Analytical investigation of CdSe/CdS/ZnSe‐based single‐core double‐shell nanotextured vertical nanopillar array antenna for broadband photodetection applications

Abstract

SummaryThe photon‐trapping nanostructures greatly contributes in minimizing the light reflectance losses occurring due to air–semiconductor refractive mismatch in photodetector devices. Here we have proposed a vertically oriented CdSe/CdS/ZnSe tri material‐based multiple core–shell nanopillar array structure to act as a light‐trapping efficient antenna for broadband photodetection applications. The nanopillar structure consist of diamond shaped nanotexturization over its three layer pillar interfaces. The proposed nanotexturization over the triple‐layered nanopillar structure would feature multiple scattering mechanisms for the trapped photons enhancing their optical path length along with the defect‐free confinement of the exciton pairs. The lattice compatibility of the CdS and ZnS shell layers forms a bridge between the lattice‐mismatched CdSe core and ZnSe shell leading towards the attainment of a reduced strain as well as high photochemical stability and photo quantum efficiency. As compared to the single‐layered CdSe/ZnSe nanotextured core–shell nanopillar structure the double‐layered nanotextured CdSe/CdS/ZnSe exhibits a high photoresponsivity of 0.425 A/W and external quantum efficiency of 0.98 is attained. The obtained results exhibit that the double‐shell layered‐based nanotextured nanopillar array structure would be a well‐competent alternative as compared to the planar counterpart for next‐generation photodetector applications.