Efficient and stable Ruddlesden–Popper perovskite solar cell with tailored interlayer molecular interaction

• Published in: Nature photonics Vol. 14; no. 3; pp. 154 - 163
• Main Authors: Ren, Hui, Yu, Shidong, Chao, Lingfeng, Xia, Yingdong, Sun, Yuanhui, Zuo, Shouwei, Li, Fan, Niu, Tingting, Yang, Yingguo, Ju, Huanxin, Li, Bixin, Du, Haiyan, Gao, Xingyu, Zhang, Jing, Wang, Jianpu, Zhang, Lijun, Chen, Yonghua, Huang, Wei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.03.2020; Nature Publishing Group
• Subjects: 639/301; 639/301/299; 639/301/299/946; Applied and Technical Physics; Charge transport; Dimensional stability; Efficiency; Energy conversion efficiency; High temperature; Interlayers; Maximum power; Moisture; Molecular interactions; Perovskites; Photovoltaic cells; Physics; Physics and Astronomy; Quantum Physics; Solar cells; Sulfur; Thermal stability
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/s41566-019-0572-6

Two-dimensional Ruddlesden–Popper phase (2DRP) perovskites are known to exhibit improved photostability and environmental stability compared with their three-dimensional (3D) counterparts. However, fundamental questions remain over the interaction between the bulky alkylammoniums and the 2DRP perovskite framework. Here, we unambiguously demonstrate that a sulfur–sulfur interaction is present for a new bulky alkylammonium, 2-(methylthio)ethylamine hydrochloride (MTEACl). In addition to a weaker van der Waals interaction, the interaction between sulfur atoms in two MTEA molecules enables a (MTEA) 2 (MA) 4 Pb 5 I 16 ( n  = 5) perovskite framework with enhanced charge transport and stabilization. The result is 2DRP perovskite solar cells with significantly improved efficiency and stability. Cells with a power conversion efficiency as high as 18.06% (17.8% certified) are achieved, along with moisture tolerance for up to 1,512 h (under 70% humidity conditions), thermal stability for 375 h (at 85 °C) and stability under continuous light stress (85% of the initial efficiency retained over 1,000 h of operation at the maximum power point). Two-dimensional perovskite solar cells have been engineered to be robust against moisture, high temperatures and light stress.