High differential resistance type-II InAs/GaSb superlattice photodiodes for the long-wavelength infrared

Type-II InAs/GaSb superlattice photodiodes with a 50% cutoff wavelength ranging from 11 to 13 mu m are presented. Optimization of diffusion limited photodiodes provided superlattice structures for improved injection efficiency in direct injection hybrid focal plane array applications. Photodiodes with a cutoff wavelength of 12.9 mu m exhibit an R(0)A of similar to 7 Omega cm(2) and a Johnson-limited detectivity of 4.03x10(10) cm Hz(1/2) W-1 operating at 77 K. Quantum efficiency measurements indicate minority carrier diffusion lengths exceeding 3 mu m. (c) 2006 American Institute of Physics.