Performance of dual-band infrared photodetectors based on M-structure superlattices

Abstract

The mainstream dual-band photodetector structures are complex, requiring careful design of each absorption layer, making it difficult to customize according to specific requirements. We simplified the structure and proposed an alternative design, which based on the nBn barrier structure combined with the M-structure superlattice (M-SL). With the utmost consideration for lattice matching, we have enabled tailored design and arbitrary adjustment of the absorption coefficients for both detection bands and the overall absorption characteristics as needed. This manuscript presents a series of dual-band photodetectors. The performance of these devices was simulated at 77K, with quantum efficiency exceeding 22% in the MWIR band of the MWIR-LWIR detector, and normalized detectivity reaching 10^(11)cm·Hz^(1/2)/W. Quantum efficiency in the LWIR to VLWIR bands surpasses 19%, with normalized detectivity reaching 10^(11)cm·Hz^(1/2)/W.