Enhancing Light Absorption in the Photoactive Layer of Organic Solar Cells using Plasmonic Copper Nanorods

Bulk‐heterojunction organic solar cells have brought much interest in renewable energy due to their low cost and large‐scale fabrication. Their power conversion efficiency (PCE) suffers due to charge recombination, limiting their commercialization. In this study, the plasmonic resonance of colloidal copper nanorods (CuNRs) has been employed to enhance light absorption inside phenyl‐C 60 ‐butyric acid methyl ester: poly(3‐hexylthiophene) (P3HT:PCBM). The CuNRs with a diameter of 24.63 ± 2.1 nm and length of 53.99 ± 0.57 nm induced transverse and longitudinal absorption peaks at 450 and 680 nm, respectively, inside P3HT:PCBM. The peaks intensify with an increase in the concentration of CuNRs. Photoluminescence spectra showed an improved charge carrier lifetime for P3HT:PCBM with the incorporation of CuNRs. The CuNRs have improved the PCE of ITO/PEDOT:PSS/P3HT:PCBM:CuNRs/LiF/Al device by 34.97%. Incorporating CuNRs in P3HT:PCBM has the potential to improve the PCE of the organic solar cell by inducing plasmonic resonance.