The formation of smooth, dense, and uniform perovskite layers on substrates is crucial for achieving high-performance perovskite devices. Here, we show that the introduction of a small concentration of cesium iodide to the precursor solution has a considerable effect on the morphology, phase and optoelectronic properties of CH₃NH₃PbI₃-based perovskite films. An optimized concentration of 3% produces a high-quality perovskite film with a large grain size of ∼1.8 μm and a root mean square roughness of 5.917 nm. The improved morphology and high optoelectronic quality of the perovskite layer were verified by SEM, AFM, XRD, and UV-visible, photoluminescence and electrochemical impedance spectroscopy. The defect-free thin perovskite layer enables the fabrication of a mesoscopic CH₃NH₃PbI₃-based perovskite device under ambient conditions, with a maximum power conversion efficiency of ∼19% with negligible hysteresis and high reproducibility. This method can be extended to other complexes of perovskite used in the present state-of-the-art perovskite solar cells.

中文翻译：

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用碘化铯调节钙钛矿薄膜的晶粒尺寸，相位和光电质量高性能太阳能电池†

在基材上形成光滑，致密和均匀的钙钛矿层对于实现高性能钙钛矿设备至关重要。在这里，我们表明向前体溶液中引入低浓度的碘化铯对CH ₃ NH ₃ PbI ₃的形貌，相和光电性质具有相当大的影响。钙钛矿膜。优化的3％浓度可生产出高质量的钙钛矿薄膜，其晶粒尺寸约为1.8μm，均方根粗糙度为5.917 nm。通过SEM，AFM，XRD，紫外可见光，光致发光和电化学阻抗谱验证了钙钛矿层的改善的形态和高光电质量。无缺陷的钙钛矿薄层使得能够在环境条件下制造介观的基于CH ₃ NH ₃ PbI ₃的钙钛矿器件，最大功率转换效率约为19％，滞后可以忽略不计，并且具有高再现性。该方法可以扩展到在当前技术水平的钙钛矿太阳能电池中使用的钙钛矿的其他配合物。