Long-wavelength type-II photodiodes operating at room temperature

The operation of uncooled InAs-GaSb superlattice photodiodes with a cutoff wavelength of /spl lambda//sub c/=8 μm and a peak detectivity of 1.2×10/sup 8/ cmHz12//W at zero bias is demonstrated. The detectivity is similar to the best uncooled HgCdTe detectors and microbolometers. However, the R0A product is more than two orders of magnitude higher than HgCdTe and the device is more than four orders of magnitude faster than microbolometers. These features combined with their low 1/f noise and high uniformity make these type-II photodiodes an excellent choice for uncooled high-speed IR imaging arrays.