The localized surface plasmon resonance (LSPR) effects of nanoparticles (NPs) are effective for enhancing the power conversion efficiency (PCE) of organic solar cells (OSCs). In this study, spiky durian-shaped Au@Ag core-shell NPs were synthesized and embedded in the hole transport layer (HTL) (poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS)) of PTB7:PC71BM bulk-heterojunction OSCs. Different volume ratios of PEDOT:PSS-to-Au@Ag NPs (8%, 10%, 12%, 14%, and 16%) were prepared to optimize synthesis conditions for increased efficiency. The size properties and surface morphology of the NPs and HTL were analyzed using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). UV-Vis spectroscopy and current density-voltage (J-V) analysis were used to investigate the electrical performance of the fabricated OSCs. From the results, we observed that the OSC with a volume ratio of 14% (PEDOT:PSS-to-Au@Ag NPs) performed better than others, where the PCE was improved from 2.50% to 4.15%, which is a 66% increase compared to the device without NPs.
Keywords: Au@Ag NPs; LSPR; concentration ratio NPs; organic solar cell; plasmonic effect.