A Simple Way to Simultaneously Release the Interface Stress and Realize the Inner Encapsulation for Highly Efficient and Stable Perovskite Solar Cells

Jionghua Wu, Yuqi Cui, Bingchen Yu, Kuan Liu, Yiming Li, Hongshi Li, Jiangjian Shi, Huijue Wu, Yanhong Luo, Dongmei Li, Qingbo Meng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

41 Citations (Scopus)


The mixed halide perovskites have become famous for their outstanding photoelectric conversion efficiency among new-generation solar cells. Unfortunately, for perovskites, little effort is focused on stress engineering, which should be emphasized for highly efficient solar cells like GaAs. Herein, polystyrene (PS) is introduced into the perovskite solar cells as the buffer layer between the SnO2 and perovskite, which can release the residual stress in the perovskite during annealing because of its low glass transition temperature. The stress-free perovskite has less recombination, larger lattices, and a lower ion migration tendency, which significantly improves the cell's efficiency and device stability. Furthermore, the so-called inner-encapsulated perovskite solar cells are fabricated with another PS capping layer on the top of perovskite. As high as a 21.89% photoelectric conversion efficiency (PCE) with a steady-state PCE of 21.5% is achieved, suggesting that the stress-free cell can retain almost 97% of its initial efficiency after 5 days of “day cycle” stability testing.

Original languageEnglish
Article number1905336
JournalAdvanced Functional Materials
Issue number49
Publication statusPublished - 1 Dec 2019


  • inner encapsulation
  • perovskites
  • polystyrene
  • solar cells

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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