Uncooled In As Sb photoconductors were fabricated. The photoconductors were based on In As0.05Sb0.95 and In As0.09Sb0.91 thick epilayers grown on In As substrates by melt epitaxy(ME). Ge immersion lenses were set on the photoconductors. The cutoff wavelength of In As0.09Sb0.91 detectors is obviously extended to 11.5 μm, and that of In As0.05Sb0.95 detectors is 8.3 μm. At room temperature, the peak detectivity of Dλp* at wavelength of 6.8 μm and modulation frequency of 1 200 Hz is 1.08×109 cm·Hz1/2·W-1 for In As0.09Sb0.91 photoconductors, the detectivity D* at wavelength of 9 μm is 7.56×108 cm·Hz1/2·W-1, and that at 11 μm is 3.92×108 cm·Hz1/2·W-1. The detectivity of In As0.09Sb0.91 detectors at the wavelengths longer than 9 μm is about one order of magnitude higher than that of In As0.05Sb0.95 detectors, which rises from the increase of arsenic(As) composition in In As0.09Sb0.91 materials. The photoconductors were based on In As0.05Sb0.95 and In As0.09Sb0.91 thick epilayers grown on In As As substrates by melt epitaxy (ME). Ge immersion lenses were set on the photoconductors. The cutoff wavelength of InAs0.09Sb 0.91 detectors is obviously extended to 11.5 μm, and that of In As0.05Sb 0.95 detectors is 8.3 μm. At room temperature, the peak detectivity of Dλp * at wavelength of 6.8 μm and modulation frequency of 1 200 Hz is 1.08 × 109 cm · Hz1 / 2 · W-1 for In As As0.09 Sb0.91 photoconductors, the detectivity D * at wavelength of 9 μm is 7.56 × 108 cm · Hz1 / 2 · W-1, and that at 11 μm is 3.92 × 108 cm · Hz1 / 2 · W-1. The detectivity of In As0.09 Sb0.91 detectors at the wavelengths longer than 9 μm is about one order of magnitude higher than that of In As0.05 Sb0.95 detectors, which rise from the increase of arsenic (As) composition in In As0.09Sb0.91 materials.