Solvent-engineering-processed CsPbIBr2 inorganic perovskite solar cells with efficiency of ∼11%
Solvent-engineering-processed CsPbIBr2 inorganic perovskite solar cells with efficiency of ∼11%
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DOI：
10.1016/j.solmat.2022.111640
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发表时间：
2022-05
影响因子：
6.9
通讯作者：
Haisheng Wang;Jia Sun;Yinsheng Gu;Chenqiang Xu;Ying‐Wei Lu;Juntao Hu;Tao Chen;Changfei Zhu
中科院分区：
文献类型：
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作者：
Haisheng Wang;Jia Sun;Yinsheng Gu;Chenqiang Xu;Ying‐Wei Lu;Juntao Hu;Tao Chen;Changfei Zhu
近年来，铯卤化铅钙钛矿(CsPbIBr2)材料在所有的无机钙钛矿类似物中具有最平衡的带隙和稳定性，受到了光伏领域的极大关注。然而，溶液法制备的CsPbIBr2薄膜具有细小的颗粒和大量的空洞和缺陷，严重阻碍了其进一步发展。这一障碍主要源于使用传统的高沸点溶剂二甲基亚砜(DMSO)时，钙钛矿的结晶过程缓慢。本文首次提出了一种新的溶剂工程策略，即乙醇诱导快速结晶法。我们有意加入一些低沸点的醇，如甲醇、乙醇、异丙醇和正丁醇，形成低沸点的DMSO-醇共沸混合物，该混合物可以快速挥发，有效地加速了CsPbIBr2薄膜的结晶过程。同时，我们精心地采用了一些CSI添加剂来抑制钙钛矿的本征自掺杂，钝化钙钛矿的缺陷。此外，本文还研究了退火温度对薄膜质量和器件性能的影响。因此，CsPbIBr2薄膜通过CsI/甲醇处理配方在280℃的最佳温度下进行热处理，成功地获得了无针孔、高度结晶的大颗粒、(100)择优取向的CsPbIBr2薄膜。所获得的钙钛矿型太阳能电池(PSCs)具有良好的长期稳定性，其功率转换效率(PCE)达到了11.49%。据我们所知，这是所有CsPbIBr2无机PSC中报道的最高效率。
Recently, the cesium lead halide perovskite (CsPbIBr2) materials demonstrating the most balanced bandgap and stability among all inorganic perovskite analogs have received great attention in photovoltaic community. However, the poor quality of solution-processed CsPbIBr2films with small grains and massive voids and defects severely impedes its further development. This obstacle issue mainly roots from the slow crystallization process of perovskites when using traditional high boiling point solvent of dimethyl sulfoxide (DMSO). Herein, a novel solvent engineering strategy, namely alcohol-induced rapid crystallization process, is originally developed. We intentionally add some low boiling point alcohols, such as methanol, ethanol, isopropanol, and n-butanol, to form a lower boiling point DMSO-alcohol azeotropic mixture, which can be volatilized quickly and effectively accelerate the crystallization process of CsPbIBr2films. Meanwhile, we elaborately adopt some CsI additives to suppress the intrinsic self-doping and passivate the defects of perovskites. Besides, the influence of annealing temperatures on the film quality and device performance is also investigated in this study. Consequently, the pinhole-free, highly crystallized CsPbIBr2films with large grains and a preferable (100) orientation are successfully achieved via CsI/methanol treatment recipe when annealed at the optimized temperature of 280 °C. The as-obtained perovskite solar cells (PSCs) with a superior long-term stability feature yield a highly promising power conversion efficiency (PCE) of 11.49%. To our knowledge, this is the highest reported efficiency among all CsPbIBr2inorganic PSCs.