TY - JOUR
T1 - Cation and anion immobilization through chemical bonding enhancement with fluorides for stable halide perovskite solar cells
AU - Li, Nengxu
AU - Tao, Shuxia
AU - Chen, Yihua
AU - Niu, Xiuxiu
AU - Onwudinanti, Chidozie K.
AU - Hu, Chen
AU - Qiu, Zhiwen
AU - Xu, Ziqi
AU - Zheng, Guanhaojie
AU - Wang, Ligang
AU - Zhang, Yu
AU - Li, Liang
AU - Liu, Huifen
AU - Lun, Yingzhuo
AU - Hong, Jiawang
AU - Wang, Xueyun
AU - Liu, Yuquan
AU - Xie, Haipeng
AU - Gao, Yongli
AU - Bai, Yang
AU - Yang, Shihe
AU - Brocks, Geert
AU - Chen, Qi
AU - Zhou, Huanping
N1 - Publisher Copyright:
© 2019, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - Defects play an important role in the degradation processes of hybrid halide perovskite absorbers, impeding their application for solar cells. Among all defects, halide anion and organic cation vacancies are ubiquitous, promoting ion diffusion and leading to thin-film decomposition at surfaces and grain boundaries. Here, we employ fluoride to simultaneously passivate both anion and cation vacancies, by taking advantage of the extremely high electronegativity of fluoride. We obtain a power conversion efficiency of 21.46% (and a certified 21.3%-efficient cell) in a device based on the caesium, methylammonium (MA) and formamidinium (FA) triple-cation perovskite (Cs0.05FA0.54MA0.41)Pb(I0.98Br0.02)3 treated with sodium fluoride. The device retains 90% of its original power conversion efficiency after 1,000 h of operation at the maximum power point. With the help of first-principles density functional theory calculations, we argue that the fluoride ions suppress the formation of halide anion and organic cation vacancies, through a unique strengthening of the chemical bonds with the surrounding lead and organic cations.
AB - Defects play an important role in the degradation processes of hybrid halide perovskite absorbers, impeding their application for solar cells. Among all defects, halide anion and organic cation vacancies are ubiquitous, promoting ion diffusion and leading to thin-film decomposition at surfaces and grain boundaries. Here, we employ fluoride to simultaneously passivate both anion and cation vacancies, by taking advantage of the extremely high electronegativity of fluoride. We obtain a power conversion efficiency of 21.46% (and a certified 21.3%-efficient cell) in a device based on the caesium, methylammonium (MA) and formamidinium (FA) triple-cation perovskite (Cs0.05FA0.54MA0.41)Pb(I0.98Br0.02)3 treated with sodium fluoride. The device retains 90% of its original power conversion efficiency after 1,000 h of operation at the maximum power point. With the help of first-principles density functional theory calculations, we argue that the fluoride ions suppress the formation of halide anion and organic cation vacancies, through a unique strengthening of the chemical bonds with the surrounding lead and organic cations.
UR - http://www.scopus.com/inward/record.url?scp=85065773865&partnerID=8YFLogxK
U2 - 10.1038/s41560-019-0382-6
DO - 10.1038/s41560-019-0382-6
M3 - Article
AN - SCOPUS:85065773865
SN - 2058-7546
VL - 4
SP - 408
EP - 415
JO - Nature Energy
JF - Nature Energy
IS - 5
ER -
