High operating temperature HgCdTe coupled cavity plasmonic infrared photodetectors

Increasing the operating temperature while enhancing detectivity is paramount for the advancement of HgCdTe infrared detectors. In this context, the integration of plasmonic nanostructures emerges as one of the most intriguing avenues, promising breakthroughs in infrared sensing capabilities. Multiphysics TCAD simulations of pin nanostructured focal plane photodetector arrays unveil the potential benefits of submicron absorber thicknesses, that promise detectivities more than twice as large as those provided by conventional 5μm-thick absorbers, besides enabling operating temperatures up to 260 K. Such performance increase is discussed through the combination of numerical simulations and quantum mechanical treatment based on the occupation number formalism, describing the interaction between plasmonic and optical cavity modes responsible for the spectral broadening of the optical response, allowing for good coverage of the entire mid-infrared band (λ∈[3,5]μm).