Plasmonic enhanced mid-infrared InAs/GaSb superlattice photodetectors with the hybrid mode for wavelength-selective detection

Abstract

Photodetectors with superlattice active regions suffered from relatively low infrared absorption and thus limited responsivity, which has greatly restricted the development of mid-infrared detection technology. In this work, we theoretically demonstrate a plasmonic enhanced mid-infrared InAs/GaSb superlattice photodetector, which employs the hybrid mode not only achieving the same infrared absorption as that of the reference device at the identical resonant wavelength, but also enhancing the optical absorption at the selective wavelength. In our proposed strategy, an effective coupling of surface plasmons into electromagnetic energy in the active layer was clearly shown. Moreover, our simulation results exhibited that wavelength-selective detection is achieved by the introduction of unique metal nanostructures within the devices, which shows potential applications in infrared detection and imaging.