Fig. 1. (a) Cross-sectional view of the PB₁nB₂N structure of a type-II superlattice photodetector on InAs substrate; (b) The simulated energy band diagram and electric field of the device at 77 K under zero bias

Fig. 2. Test results of InAs/GaSb superlattice materials. (a) High-resolution X-ray diffraction; (b) Atomic Force Microscopy (AFM)

Fig. 3. (a) Cross-section of the hard mask; (b) Mesa morphology

Fig. 4. Superlattice detector chip

Fig. 5. Dark current density test results of the superlattice device. （a） Unit device; (b) Focal plane array

Fig. 6. Superlattice detector assembly

Fig. 7. Test results of the superlattice focal plane detector

Fig. 8. Imaging of the long-wave superlattice focal plane detector