Unique Gold Nanorods Embedded Active Layer Enabling Strong Plasmonic Effect To Improve the Performance of Polymer Photovoltaic Devices

It has been widely reported that plasmonic effects of metallic nanomaterials can enhance light-harvesting in polymer solar cells (PSCs). However, the improved light trapping degree is closely related to the shape of the nanoparticles (NPs), which inevitably limits the efficiency enhancement for PSCs. In this paper, we demonstrate that the incorporation of Au arrowhead nanorods (AHNRs) into the active layer of inverted PSCs can dramatically lead to a 28.7% efficiency enhancement as compared to preoptimize control PSCs. Both theoretical and experimental results show that the origin of the improved power conversion efficiency (PCE) can be attributed to not only the optical absorption enhancement but also charge transport capacity improvement. The metal tip of AHNRs can lead to a significant enhancement of local field and long-range scattering. In addition, a wide-band absorption improvement is observed, and charge carrier mobilities increase by an order of magnitude. These results offer an effective approach to enhance the efficiency for PSCs.