Effect of Doping of Trimetallic Nanospheres on Optical Properties and Field Distribution in P3HT : PCBM Organic Solar Cells

Abstract

Abstract This study presents a numerical analysis of methods to enhance light absorption in P3HT : PCBM organic solar cells by adding trimetallic Ag : Au : Cu nanoparticles to the active layer. Finite-difference time-domain simulations in Lumerical, under standard illumination conditions, are used to compare the optical performance of organic solar cells (OSCs) containing trimetallic nanoparticles with those doped with monometallic Ag, Au, and Cu nanoparticles. The analysis focuses on wavelength-dependent absorbance, scattering, and absorption cross-sections, as well as near-field electric-field intensity distributions for nanoparticles with an average size of 10 nm. The results show that trimetallic Ag : Au : Cu nanoparticles exhibit superior spectral absorption and more concentrated electromagnetic fields than their single-metal counterparts. Doping with Ag : Au : Cu nanoparticles results in an average absorption enhancement of approximately 3–5% across the visible spectral region compared to the pristine device, with a maximum enhancement of approximately 11.8% near 350 nm in the near-ultraviolet region. The cross-sectional analysis shows that the improved performance comes from the combined effect of plasmonic coupling. This coupling strengthens both localised surface plasmon resonance and scattering within the active layer. The enhanced electric field intensity observed around trimetallic nanoparticles promotes significant light trapping in the active layer. The results show that incorporating heterogeneous nanoparticles at the nanoscale can achieve a moderate balance between optical and electrical properties.