InSb1-xNx/InSb/GaAs alloys by thermal annealing for midinfrared photodetection

InSb1-xNx alloys on GaAs substrates are prepared by molecular beam epitaxy and in situ thermal annealed at different temperatures in Sb ambience. X-ray diffraction indicates that the amount of N incorporation in Sb lattice sites is dependent on the annealing temperature. Low annealing temperature increases the N incorporation and extends the absorption to long wavelength infrared range. InSb1-xNx photoconductors operating near 10 mu m at 77 K are realized. The measured wavelengths are in good agreement with band gaps of the alloys calculated using a two-level band anticrossing model with Varshni relation. This work will benefit those working on midinfrared photodetectors. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3524228]