MAAc Ionic Liquid-Assisted Defect Passivation for Efficient and Stable CsPbIBr2 Perovskite Solar Cells
MAAc Ionic Liquid-Assisted Defect Passivation for Efficient and Stable CsPbIBr2 Perovskite Solar Cells
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MAAc 离子液体辅助缺陷钝化，用于高效稳定的 CsPbIBr2 钙钛矿太阳能电池
DOI：
10.1021/acsaem.1c01537
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发表时间：
2021
影响因子：
6.4
通讯作者：
Dongen Zhang
中科院分区：
文献类型：
--
作者：
Linxing Shi;Haoyang Yuan;Xianggang Sun;Xinyi Li;Wenbo Zhu;Jie Wang;Liangsheng Duan;Qile Li;Zhen Zhou;Zengguang Huang;Xinxin Ban;Dongen Zhang
铯基全无机钙钛矿太阳能电池（PSCs），如CsPbIBr2 PSCs，因其良好的热稳定性和湿稳定性而受到广泛关注，但CsPbIBr2薄膜覆盖不足导致的低开路电压（Voc）是限制其发展的主要原因。在TiO2衬底上直接生长的CsPbIBr2薄膜具有大量的针孔，这带来了大量的缺陷，导致非辐射复合的增加。在这项工作中，通过在沉积CsPbIBr2薄膜之前将醋酸甲基铵（MAAc）离子液体预涂在TiO2层上，扩展了CsPbIBr2薄膜的策略。均匀分布的MA+将成为CsPbIBr2薄膜底部的成核中心，这对CsPbIBr2薄膜的结晶动力学有显著影响。该效应同时增强了CsPbIBr2薄膜的晶体质量和电子传递层（ETL）与CsPbIBr2层之间的界面接触。它有助于降低陷阱态密度，抑制非辐射复合，提取载流子。因此，优化后的器件稳定性得到了显著提高，冠军功率转换效率（PCE）高达8.85%，Voc高达1.26 V。受益于钝化，经过2 M MAAc IL界面修饰的PSC在室温下暴露于环境空气30天后仍保持其初始PCE的82%。
Cesium-based all-inorganic perovskite solar cells (PSCs), such as CsPbIBr2 PSCs, have attracted wide attention for good thermal and wet stability, but the low open-circuit voltage (Voc) mainly caused by the inadequate coverage of CsPbIBr2 films is the main reason for limiting their development. The CsPbIBr2 films grown on TiO2 substrate directly have a large number of pinholes, which bring a lot of defects and lead to an increase of nonradiative recombination. In this work, a strategy extended for CsPbIBr2 films by precoating methylammonium acetate (MAAc) ionic liquid onto a TiO2 layer before depositing the CsPbIBr2 film is demonstrated. The uniformly distributed MA+ will be the nucleation center at the bottom of the CsPbIBr2 film, which exhibited a notable impact on the crystallization kinetics of CsPbIBr2 films. This effect simultaneously enhanced the crystal quality of the CsPbIBr2 film and interfacial contact between the electron transporting layer (ETL) and CsPbIBr2 layer. It is instrumental in decreasing the trap state density, suppressing nonradiative recombination, and extracting the charge carriers. Therefore, the stability of the optimized device has been improved considerably, and the champion power conversion efficiency (PCE) is up to 8.85% with a high Voc of 1.26 V. Benefiting from passivation, the PSC with 2 M MAAc IL interfacial modification remains 82% of its initial PCE after 30 days of exposing the device to ambient air at room temperature.