Performance-Enhancing Strategies for Wide-Bandgap Perovskite Solar Cells and Their Tandem Applications

Wide-bandgap perovskite solar cells (WBG PSCs) have emerged as critical components in the realization of high-efficiency tandem photovoltaics. With perovskite/silicon tandem cells achieving a certified power conversion efficiency of 34.9%, WBG perovskites (Eg > 1.65 eV) offer a promising route toward exceeding the Shockley–Queisser limit through enhanced spectral splitting and reduced carrier thermalization loss. However, substantial open-circuit voltage loss and photoinduced phase segregation impede WBG PSCs development. Optimization strategies targeting the composition, charge transporting layer, solvent, additives, and interface of WBG PSCs, as well as multistrategy cooperative engineering, have achieved substantial progress in overcoming these limitations. This review highlights the key performance-enhancing strategies adopted in WBG PSCs development and analyzes progress in tandem solar cells (TSCs), including perovskite/silicon, perovskite/perovskite, and perovskite/organic TSCs, as well as other perovskite-based TSCs (PBTSCs). Finally, existing bottlenecks limiting the performance of WBG PSCs and PBTSCs are critically analyzed, and potential solutions are proposed to guide future research.