Xia Xuefeng, Peng Jiayi, Wan Qixin, Wang Xiaofeng, Fan Zhiping, Zhao Jie, Li Fan
Department of Materials Science and Engineering, Nanchang University, 999 Xuefu Avenue, Nanchang 330031, China.
Key Laboratory for Optoelectronics and Communication of Jiangxi Province, Jiangxi Science and Technology Normal University, Nanchang 330013, China.
ACS Appl Mater Interfaces. 2021 Apr 21;13(15):17677-17689. doi: 10.1021/acsami.1c02728. Epub 2021 Apr 12.
Organic-inorganic hybrid perovskite solar cells (PSCs) have emerged as a promising candidate for next-generation solar cells. However, the limited stability of PSCs hampers their practical applications. In this work, for the first time, a functionalized π-conjugated ionic liquid crystal (ILC), 4'-(,,-trimethyl ammonium bromide hexyloxy)-4-cyanobiphenyl (6CNBP-N), is developed as a novel chemical additive to obtain CHNHPbI (MAPbI) PSCs with high efficiency and excellent moisture stability. This 6CNBP-N ILC possesses the characteristics of ionic liquids and liquid crystals. The inclusion of the 6CNBP-N ILC can effectively improve the quality and stability of perovskite films, reduce the trap-state densities, and promote the carrier transport induced by the cyano group (C≡N), a rod-like π-conjugated biphenyl mesogenic unit and quaternary alkylammonium cations (RN) in 6CNBP-N. Through this functionalized ILC engineering strategy, the power conversion efficiency (PCE) of PSCs is greatly increased from 18.07% for the control PSC to 20.45% for the PSC with 6CNBP-N along with the depressed hysteresis effect and enhanced moisture stability of PSCs. Our work provides a new strategy for designing functionalized additives for high-performance PSCs.
有机-无机杂化钙钛矿太阳能电池（PSCs）已成为下一代太阳能电池的一个有前途的候选者。然而，PSCs有限的稳定性阻碍了它们的实际应用。在这项工作中，首次开发了一种功能化的π共轭离子液晶（ILC），4'-(,, -三甲基溴化铵己氧基)-4-氰基联苯（6CNBP-N），作为一种新型化学添加剂，以获得具有高效率和优异耐湿性的CHNHPbI（MAPbI）PSCs。这种6CNBP-N ILC具有离子液体和液晶的特性。包含6CNBP-N ILC可以有效地提高钙钛矿薄膜的质量和稳定性，降低陷阱态密度，并促进由6CNBP-N中的氰基（C≡N）、棒状π共轭联苯介晶单元和季铵阳离子（RN）诱导的载流子传输。通过这种功能化的ILC工程策略，PSCs的功率转换效率（PCE）从对照PSCs的18.07%大幅提高到含有6CNBP-N的PSCs的20.45%，同时PSCs的滞后效应得到抑制，耐湿性增强。我们的工作为设计用于高性能PSCs的功能化添加剂提供了一种新策略。
