Multifunctional Conjugated Ligand Engineering for Stable and Efficient Perovskite Solar Cells

Ke Ma, Harindi R. Atapattu, Qiuchen Zhao, Yao Gao, Blake P. Finkenauer, Kang Wang, Ke Chen, So Min Park, Aidan H. Coffey, Chenhui Zhu, Libai Huang, Kenneth R. Graham, Jianguo Mei, Letian Dou

Research output: Contribution to journalArticlepeer-review

86 Scopus citations


Surface passivation is an effective way to boost the efficiency and stability of perovskite solar cells (PSCs). However, a key challenge faced by most of the passivation strategies is reducing the interface charge recombination without imposing energy barriers to charge extraction. Here, a novel multifunctional semiconducting organic ammonium cationic interface modifier inserted between the light-harvesting perovskite film and the hole-transporting layer is reported. It is shown that the conjugated cations can directly extract holes from perovskite efficiently, and simultaneously reduce interface non-radiative recombination. Together with improved energy level alignment and the stabilized interface in the device, a triple-cation mixed-halide medium-bandgap PSC with an excellent power conversion efficiency of 22.06% (improved from 19.94%) and suppressed ion migration and halide phase segregation, which lead to a long-term operational stability, is demonstrated. This strategy provides a new practical method of interface engineering in PSCs toward improved efficiency and stability.

Original languageEnglish
Article number2100791
JournalAdvanced Materials
Issue number32
StatePublished - Aug 12 2021

Bibliographical note

Funding Information:
This work was supported by the US Office of Naval Research (award no. N00014‐19‐1‐2296 to L.D.; program managers: J. Parker and P. Armistead), the Davidson School of Chemical Engineering, and College of Engineering of Purdue University. K.M. acknowledges the support from the Lillian Gilbreth Postdoctoral Fellowship from College of Engineering of Purdue University. L.H. acknowledges the support from US Department of Energy, Office of Basic Energy Sciences through award no. DE‐SC0016356. H.R.A., S.M.P., and K.R.G. acknowledge the U.S. Department of Energy under Grant DE‐SC0018208 for supporting the UPS, IPES, and XPS measurements. The authors thank A. Liang and Z. Wei for help with materials synthesis and B. W. Boudouris for help with electrochemical impedance spectrometry measurements.

Publisher Copyright:
© 2021 Wiley-VCH GmbH


  • charge transfer
  • organic semiconductors
  • perovskite solar cells
  • stability
  • surface passivation

ASJC Scopus subject areas

  • Materials Science (all)
  • Mechanics of Materials
  • Mechanical Engineering


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