III-Sb barrier detectors suitable for the mid-wave infrared were grown on GaSb by molecular beam epitaxy. Using both bulk-InAsSb and an InAsSb-InAs strained layer superlattice, operation close to room temperature was demonstrated with cut-off wavelengths of 4.82 μm and 5.79 μm, respectively, with zero-bias operation possible for the bulk-InAsSb detector. X-ray diffraction, temperature dependent dark current and spectral quantum efficiency were measured, and an analysis based on calculated specific detectivity carried out. 1/f noise effects are considered. Results indicate these optimized devices may be suitable as alternatives to InSb, or even HgCdTe, for many applications, especially where available power is limited.