Zhuang Xinmeng, Chen Xinfu, Xu Lin, Liu Shuainan, Wu Yanjie, Shi Zhichong, Zhou Qingqing, Li Bo, Yan Haixia, Reiss Peter, Song Hongwei
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, People's Republic of China.
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, People's Republic of China.
J Colloid Interface Sci. 2022 Sep 15;622:469-480. doi: 10.1016/j.jcis.2022.04.117. Epub 2022 Apr 27.
Long-term stability remains a great challenge for metal halide perovskite solar cells (PSCs). The utilization of ionic liquids (ILs) is a promising strategy to solve the stability problem. However, few studies have focused on controlling the halide anions of ILs, in which different organic cations can modulate the melting point of ILs and film crystal growth. Here, ILs with a 1-ethyl-3-methylimidazolium (EMIM) cation and different halide anions (X = Cl, Br, and I) are employed in inverted PSCs. The results show that EMIMX can form a 1D passivation layer by the in situ growth technique and influence the surface morphology of the perovskite film. These EMIMX-treated layers simultaneously suppress the surface defects and nonradiative energy losses and improve the hydrophobic properties. As a result, a power conversion efficiency (PCE) of 20.0% is obtained for the EMIMBr-modified PSCs compared to 18.06% for the control device. Moreover, the unencapsulated devices maintain more than 90% of their initial PCE over 3000 h under ambient air, which is among the best long-term stabilities reported for NiO-based inverted PSCs. It also retains 74.2% and 49.5% of the initial PCE value after aging under harsher conditions, such as an 85 ± 5% relative humidity (RH) environment and at 85 °C for 48 h, respectively.
长期稳定性仍然是金属卤化物钙钛矿太阳能电池（PSC）面临的巨大挑战。离子液体（IL）的使用是解决稳定性问题的一种很有前景的策略。然而，很少有研究关注控制IL的卤化物阴离子，其中不同的有机阳离子可以调节IL的熔点和薄膜晶体生长。在此，具有1-乙基-3-甲基咪唑鎓（EMIM）阳离子和不同卤化物阴离子（X = Cl、Br和I）的IL被应用于倒置PSC中。结果表明，EMIMX可以通过原位生长技术形成一维钝化层，并影响钙钛矿薄膜的表面形貌。这些经EMIMX处理的层同时抑制了表面缺陷和非辐射能量损失，并改善了疏水性能。结果，EMIMBr修饰的PSC的功率转换效率（PCE）达到20.0%，而对照器件为18.06%。此外，未封装的器件在环境空气中3000小时内保持其初始PCE的90%以上，这是基于NiO的倒置PSC报道的最佳长期稳定性之一。在更苛刻的条件下老化后，它还分别保留了初始PCE值的74.2%和49.5%，例如在85±5%相对湿度（RH）环境和85°C下48小时。
