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Effect of High Dipole Moment Cation on Layered 2D Organic–Inorganic Halide Perovskite Solar Cells
Author(s) -
Tan Shunquan,
Zhou Ning,
Chen Yihua,
Li Liang,
Liu Guilin,
Liu Pengfei,
Zhu Cheng,
Lu Jiuzhou,
Sun Wentao,
Chen Qi,
Zhou Huanping
Publication year - 2019
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201803024
Subject(s) - perovskite (structure) , materials science , energy conversion efficiency , halide , dipole , organic solar cell , electronegativity , photovoltaic system , optoelectronics , inorganic chemistry , crystallography , chemistry , organic chemistry , composite material , polymer , ecology , biology
Layered 2D organic–inorganic hybrid perovskite is appearing as a rising star in the photovoltaic field, thanks to its superior moisture resistance by the organic spacer cations. Unfortunately, these cations lead to high exciton binding energy in the 2D perovskites, which suffers from lower efficiency in the devices. It thus requires a clear criterion to select/design appropriate organic spacer cations to improve the device efficiency based on this class of materials. Here, 2,2,2‐trifluoroethylamine (F 3 EA + ) is introduced to combine with butylammonium (BA + ) cations as mixed spacers. While BA + enables self‐assembly of 2D perovskite crystals by van der Waals interaction, the introduction of F 3 EA + spacers with a high dipole moment suppress nonradiative recombination and promote separation of photogenerated electron–hole pairs by taking the advantage of electronegativity of fluorine. The resultant solar cells based on [(BA) 1– x (F 3 EA) x ] 2 (MA) 3 Pb 4 I 13 exhibit substantially increased open circuit voltage and fill factor compared with that of (BA) 2 (MA) 3 Pb 4 I 13 . The champion [(BA) 0.94 (F 3 EA) 0.06 ] 2 (MA) 3 Pb 4 I 13 solar cell yields a power conversion efficiency of 12.51%, which is among the best performances so far. These findings suggest an effective strategy to design organic spacer cations in layered perovskite for solar cells and other optoelectronic applications.