can't read?
Gallium antimonide (GaSb) is a semiconducting compound of gallium and antimony of the III-V family. It has a lattice constant of about 0.61 nm.
GAS 459 (OTTO) Gallium antimonide wafers, n-type, <100>, diam. × thickness 76.2 mm × 625 mm Cas 12064-03-8 - used for Infrared detectors, infrared LEDs and lasers and transistors, and thermophotovoltaic systems.