A large format 1k×1k focal plane array (FPA) is realized using type-II superlattice photodiodes for long wavelength infrared detection. Material growth on a 3 in. GaSb substrate exhibits a 50% cutoff wavelength of 11 μm across the entire wafer. The FPA shows excellent imaging. Noise equivalent temperature differences of 23.6 mK at 81 K and 22.5 mK at 68 K are achieved with an integration time of 0.13 ms, a 300 K background and f/4 optics. We report a dark current density of 3.3× 10-4 A cm -2 and differential resistance-area product at zero bias R 0 A of 166 ξ cm2 at 81 K, and 5.1× 10-5 A cm -2 and 1286 ξ cm2, respectively, at 68 K. The quantum efficiency obtained is 78%.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)