G 1720 (OTTO) Gallium(III) sulphide, 99.99% Cas 12024-22-5 - used in semiconductor materials, functional ceramic materials, fluorescent powder and photoelectric materials. G 1720 (OTTO) Gallium(III) sulphide, 99.99% Cas 12024-22-5 - used to prepare gallium lanthanum sulfide glass by reacting with lanthanum sulfide.