Conjugated Polymer–Assisted Grain Boundary Passivation for Efficient Inverted Planar Perovskite Solar Cells

Wei Chen, Yingfeng Wang, Guotao Pang, Chang Woo Koh, Aleksandra B. Djurišić, Yinghui Wu, Bao Tu, Fang zhou Liu, Rui Chen, Han Young Woo, Xugang Guo, Zhubing He

Research output: Contribution to journalArticlepeer-review

135 Citations (Scopus)


Grain boundaries in lead halide perovskite films lead to increased recombination losses and decreased device stability under illumination due to defect-mediated ion migration. The effect of a conjugated polymer additive, poly(bithiophene imide) (PBTI), is investigated in the antisolvent treatment step in the perovskite film deposition by comprehensive characterization of perovskite film properties and the performance of inverted planar perovskite solar cells (PSCs). PBTI is found to be incorporated within grain boundaries, which results in an improvement in perovskite film crystallinity and reduced defects. The successful defect passivation by PBTI yields reduces recombination losses and consequently increases power conversion efficiency (PCE). In addition, it gives rise to improved photoluminescence stability and improved PSC stability under illumination which can be attributed to reduced ion migration. The optimal devices exhibit a PCE of 20.67% compared to 18.89% of control devices without PBTI, while they retain over 70% of the initial efficiency after 600 h under 1 sun illumination compared to 56% for the control devices.

Original languageEnglish
Article number1808855
JournalAdvanced Functional Materials
Issue number27
Publication statusPublished - 2019 Jul 4

Bibliographical note

Funding Information:
W.C., Y.W. and G.P. contributed equally to this work. This work was supported by the National Natural Science Foundation of China (NSFC) (Nos. 61775091 and 51573076), National Key Research Project MOST (No. 2016YFA0202400), the Shenzhen Key Laboratory Project (No. ZDSYS201602261933302), and Natural Science Foundation of Shenzhen Innovation Committee (Nos. JCYJ20180504165851864, JCYJ20170818141216288, JCYJ20170817105905899). The authors are grateful for support from the Seed Funding for Strategic Interdisciplinary Research Scheme of the University of Hong Kong. RGC GRF grants 15204515 and 15246816 are also acknowledged. The authors thank the Materials Characterization and Preparation Center (MCPC) and the Pico Center of SUSTech for some characterizations in this work.

Publisher Copyright:
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • conjugated polymers
  • grain boundary passivation
  • halide perovskites
  • nickel oxide

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • General Chemistry
  • General Materials Science
  • Electrochemistry
  • Biomaterials


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