Presentation Information
[15a-PA3-21]Impact of Sulfide-Based Electron Transport Layers on the Performance of Lead-Free Cs2AgBiBr6/c-Si Tandem Solar Cells
〇(M2)TingChia Lin1, ChunYu Li1 (1.Yuntech Univ.)
Keywords:
Lead-free perovskite,Cs2AgBiBr6/Si tandem solar cells,SCAPS-1D
Lead-free double perovskite Cs2AgBiBr6 has emerged as a promising candidate for eco-friendly photovoltaic applications due to its intrinsic high stability, non-toxicity, and a wide bandgap of 1.64 eV, which is ideal for top-cell applications in tandem devices. However, the device performance is often limited by severe carrier recombination at the heterointerfaces. In this study, we utilized SCAPS-1D software to simulate and optimize the performance of Cs2AgBiBr6-based solar cells and their 2-terminal (2T) tandem application with crystalline silicon (c-Si) bottom cells. We systematically investigated four sulfide electron transport layers (ETLs) SnS2, CdS, WS2, and In2S3 to identify the optimal material for enhancing device efficiency.
Our simulation results identify SnS2 as the superior electron transport layer among the candidates tested. The device utilizing SnS2 demonstrated excellent carrier extraction capabilities, yielding a champion single-junction power conversion efficiency (PCE) of 23.56%.
Furthermore, for the tandem configuration, the filtered spectrum reaching the bottom cell was modeled using the Beer-Lambert law. We performed rigorous current matching by varying the thicknesses of the Cs2AgBiBr6 absorber (0.1–1.0 μm) and the c-Si substrate (50–300 μm). The optimal balance was achieved at a top-cell thickness of 0.583 μm and a bottom-cell thickness of 250 μm, resulting in a matched short-circuit current density (Jsc) of 21.68 mA/cm². Consequently, the optimized tandem device demonstrated remarkable performance parameters, including a Voc of 2.053 V, a fill factor of 81.08%, and a total PCE of 36.09%. These findings provide valuable design guidelines for high-efficiency lead-free perovskite/silicon tandem solar cells.
Our simulation results identify SnS2 as the superior electron transport layer among the candidates tested. The device utilizing SnS2 demonstrated excellent carrier extraction capabilities, yielding a champion single-junction power conversion efficiency (PCE) of 23.56%.
Furthermore, for the tandem configuration, the filtered spectrum reaching the bottom cell was modeled using the Beer-Lambert law. We performed rigorous current matching by varying the thicknesses of the Cs2AgBiBr6 absorber (0.1–1.0 μm) and the c-Si substrate (50–300 μm). The optimal balance was achieved at a top-cell thickness of 0.583 μm and a bottom-cell thickness of 250 μm, resulting in a matched short-circuit current density (Jsc) of 21.68 mA/cm². Consequently, the optimized tandem device demonstrated remarkable performance parameters, including a Voc of 2.053 V, a fill factor of 81.08%, and a total PCE of 36.09%. These findings provide valuable design guidelines for high-efficiency lead-free perovskite/silicon tandem solar cells.