Ytterbium(III) sulfide is a binary inorganic compound of ytterbium and sulfur with the chemical formula . It is a yellow solid of rhombic symmetry, and cell parameters a = 0.678 nm, b = 0.995 nm, c = 0.361 nm.
Ytterbium(III) sulfide can be produced by treating metallic ytterbium with sulfur:
Once prepared, ytterbium(III) sulfide can be purified by chemical vapor transport using iodine.
Ytterbium(III) sulfide can also be prepared by treating the sulfate with hydrogen sulfide at elevated temperatures: