Abstract

Efficient wide-bandgap perovskite solar cells (PSCs) enable high-efficiency tandem photovoltaics when combined with crystalline silicon and other low-bandgap absorbers. However, wide-bandgap PSCs today exhibit performance far inferior to that of sub-1.6-eV bandgap PSCs due to their tendency to form a high density of deep traps. Here, we show that healing the deep traps in wide-bandgap perovskites—in effect, increasing the defect tolerance via cation engineering—enables further performance improvements in PSCs. We achieve a stabilized power conversion efficiency of 20.7% for 1.65-eV bandgap PSCs by incorporating dipolar cations, with a high open-circuit voltage of 1.22 V and a fill factor exceeding 80%. We also obtain a stabilized efficiency of 19.1% for 1.74-eV bandgap PSCs with a high open-circuit voltage of 1.25 V. From density functional theory calculations, we find that the presence and reorientation of the dipolar cation in mixed cation–halide perovskites heals the defects that introduce deep trap states.

Details

Title
Dipolar cations confer defect tolerance in wide-bandgap metal halide perovskites
Author
Tan, Hairen 1 ; Che, Fanglin 2 ; Wei, Mingyang 2 ; Zhao, Yicheng 2 ; Saidaminov, Makhsud I 2 ; Todorović, Petar 2 ; Broberg, Danny 3 ; Walters, Grant 2 ; Tan, Furui 4 ; Zhuang, Taotao 2 ; Sun, Bin 2   VIAFID ORCID Logo  ; Liang, Zhiqin 2 ; Yuan, Haifeng 5   VIAFID ORCID Logo  ; Fron, Eduard 6 ; Kim, Junghwan 2 ; Yang, Zhenyu 2   VIAFID ORCID Logo  ; Voznyy, Oleksandr 2   VIAFID ORCID Logo  ; Asta, Mark 3 ; Sargent, Edward H 2   VIAFID ORCID Logo 

1  Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada; National Laboratory of Solid State Microstructures, Collaborative Innovation Centre of Advanced Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, China 
2  Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada 
3  Department of Materials Science and Engineering, University of California, Berkeley, CA, USA; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 
4  Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada; Key Lab of Photovoltaic Materials, Department of Physics and Electronics, Henan University, Kaifeng, China 
5  Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada; Department of Chemistry, KU Leuven, Leuven, Belgium 
6  Department of Chemistry, KU Leuven, Leuven, Belgium 
Pages
1-10
Publication year
2018
Publication date
Aug 2018
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41467-018-05531-8
ProQuest document ID
2084327554
Copyright
© 2018. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.