Optical modelling of a GaAs/GaSb core–shell cone-topped octagonal-faced nanopillar array with periodic trapezoidal textured cut for high photon trapping efficiency

Light reflectance mitigation is the most crucial factor for achieving optimal photodetector performance. In this respect, light-trapping mechanisms based on nanostructures or microstructures such as nanopillars, nanocones and nanopyramids have emerged promising candidate reducing overall light reflectance. This because of their large effective irradiation area, multiple scattering incident increased path length rays in these nanostructures. paper proposes an optical model a GaAs/GaSb material-based vertically oriented core–shell cone-topped octagonal nanopillar structure with periodical trapezoidal nanotexturization over it to be deployed circular planar detector surface radius 50 μm. The geometric analytical investigation proposed reveals 0.999 absorbance, 0.995A/W photoresponsivity, 87% EQE at 1 μm operating wavelength.