InSb and InAs photovoltaic detectors cover a spectral response range equivalent to PbSe and PbS photoconductive detectors. InSb and InAs detectors, however, offer a higher response speed and better-signal-to-noise ratio and can be used in applications where PbSe and PbS detectors are not suitable. InSb photoconductive detectors are also available with a sensitivity up to around 6.5 µm, beyond the range of PbS and PbSe.