文章标题/Title：
影响因子/Impact Factor：16.8
文章链接/Link：https://linkinghub.elsevier.com/retrieve/pii/S2211285525005683
摘要/Abstract：Reducing the volatile methylammonium cations (MA+) in low-bandgap tin-lead (Sn-Pb) perovskites can significantly enhance the durability of perovskite films, but at the cost of uncontrollable crystallization process and compromised device performance. Enhancing crystallization quality of perovskite films and minimizing both bulk and interface nonradiative recombination losses are crucial for improving the performance of Sn-Pb PSCs. Here, a multifunctional ionic compound, 1H-benzotriazol-1-yloxytris (dimethylamino) phosphonium hexafluorophosphate (BOP), simultaneously serves as an additive and surface passivator for MA-free Sn-Pb perovskites to enhance the device efficiency and stability. The crystallization is regulated by synergistic effects of benzotriazole (BTA) derivative groups and hexafluorophosphate anions (PF6-) on BOP, leading to high-quality Sn-Pb perovskite films with larger grains and fewer defects. The bulk doping of BOP combined with surface polishing further improves the film quality and minimizes the interfacial nonradiative recombination. Consequently, MA-free Sn-Pb PSCs without hole transport layer yield a champion efficiency of 22.23% with boosted stability. By coupling with a 1.77 eV wide-bandgap perovskite top sub cell, a four-terminal all-perovskite tandem solar cell with an efficiency of 28.45% has been achieved.
