Nickel oxide (NiO_x) as a hole-transporting layer (HTL) in perovskite solar cells (PSCs) has been studied extensively in recent years. However, unlike the solution-processed NiO_x films, magnetron sputtered NiO_x exhibits relatively low conductivity and imperfect band alignment with perovskites, severely limiting the device performance of PSCs. In this study, a synergistically combined strategy consisting of triple interface treatments – including post-annealing, O₂-plasma, and potassium chloride treatments – is employed to modulate the optoelectronic properties of the sputtered NiO_x films. Through this approach, we successfully obtained NiO_x films with increased carrier density and conductivity, better energy level alignment with the perovskite absorber layer, reduced interface trap density, and improved interfacial charge extraction. PSCs using this modified sputtered NiO_x as the HTL deliver a highest stabilized efficiency of 18.7%. Our result offers an alternative method to manipulate sputtered NiO_x thin film properties and thereby sheds light on a manufacturing pathway to perovskite solar cells featuring sputtered NiO_x HTL.

中文翻译：

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溅射NiOx的界面修饰作为空穴传输层，用于高效倒置平面钙钛矿太阳能电池

近年来，钙钛矿型太阳能电池（PSC）中作为空穴传输层（HTL）的氧化镍（NiO _x）得到了广泛的研究。然而，与溶液处理的NiO _x膜不同，磁控溅射NiO _x表现出相对较低的电导率和与钙钛矿的不完全能带对准，严重限制了PSC的器件性能。在这项研究中，采用了由三重界面处理（包括后退火，O ₂等离子体和氯化钾处理）组成的协同组合策略，以调节溅射NiO _x膜的光电性能。通过这种方法，我们成功获得了NiO _x具有增加的载流子密度和电导率，与钙钛矿吸收层更好的能级对准，降低的界面陷阱密度和改善的界面电荷提取的薄膜。使用这种改良的溅射NiO _x作为HTL的PSC可以实现18.7％的最高稳定效率。我们的结果提供了一种控制溅射NiO _x薄膜特性的替代方法，从而为制造具有溅射NiO _x HTL的钙钛矿型太阳能电池提供了一条途径。