Investigating the low efficiency issue of radio frequency‐sputtered nickel oxide (sp‐NiO_x)‐based perovskite solar cells (PSCs) due to a limited understanding of the correlation between perovskite growth and sp‐NiO_x on the optoelectronic properties and photovoltaic device performance is critical. Herein, the crystallization of methylammonium (MA) lead iodide (MAPbI₃) thin film (obtained from stoichiometric precursor ratio) on sp‐NiO_x is shown, resulting in appearance of residual PbI₂ grains. This is in contrast to perovskite growth on solution‐processed NiO_x. The amount of residual PbI₂ is suppressed by 1) adding excess MACl/MAI additives and 2) annealing the perovskite film in MACl/MAI vapor atmosphere. Structural and morphological results reveal significant reduction in the amount of residual PbI₂ and enhanced grain size for all the cases while photophysical measurements reveal mitigation of trap/defect sites (within the bulk and at the interfaces) only for MACl/MAI vapor annealing case. As a result, photovoltaic devices exhibit improved performance only for the vapor annealing case. These results elucidate the critical role of maintaining stoichiometric ratio in perovskite and its crystallization on sp‐NiO_x by eliminating the associated defects (influenced by sp‐NiO_x) in rendering improved performance, which can be insightful to further enhance the performance of PSCs.

中文翻译：

---

研究用于反向平面钙钛矿太阳能电池的RF溅射NiOx上CH3NH3PbI3薄膜的生长：CH3NH3 +卤化物添加剂与CH3NH3 +卤化物蒸汽退火的影响

由于对钙钛矿生长与sp-NiO _x之间在光电性能和光伏器件性能之间的相关性的了解有限，因此研究了基于射频溅射氧化镍（sp-NiO _x）的钙钛矿太阳能电池（PSC）的低效率问题至关重要。此处显示了在sp‐NiO _x上甲基铵（MA）碘化铅（MAPbI ₃）薄膜的结晶（从化学计量的前体比获得），导致出现了残留的PbI ₂晶粒。这与固溶处理后的NiO _x上钙钛矿的生长形成对比。残留PbI ₂的量通过1）添加过量的MAC1 / MAI添加剂和2）在MAC1 / MAI蒸气气氛中对钙钛矿膜进行退火来抑制这种情况。结构和形态学结果表明，在所有情况下，残留PbI ₂的数量均显着减少，晶粒尺寸增大，而光物理测量结果表明，仅在MAC1 / MAI气相退火的情况下，捕集/缺陷位点（在主体内和界面处）得到了缓解。结果，光生伏打器件仅在蒸气退火的情况下表现出改进的性能。这些结果阐明了通过消除相关的缺陷（受sp-NiO _x影响）在钙钛矿中保持化学计量比及其在sp-NiO _x上结晶的关键作用。）以提高性能，这对于进一步提高PSC的性能很有帮助。