INFLUENCE OF SILVER NANOPARTICLES ON TOTAL ABSORPTION FLUXES OF METHYL AMMONIUM LEAD TRI-IODIDE PHOTOCELL

Abstract

Plasmonic nanoparticles exhibit a great ability to dramatically improve photon harvesting in solar cells. They provide an exceptionally very innovative way of transforming the solar cell and photovoltaic cell industries. In photovoltaic cell research, nano-plasmonics especially noble metal nanoparticles have emerged as a new frontier runner plasmons to be incorporated in photovoltaic structures. These nano plasmons concentrate photons and channel them inside a perovskite layer. However, challenges on its effectiveness have emerged and need to be addressed. These challenges includes the loss in absorption fluxes, increased light trapping band, developing inexpensive fabrication techniques, scaling plasmonics into manufacturing levels and integrating them into perovskite active nanostructures. In this paper, we address the challenge posed by low total absorption fluxes and decreased total enhancement across the whole solar spectrum using silver nanoplasmonics to improve its total absorption fluxes. We therefore document a numerical analysis of total absorption enhancements of a model CH3NH3PbI3 perovskite photocell whose active absorber layer is embedded with spherical plasmonic silver nanoparticles of different diameters at different array spacing. It is still unknown to what extent the organic cation (framework) affects the optical and electronic properties of CH3NH3PbI3 perovskites. Further, there a number of questions that have been raised in relation to the inorganic framework or lattice though computational has suggested that CH3NH3PbI3 is influenced by different geometric parameters related to CH3NH3+ on its nitrogen K-edge (or the nitrogen 1s-orbital electrons). Therefore, new ways in which the organic cation can interact with the inorganic Pb–I lattice is believed to affect its XA spectrum and therefore its electronic structure. It has been suggested that hybridized CH3NH3+ levels in the (lead-and-iodide dominated) valence band appear to dominate in CH3NH3PbI3 crystals and the band gap in CH3NH3PbI3 can change due to the rotation of the CH3NH3+ cation, mostly by affecting the conduction band. The influence of particle size, array spacing and location is analyzed numerically and discussed in a realistic system. Results revealed that when silver nanoparticles are integrated into a CH3NH3PbI3 perovskite layer, total solar absorption enhancement increases by 8% in the infrared (IR) and by 48 % in the far-infrared (far-IR) spectra in layers of 135 nm thicknesses at minimum array spacing and maximum diameter. It was concluded that the total absorption enhancement can be improved by reinforcement from a plasmonic near-field influenced by its total cross sectional scattering effects. In this process absorption in the IR and far IR spectra is influenced in the CH3NH3PbI3 perovskite layer.