Here we demonstrate an innovative compositional and interfacial engineering approach to achieve Pb-free flexible perovskite solar cells (f-PSCs) with an unprecedented combination of the highest efficiency reported to date (10.43%), together with enhanced operational stability and mechanical reliability. The key to this approach is alloying of an FASnI₃ metal halide perovskite (MHP) thin film with Ge²⁺ to stabilize the Sn²⁺ oxidation state in the MHP, together with the use of a NiO_x hole-transport layer. We show that this results in the in situ formation of a thin amorphous GeO₂ native oxide layer at the NiO_x/FASn_0.9Ge_0.1I₃ interface. This layer not only passivates that critical interface but also enhances the interfacial mechanical bonding.

中文翻译：

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具有界面原生氧化物的无铅柔性钙钛矿太阳能电池具有 >10% 的效率并同时增强了稳定性和可靠性

在这里，我们展示了一种创新的成分和界面工程方法来实现无铅柔性钙钛矿太阳能电池 (f-PSCs)，它前所未有地结合了迄今为止报道的最高效率 (10.43%)，以及增强的操作稳定性和机械可靠性。这种方法的关键是将FASnI ₃金属卤化物钙钛矿（MHP）薄膜与Ge ²⁺合金化以稳定MHP中的Sn ²⁺氧化态，同时使用NiO _x空穴传输层。我们表明，这导致在NiO _x /FASn _0.9 Ge处原位形成薄的非晶 GeO ₂天然氧化物层_0.1 I ₃接口。该层不仅钝化了关键界面，而且增强了界面机械结合。