Toward high-efficiency, hysteresis-less, stable perovskite solar cells: unusual doping of a hole-transporting material using a fluorine-containing hydrophobic Lewis acid. Issue 8 (13th April 2018)

• Record Type: Journal Article
• Authors: Luo, Junsheng; Xia, Jianxing; Yang, Hua; Chen, Lingling; Wan, Zhongquan; Han, Fei; Malik, Haseeb Ashraf; Zhu, Xuhui; Jia, Chunyang
• Is Part Of: Energy & environmental science. Volume 11:Issue 8(2018)
• Page Start: 2035
• Page End: 2045
• Publication Date: 2018-04-13
• Subjects: Energy conversion -- Periodicals; Fuel switching -- Periodicals; Environmental sciences -- Periodicals; Environmental chemistry -- Periodicals; 333.79
• DOI: 10.1039/c8ee00036k
• Languages: English
• ISSNs: 1754-5692

Abstract

Abstract : A fluorine-containing hydrophobic Lewis acid is employed as an effective dopant for PTAA to replace state-of-the-art Li-TFSI/ t -BP in PSCs. Abstract : Perovskite solar cells (PSCs) have demonstrated high power conversion efficiency (PCE) but inferior long-term stability and remarkable hysteresis. To date, the most efficient PSCs have a n–i–p device architecture and use Li-TFSI/ t -BP as standard bi-dopants for the hole-transporting layer (HTL). However, such dopants not only induce deleterious effects on stability but also significantly affect the hysteresis of PSCs. Here, we demonstrate that a fluorine-containing hydrophobic Lewis acid dopant (LAD) can be employed as an effective dopant for PTAA to realize an exceptional fill factor of 0.81 and a record PCE as high as 19.01%, the highest value among the ever reported PSCs based on a novel dopant in the HTL, versus 17.77% for the control device with Li-TFSI/ t -BP doped PTAA. To the best of our knowledge, this is the first case in which a PSC based on a novel dopant for the HTL shows higher efficiency than a PSC based on the state-of-the-art bi-dopants Li-TFSI/ t -BP. Besides, the LAD-based PSC displays lower J – V hysteresis and much better long-term stability of up to 70 days under air exposure without encapsulation. We believe that this work will pave a new avenue for high-efficiency, hysteresis-less and stable PSCs exploring hydrophobic dopants as alternatives to hydrophilic Li-TFSI/ t -BP.