Optical and transport properties of InSb thin films grown on GaAs by metalorganic chemical vapor deposition (MOCVD) have been investigated by far-infrared (FIR) reflectance spectroscopy. The lattice vibration behaviors of a series of MOCVD InSb/GaAs(100) materials grown under different growth conditions were studied. Effects of III–V source ratios on the films crystalline quality were examined....