Improving the efficiency of polymer solar cells by incorporating gold nanoparticles into all polymer layers

We demonstrate efficiency improvement in polymer solar cells (PSCs) by ∼22% through incorporating Au nanoparticles (NPs) into all polymer layers. Au NPs are found to have distinct mechanisms in improving device performance when incorporated in different polymer layers. Au NPs in poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate) mainly contribute to better hole collection while Au NPs in active layer contributes to the enhanced optical absorption and more balanced charge-transport. Our theoretical result shows that the absorption enhancement at the active layer is attributed to plasmon resonances with strong near-field distributions penetrated into absorption polymers. These findings can be applied to design high-efficiency metallic NPs-incorporated PSCs.