Large opening circuit voltage (V_oc) loss and poor moisture stability have significantly hindered the progress of inorganic perovskite solar cells (IPSCs). Here, we report a dual-protection strategy via incorporating monomer trimethylolpropane triacrylate (TMTA) into CsPbI₂Br perovskite bulk and capping the surface with 2-thiophenemethylammonium iodide (Th−NI) to ameliorate the above issues. Benefiting from growth control and effective suppression of both bulk and surface recombination, the resulting devices show a great improved efficiency from 12.17 to 15.58% with a champion V_oc of 1.286 V. Also, the dual-protection strategy endows films with promoted moisture tolerance, and the nonencapsulated device retains 83.4% of its initial efficiency after aging at 25% relative humidity for 1540 h. More importantly, the target device shows good operational stability and reveals the unfallen efficiency after maximum power point tracking for 350 h at 45 °C. Our work offers a feasible method to fabricate efficient and stable CsPbI₂Br IPSCs for future commercialization.

中文翻译：

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高效，稳定的CsPbI ₂ Br无机钙钛矿太阳能电池的双重保护策略

开路电压（V _oc）的大损失和湿气稳定性差已严重阻碍了无机钙钛矿太阳能电池（IPSC）的发展。在这里，我们报告了通过将单体三羟甲基丙烷三丙烯酸酯（TMTA）掺入CsPbI ₂ Br钙钛矿块中并用2-噻吩甲基碘化铵（Th-NI）覆盖表面来改善上述问题的双重保护策略。得益于生长控制和有效抑制体相和表面复合的作用，最终的器件在V _oc冠军的情况下效率从12.17％大幅提高到15.58％。此外，双重保护策略使薄膜具有增强的耐湿性，并且未封装的器件在25％相对湿度下老化1540 h后，仍保持其初始效率的83.4％。更重要的是，目标器件在45°C下最大功率点跟踪350 h后显示出良好的操作稳定性并显示出不降低的效率。我们的工作提供了一种可行的方法来制造高效稳定的CsPbI ₂ Br IPSC，以备将来商业化。