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A Simple Way to Simultaneously Release the Interface Stress and Realize the Inner Encapsulation for Highly Efficient and Stable Perovskite Solar Cells
Author(s) -
Wu Jionghua,
Cui Yuqi,
Yu Bingchen,
Liu Kuan,
Li Yiming,
Li Hongshi,
Shi Jiangjian,
Wu Huijue,
Luo Yanhong,
Li Dongmei,
Meng Qingbo
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201905336
Subject(s) - materials science , perovskite (structure) , energy conversion efficiency , perovskite solar cell , annealing (glass) , photoelectric effect , optoelectronics , halide , solar cell , polystyrene , residual stress , nanotechnology , chemical engineering , composite material , inorganic chemistry , chemistry , engineering , polymer
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 SnO 2 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.