External encapsulation technique as a straightforward craft process has been adopted to prevent the infiltration of moisture and oxygen, thereby improving environmental stabilities of lead halide perovskite solar cells (PSCs). However, irreversible light-induced degradation originating from various vacancies and ion diffusion or migration inside the device cannot be efficiently solved by external encapsulation. Herein, an internal encapsulation strategy by introducing NbCl₅ at the buried tin oxide/perovskite interface and spin-casting n-butylammonium bromide on top of perovskite is developed to comprehensively passivate the vacancies and hence block the channels for ion diffusion or migration. The internal encapsulation strategy results in better homogeneous electron transport layer and effective vacancy passivation at the buried interface and simultaneously generates a more homogeneous, better crystallized perovskite in the vertical direction with significantly reduced residual PbI₂. Furthermore, fewer oxygen vacancies and formation of ultrathin Nb₂O₅ lead to a better interfacial energy level alignment for electron transfer. As a result, power conversion efficiency (PCE) of the resulting PSCs is as high as 24.01%. More importantly, the device demonstrates an excellent stability, retaining 88% of its initial PCE at its maximum power point tracking measurement (under 100 mW cm^–2 white light illumination at ≈55 °C temperature, in N₂ atmosphere) after 1000 h.

中文翻译：

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用于高效且非常稳定的太阳能电池的卤化铅钙钛矿薄膜的内部封装

采用外部封装技术作为一种简单的工艺工艺，可防止水分和氧气的渗透，从而提高卤化铅钙钛矿太阳能电池（PSC）的环境稳定性。然而，外部封装无法有效解决器件内部各种空位和离子扩散或迁移引起的不可逆光致降解。在此，通过在掩埋氧化锡/钙钛矿界面引入 NbCl ₅并旋转铸造n的内部封装策略开发钙钛矿顶部的-丁基溴化铵以全面钝化空位，从而阻断离子扩散或迁移的通道。内部封装策略在掩埋界面处产生更均匀的电子传输层和有效的空位钝化，同时在垂直方向上产生更均匀、更好结晶的钙钛矿，并显着减少残留的 PbI ₂。此外，更少的氧空位和超薄Nb ₂ O _5的形成为电子转移带来更好的界面能级排列。因此，所得 PSC 的功率转换效率 (PCE) 高达 24.01%。更重要的是，该器件表现出出色的稳定性，在其最大功率点跟踪测量（在 100 mW cm ^–2白光照射下，≈55 °C 温度下，N ₂气氛中）1000 小时后保持其初始 PCE 的 88%。