Optical absorption and electrical properties of enhanced efficiency in organic solar cells as interfacial layer with Au NPs

Abstract The effects of the gold nanoparticles (Au NPs) on performance of organic solar cells (OSCs) are systematically investigated based on blend of the low band gap polymer and fullerene. The localized surface plasmon resonance (LSPR) induced by the Au NPs enhance the light absorption in the active layer and the photoluminescence spectra showed a significant enhancement in their intensity which mainly contribute to increased light absorption of active layer induced by LSPR. The impedance spectroscopy study revealed that the introduction of Au NPs as interfacial layer decreases the sheet and charge-transport resistance between ITO/PEDOT:PSS or PEDOT:PSS/active layer. From the results, the introduction of Au NPs increased the rate of exciton generation and the probability of exciton dissociation, thus enhancing the short-circuit current density and the fill factor The optimized OSCs incorporated with Au NPs were found to have power conversion efficiency of 5.40% compared to control device (4.65%), measured by using an AM 1.5 G solar simulator at 100 mW/cm 2 light illumination intensity.