InSb 1 − x N x / InSb / GaAs alloys by thermal annealing for midinfrared photodetection

InSb 1 − x N x 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 μm 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.