Light incoupling tolerance of resonant and nonresonant metal nanostructures embedded in perovskite medium: effect of various geometries on broad spectral resonance

In this report, the surface plasmon effect of various metal nanostructures embedded in perovskite (methylammonium lead iodide) medium has been analysed for better light incoupling. Discrete dipole approximation as a numerical approach has been used to evaluate the extinction spectra and plasmon mode induced field intensity of Au, Ag and Al nanostructures (sphere, oblate spheroid, cylinder and rectangular) of an effective radii (aeff) of 30 nm. Spatial field distribution analysis primarily elucidates that the rectangular shape is more promising as the oscillating charge confinement is high at the corners. However, the oblate shape provides broad spectral enhancement among the considered shapes for the calculated polychromatic spectrum (300 nm-800 nm) due to the occurrence of both longitudinal and transverse plasmon modes. In addition, SPR peak position and the extinction magnitude of nano oblates have been discussed for varying size (5 nm-100 nm) and aspect ratio (0.1-0.9). Obtained results show the potentiality of Al nano oblates concerning broadband light trapping into perovskite material compared to Au and Ag nano oblates. This study gives an insight for the upcoming improvement of perovskite photovoltaics due to the plasmon induced light incoupling to the host medium near the band edge.