Cu:Zn Bimetallic Nanocomposites as Plasmonic Enhancers for High‐Performance Thin Film Organic Solar Cells

Copper‐zinc bimetallic nanocomposites (Cu:Zn BMNCs) were synthesized using a wet chemistry and used as an absorber material in thin‐film organic solar cells (TFOSCs). The nanocomposites were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), and photoluminescence (PL). A traditional device architecture ITO/PEDOT:PSS/P3HT:PCBM‐Cu:Zn BMNCs/LiF/Al was used for fabrication. The pristine device, which used a P3HT: PCBM mixture, achieved a PCE of 3.22%. Additionally, adding Cu:Zn BMNCs to the photoactive layer significantly enhanced device performance. The optimal concentration of 1 wt% Cu:Zn BMNCs resulted in a PCE of 5.40%, an increase of over 68% compared to the pristine device. This improvement is attributed to better optical absorption driven by light scattering and localized surface plasmon resonance (LSPR) effects within the absorber layer, which enhances photon harvesting and charge generation. Furthermore, the experiment showed a slight increase in short‐circuit current density ( J sc ), due to improved charge carrier collection efficiency. These results demonstrate that Cu:Zn BMNCs can enhance both the optical absorption and electrical performance of TFOSCs.