Controlling the crystallization dynamics is one key in optimizing the performance of perovskite solar cells (PSCs). The present study provides a simple approach using a low temperature stable-transition-film (STF) to prepare highly-dense and pinhole-free CsPbIBr₂ thin film with high crystalline quality, as well as a new structural design (FTO/NiO_x/CsPbIBr₂/MoO_x/Au) of all-inorganic perovskite solar cells toward long-term thermal stability. For the first time, we demonstrate that MoO_x can independently serve as an outstanding cathode buffer layer on an inorganic perovskite layer. The lower work-function MoO_x with ultra-thin thickness (4 nm) leads to decreases of the Schottky barrier, the contact resistance and the interface trap-state density. This increases the power conversion efficiency (PCE) of all-inorganic planar PSCs from 1.3% to 5.52%. Inspiringly, the FTO/NiO_x/CsPbIBr₂/MoO_x/Au all-inorganic PSCs were demonstrated to possess excellent long-term thermal stability at high temperatures up to 160 °C.

中文翻译：

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超薄MoO _x作为阴极缓冲层，用于改善全无机CsPbIBr ₂钙钛矿太阳能电池

控制结晶动力学是优化钙钛矿太阳能电池（PSC）性能的关键之一。本研究提供了一种使用低温稳定过渡膜（STF）来制备具有高结晶质量的高密度且无针孔的CsPbIBr ₂薄膜的简单方法，以及一种新的结构设计（FTO / NiO _x /全无机钙钛矿型太阳能电池的CsPbIBr ₂ / MoO _x / Au）具有长期的热稳定性。首次，我们证明了MoO _x可以独立地用作无机钙钛矿层上的出色阴极缓冲层。下功函数MoO _x具有超薄厚度（4 nm）的薄膜导致肖特基势垒，接触电阻和界面陷阱态密度减小。这将所有无机平面PSC的功率转换效率（PCE）从1.3％提高到5.52％。令人鼓舞的是，FTO / NiO _x / CsPbIBr ₂ / MoO _x / Au全无机PSC被证明在高达160°C的高温下具有出色的长期热稳定性。