We report on the growth of two types of GaInAsSb detector structures by solid source molecular beam epitaxy. One structure is capped with an AlGaAsSb window layer, and the other is a conventional PIN detector. The fabrication and performance of detectors are also reported. As a result of suppression of surface recombination, the dark reverse saturate current for the detector capped with window is much lower than the other type of detector. Black body detectivity D-bb(*) of the detector with an AlGaAsSb window is 5.0 x 10(8) cm Hz(1/2)/W, and voltage responsivity R-v is 78 V/W at 300 K. For detectors without window, D-bb(*) is 5.1 x 10(8) cm Hz(1/2)/W, and R-v is 37 V/W at 300 K. Relative spectral response is also measured. The peak response wavelength is 2.19 mum at room temperature.