Optical Simulation and Modulation of Semitransparent Organic Solar Cells with Dual Ultrathin Ag Film Transparent Electrodes

The advancement of semitransparent organic solar cells utilizing narrow bandgap donor and acceptor materials has progressed rapidly in recent years. These semitransparent devices exhibit high absorption in the near-infrared range and high transmission in the visible region, offering broad application potential. This research suggests employing dual ultrathin metal films as transparent electrodes to fabricate semitransparent photovoltaic devices. The investigation focuses on the spectral simulation and modulation of the transparent electrode structure, film thickness, optical coupling layer, and 1D photonic crystal utilizing the optical transfer matrix method. The primary goal of the integrated optical effects is to enhance the light absorption in the active layer while maintaining device visible transparency. Simulation results indicate the feasibility of a device structure consisting of Nb₂O₅/Ag/Nb₂O₅/PM6:BTP-eC9:L8-BO/MoO₃/Ag/ZnSe/Na₃AlF₆/ZnSe, achieving an expected short-circuit current density ($J_{\text{sc}}$) of 17.10 mA cm⁻², an average visible transmittance (AVT) of 50.40%, and a light utilization efficiency (LUE) of 5.49%. The incorporation of three nonperiodic dielectric layers shows the potential to further increase $J_{\text{sc}}$, AVT, and LUE to 17.40 mA cm⁻², 51.49%, and 5.71%, respectively. This study introduces a novel device structure that optimizes active layer absorption and visible transmittance, aiming to advance semitransparent photovoltaic devices.