Performance of LWIR to VLWIR barrier photodetectors based on M-structure superlattices

Antimonide superlattice materials with tunable energy bands, high electron mobility, and easy attainment of good uniformity in large-area materials, are considered to be the material of choice for third-generation infrared photodetectors. Based on energy band engineering, this paper designs a series of long-wave infrared(LWIR) to very-long-wave infrared(VLWIR) photodetectors by employing M-structure superlattice(M-SL) as both absorber layer and barrier layer. The photodetectors' performances at different temperatures are simulated in this manuscript. At 77K, while minimizing the lattice mismatch, effectively suppresses the dark current of the device which can be as low as 1× 10^-8A/cm², with a quantum efficiency reaching 20.85% and normalized detectivity achieves 4.78×10¹¹ cm·Hz^1/2/W for LWIR photodetector with a cutoff wavelength of 11.1 μm. For the VLWIR photodetector with a cutoff wavelength of 16.7 μm, the corresponding figures are 1×10^-6A/cm², 16.77% and 3.09×10¹⁰ cm·Hz^1/2/W, respectively.