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.