Synergistic passivation by alkali metal and halogenoid ions for high efficiency HTM-free carbon-based CsPbI2Br solar cells
Synergistic passivation by alkali metal and halogenoid ions for high efficiency HTM-free carbon-based CsPbI2Br solar cells
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碱金属和卤离子协同钝化用于高效无 HTM 碳基 CsPbI2Br 太阳能电池
DOI：
10.1016/j.cej.2021.133083
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发表时间：
2022
影响因子：
15.1
通讯作者：
Zhong Xinhua
中科院分区：
文献类型：
--
作者：
Yang Zechao;Zhang Guizhi;Zhang Jianxin;Pan Zhenxiao;Yang Siyuan;Liu Boping;Rao Huashang;Zhong Xinhua
空穴传输材料(HTM)无碳基全无机钙钛矿太阳能电池(C-PSCs)具有良好的热稳定性和低成本，有望替代传统的有机-无机混合PSCs。添加剂法是通过改善钙钛矿薄膜的质量来提高PSCs性能的有效途径。本文采用碱金属和卤代离子在NaSCN添加剂中的协同钝化策略来抑制CsPbI2Br膜的非辐射复合。Na+被掺入CsPbI2Br电池的A位，使I-−扩散势垒能从0.229 eV提高到0.401 eV，表明碘空位被抑制。此外，SCN−在CsPbI2Br膜的形成过程中起到了调节晶体生长动力学的作用，降低了缺陷密度。这种协同钝化策略有效地改善了钙钛矿薄膜的质量，增加了CsPbI2Br膜的复合电阻和载流子提取效率，从而降低了最终器件中的非辐射复合损耗。组装的高温超导无碳基全无机CsPbI2Br型钙钛矿电池的峰值电流效率为14.63%(VOC=1.267 mA/cm~2，Jsc=14.31 mA/cm~2，填充因子(Ff)=0.807)，是碳基全无机钙钛矿太阳能电池中性能最好的电池之一。
Hole transport material (HTM)-free carbon-based all-inorganic perovskite solar cells (C-PSCs) possess excellent thermal stability and low cost, which promise an alternative to replace the conventional organic–inorganic hybrid PSCs. The additive method is an effective approach to enhance the performance of PSCs by improving the quality of perovskite films. Herein, the synergistic passivation strategy of alkali metal and halogenoid ions in NaSCN additive is adopted to suppress nonradiative recombination in CsPbI2Br films. The Na+is incorporated at the A-site of CsPbI2Br cell that enhances the I−diffusion barrier energy from 0.229 eV to 0.401 eV, suggesting suppressed iodide vacancy. Moreover, the SCN−plays a role in regulating the crystal growth dynamics during the CsPbI2Br film formation process, reducing defect density. This synergistic passivation strategy effectively improves the perovskite film quality, and increases the recombination resistance and the carrier extraction efficiency of CsPbI2Br films, therefore reducing nonradiative recombination loss in the final device. The assembled HTM-free carbon-based all-inorganic CsPbI2Br perovskite solar cells present a champion PCE of 14.63% (VOC= 1.267 V,JSC= 14.31 mA/cm2, fill factor (FF) = 0.807), which is among the best performances in the carbon-based all-inorganic perovskite solar cells.