronics and energy-related applications.