Side-Chain Engineering on Dopant-Free Hole-Transporting Polymers toward Highly Efficient Perovskite Solar Cells (20.19%)

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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  • Luozheng Zhang
  • Chang Liu
  • Xingzhu Wang
  • Yanqing Tian
  • Baomin Xu


Original languageEnglish
Article number1904856
Journal / PublicationAdvanced Functional Materials
Issue number39
Online published1 Aug 2019
Publication statusPublished - 26 Sep 2019


A variety of dopant-free hole-transporting materials (HTMs) is developed to serve as alternatives to the typical dopant-treated ones; however, their photovoltaic performance still falls far behind. In this work, the side chain of a polymeric HTM is engineered by partially introducing diethylene glycol (DEG) groups in order to simultaneously optimize the properties of both the bulk of the HTM layer and the HTM/perovskite interface. The intermolecular π–π stacking interaction in the HTM layer is unexpectedly weakened after the incorporation of DEG groups, whereas the lamellar packing interaction is strengthened. A doubled hole mobility is obtained when 3% of the DEG groups replace the original alkyl side chains, and a champion power conversion efficiency (PCE) of 20.19% (certified: 20.10%) is then achieved, which is the first report of values over 20% for dopant-free organic HTMs. The device maintains 92.25% of its initial PCE after storing at ambient atmosphere for 30 d, which should be due to the enhanced hydrophobicity of the HTM film.

Research Area(s)

  • dopant-free, hole-transporting, perovskite solar cells, polymers, side chains

Citation Format(s)