T 1155 (OTTO) Terbium(III) iodide, puriss, 99.99% Cas 13813-40-6 - used for creating green phosphors that enable trichromatic lighting technology. T 1155 (OTTO) Terbium(III) iodide, puriss, 99.99% Cas 13813-40-6 - used as a dopant for crystalline solid-state devices and fuel cell materials.