Poster + Paper
13 June 2023 Broadband and high-quantum-efficiency LWIR T2SL nBn detector with guided-mode-resonance structure
Author Affiliations +
Conference Poster
For the next-generation 8 to 14μm long-wavelength infrared (LWIR) sensing, type-II superlattices (T2SLs) detectors have enormous potential to appeal to various applications including space, medical imaging, and defense. In typical absorber design, the sufficiently thick active layer (AL) is required to achieve high quantum efficiency (QE), whereas it can cause a high dark current and increase the cost. Moreover, a simple increase in AL thickness does not provide an increase in QE due to the limited carrier lifetime in T2SLs. A possible solution to the weak absorption in the AL of the T2SL-based detectors involves incorporating the AL into an optically resonant cavity. In this work, optically enhanced QE for the broadband T2SL nBn detectors will be presented through the guided-mode-resonance (GMR) structures on the top surface of the T2SL. We fabricated T2SL nBn detectors with periodic gratings on the top surface. The devices showed much-enhanced QE due to multiple resonances, as well as Fabry-Perot resonance in the thin AL with a lower dark current characteristic than the reference T2SL detector. Furthermore, we also found the broadening of the cutoff wavelength, which is typically limited by the material property, by scaling the dimension of the diffraction grating for a strong resonance beyond the cut-off region. In conclusion, the GMR-based LWIR T2SL detectors can show a significant performance enhancement in QE and extend the detection range beyond the cut-off wavelength while maintaining a low dark current.
© (2023) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Seung-yeop Ahn, Jinha Lim, Jun Ho Eom, Seong-Min Ryu, Hyun-Jin Lee, Young Ho Kim, and SangHyeon Kim "Broadband and high-quantum-efficiency LWIR T2SL nBn detector with guided-mode-resonance structure", Proc. SPIE 12534, Infrared Technology and Applications XLIX, 125341X (13 June 2023);
Get copyright permission  Get copyright permission on Copyright Marketplace
Long wavelength infrared

Quantum efficiency

Gallium antimonide

Dark current



Infrared detectors

Back to Top