Graded 2D/3D Perovskite Heterostructure for Efficient and Operationally Stable MA-Free Perovskite Solar Cells

Qin Yao; Qifan Xue; Zhenchao Li; Kaicheng Zhang; Teng Zhang; Ning Li; Shihe Yang; Christoph J Brabec; Hin-Lap Yip; Yong Cao

doi:10.1002/adma.202000571

Graded 2D/3D Perovskite Heterostructure for Efficient and Operationally Stable MA-Free Perovskite Solar Cells

Adv Mater. 2020 Jul;32(26):e2000571. doi: 10.1002/adma.202000571. Epub 2020 May 25.

Authors

Qin Yao¹, Qifan Xue^{1

2}, Zhenchao Li¹, Kaicheng Zhang³, Teng Zhang⁴, Ning Li^{3

5}, Shihe Yang^{4

6}, Christoph J Brabec³, Hin-Lap Yip^{1

2}, Yong Cao¹

Affiliations

¹ State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, School of Materials Science and Engineering, South China University of Technology, 381 Wushan Road, Guangzhou, 510640, P. R. China.
² Innovation Center of Printed Photovoltaics, South China Institute of Collaborative Innovation, Dongguan, 523808, P. R. China.
³ Institute of Materials for Electronics and Energy Technology (i-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, Martensstraße 7, Erlangen, 91058, Germany.
⁴ Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077, P. R. China.
⁵ National Engineering Research Center for Advanced Polymer Processing Technology, Zhengzhou University, Zhengzhou, 450002, P. R. China.
⁶ Guangdong Key Lab of Nano-Micro Material Research, School of Chemical Biology and Biotechnology, Shenzhen Graduate School, Peking University, Xili University Town, Shenzhen, 518055, P. R. China.

PMID: 32449209
DOI: 10.1002/adma.202000571

Abstract

Almost all highly efficient perovskite solar cells (PVSCs) with power conversion efficiencies (PCEs) of greater than 22% currently contain the thermally unstable methylammonium (MA) molecule. MA-free perovskites are an intrinsically more stable optoelectronic material for use in solar cells but compromise the performance of PVSCs with relatively large energy loss. Here, the open-circuit voltage (V_oc ) deficit is circumvented by the incorporation of β-guanidinopropionic acid (β-GUA) molecules into an MA-free bulk perovskite, which facilitates the formation of quasi-2D structure with face-on orientation. The 2D/3D hybrid perovskites embed at the grain boundaries of the 3D bulk perovskites and are distributed through half the thickness of the film, which effectively passivates defects and minimizes energy loss of the PVSCs through reduced charge recombination rates and enhanced charge extraction efficiencies. A PCE of 22.2% (certified efficiency of 21.5%) is achieved and the operational stability of the MA-free PVSCs is improved.

Keywords: 2D/3D heterostructures; MA-free perovskite solar cells; ambient stability; energy loss; high efficiency.

Abstract

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