The main compounds are terbium trioxide, terbium dioxide, terbium trifluoride, terbium trichloride, terbium tetrafluoride and terbium (IV) salts. Terbium doped in calcium fluoride, calcium tungstate and strontium molybdate can be used to manufacture solid-state devices. Terbium oxide can be used as an activator of green phosphor for color TV picture tube and as a crystal stabilizer for fuel cell together with zirconium dioxide. Terbium sodium borate can be used as laser material. Phosphor activator.