Majid Najarpour, Samiye Matloub
A novel high-efficiency dual-absorber perovskite solar cell architecture is proposed by integrating a CsPbI3 wide-bandgap top layer with an EAGeI3 narrow-bandgap bottom layer, enhanced through nanophotonic and plasmonic engineering. Using advanced three-dimensional simulations based on the Finite Element Method, the optical and electrical characteristics of the device were analyzed under realistic boundary conditions. The inclusion of EAGeI3 extends the absorption spectrum into the near-infrared region, enabling a power conversion efficiency (PCE) of 23.75%, which is 23.2% higher than the single-junction CsPbI3 structure. To improve light harvesting and carrier transport, a zigzag nanostructure was introduced at the interface between the two absorbers, raising the PCE to 24.45%. Further enhancement was achieved by embedding silver nanoparticles with cubic geometry, resulting in strong near-field plasmonic effects and efficient light scattering. The final optimized design yielded Jsc = 35.63 mA/cm2, Voc = 0.91 V, FF = 85.74%, and PCE = 27.80%, marking a 44.2% increase compared to the SJ reference and an 17% improvement over the flat dual-absorber design. Additionally, the influence of temperature variation, fabrication tolerances, and film quality on device performance was also evaluated to assess theoretical feasibility and preliminary stability. While these simulation results indicate promising potential, experimental validation is required to confirm the robustness, reproducibility, and scalability of this environmentally friendly, lead-reduced PSC.