Microhole array metasurface-enhanced InAs/GaSb superlattice LWIR detectors with boosted photoresponse via guided-mode resonance coupling

InAs/GaSb superlattices emerge as a competitive platform for long-wavelength infrared (LWIR) detection, featuring tailorable bandgaps and suppressed Auger recombination. Despite their advantages, InAs/GaSb superlattice-based LWIR detectors suffer from limited absorption coefficients, constraining their photoresponse efficiency. The study demonstrates a guided-mode resonance-engineered metasurface detector that overcomes this limitation through a two-dimensional microhole array architecture. By resonantly coupling incident light with guided modes, our design achieves broadband (8–12 μm) absorption enhancement in the LWIR regime. Under a reverse bias of −20 mV, the resonance-enhanced detector demonstrates 29.4 % quantum efficiency at its spectral response peak of 9.35 μm, representing a 1.32 times improvement over conventional detectors. Importantly, the metasurface integration enhances specific detectivity (3.42 × 10¹⁰ Jones) while maintaining baseline noise levels, resolving the traditional responsivity-noise trade-off. This nanophotonic engineering approach establishes a paradigm for developing high-performance superlattice infrared detectors without complex epitaxial redesign.