초록 |
Lead halide perovskite materials have attracted a lot of attention in photovoltaics because of its superior properties and simple fabrication process and recently their power conversion efficiency (PCE) has achieved more than 22%. However, with the issue for non-toxic alternatives to lead, tin-based perovskite materials have risen as the most promising candidate due to their excellent optical and electrical properties. Nevertheless, intrinsic defects associated with tin vacancy reinforce the metallic nature, thereby limiting the device performance significantly. Herein, we developed strategies for highly efficient tin-based perovskite solar cells via defect engineering. Our approaches effectively reduce defect concentrations and hence the background carrier density in perovskite film. As a result, we successfully fabricated formamidinium tin halide perovskite solar cells with the best PCE of 5.5% and high reproducibility. |