Inorganic perovskites with cesium (Cs⁺) as the cation have great potential as photovoltaic materials if their phase purity and stability can be addressed. Herein, a series of inorganic perovskites is studied, and it is found that the power conversion efficiency of solar cells with compositions CsPbI_1.8Br_1.2, CsPbI_2.0Br_1.0, and CsPbI_2.2Br_0.8 exhibits a high dependence on the initial annealing step that is found to significantly affect the crystallization and texture behavior of the final perovskite film. At its optimized annealing temperature, CsPbI_1.8Br_1.2 exhibits a pure orthorhombic phase and only one crystal orientation of the (110) plane. Consequently, this allows for the best efficiency of up to 14.6% and the longest operational lifetime, T_S80, of ≈300 h, averaged of over six solar cells, during the maximum power point tracking measurement under continuous light illumination and nitrogen atmosphere. This work provides essential progress on the enhancement of photovoltaic performance and stability of CsPbI_3 − xBr_x perovskite solar cells.

中文翻译：

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管理高性能和光稳定的铯铅卤化钙钛矿型太阳能电池的相纯度和晶体取向

如果可以解决它们的相纯度和稳定性问题，则以铯（Cs ⁺）为阳离子的无机钙钛矿有很大的发展潜力。本文中，研究了一系列无机钙钛矿，发现组成为CsPbI _1.8 Br _1.2，CsPbI _2.0 Br _1.0和CsPbI _2.2 Br _0.8的太阳能电池的功率转换效率表现出对初始退火步骤的高度依赖性，即发现显着影响最终钙钛矿薄膜的结晶和织构行为。在最佳退火温度下，CsPbI _1.8 Br _1.2呈现纯正交相，并且（110）平面只有一个晶体取向。因此，在连续光照和氮气环境下进行最大功率点跟踪测量期间，这可以实现最高效率14.6％的最高效率，≈300 h的最长工作寿命T _S80（平均超过六个太阳能电池）。这项工作为增强CsPbI _{3-  x} Br _x钙钛矿型太阳能电池的光伏性能和稳定性提供了重要的进展。