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Stable and Efficient Organo‐Metal Halide Hybrid Perovskite Solar Cells via π‐Conjugated Lewis Base Polymer Induced Trap Passivation and Charge Extraction
Author(s) -
Qin PingLi,
Yang Guang,
Ren Zhiwei,
Cheung Sin Hang,
So Shu Kong,
Chen Li,
Hao Jianhua,
Hou Jianhui,
Li Gang
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201706126
Subject(s) - materials science , perovskite (structure) , passivation , energy conversion efficiency , chemical engineering , polymer , polymer chemistry , nanotechnology , layer (electronics) , optoelectronics , engineering , composite material
High‐quality pinhole‐free perovskite film with optimal crystalline morphology is critical for achieving high‐efficiency and high‐stability perovskite solar cells (PSCs). In this study, a p‐type π‐conjugated polymer poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl) thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′] dithiophene))‐ alt ‐(5,5‐(1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethylhexyl) benzo[1′,2′‐c:4′,5′‐c′] dithiophene‐4,8‐dione))] (PBDB‐T) is introduced into chlorobenzene to form a facile and effective template‐agent during the anti‐solvent process of perovskite film formation. The π‐conjugated polymer PBDB‐T is found to trigger a heterogeneous nucleation over the perovskite precursor film and passivate the trap states of the mixed perovskite film through the formation of Lewis adducts between lead and oxygen atom in PBDB‐T. The p‐type semiconducting and hydrophobic PBDB‐T polymer fills in the perovskite grain boundaries to improve charge transfer for better conductivity and prevent moisture invasion into the perovskite active layers. Consequently, the PSCs with PBDB‐T modified anti‐solvent processing leads to a high‐efficiency close to 20%, and the devices show excellent stability, retaining about 90% of the initial power conversion efficiency after 150 d storage in dry air.