Efficient and Stable FASnI3 Perovskite Solar Cells with Effective Interface Modulation by Low-Dimensional Perovskite Layer

Min Liao; Bin-Bin Yu; Zhixin Jin; Wei Chen; Yudong Zhu; Xusheng Zhang; Weitang Yao; Tao Duan; Igor Djerdj; Zhubing He

doi:10.1002/cssc.201902000

Efficient and Stable FASnI₃ Perovskite Solar Cells with Effective Interface Modulation by Low-Dimensional Perovskite Layer

ChemSusChem. 2019 Nov 22;12(22):5007-5014. doi: 10.1002/cssc.201902000. Epub 2019 Oct 11.

Authors

Min Liao^{1

2}, Bin-Bin Yu^{2

3}, Zhixin Jin², Wei Chen², Yudong Zhu², Xusheng Zhang², Weitang Yao¹, Tao Duan¹, Igor Djerdj⁴, Zhubing He²

Affiliations

¹ State Key Laboratory of Environment-Friendly Energy Materials, School of National Defense Science & Technology, Southwest University of Science and Technology, Mianyang, 621010, P.R. China.
² Department of Materials Science and Engineering, Shenzhen Key Laboratory of Full Spectral Solar Electricity Generation (FSSEG), Southern University of Science and Technology, No. 1088, Xueyuan Rd., Shenzhen, 518055, Guangdong, P.R. China.
³ Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, P.R. China.
⁴ Department of Chemistry, Josip Juraj Strossmayer University of Osijek, Cara Hadrijana 8-A, HR-31000, Osijek, Croatia.

PMID: 31468722
DOI: 10.1002/cssc.201902000

Abstract

The promising tin perovskite solar cells (PSCs) suffer from the oxidation of Sn²⁺ to Sn⁴⁺ , leading to a disappointing conversion efficiency along with poor stability. In this work, phenylethylammonium bromide (PEABr) was employed to form an ultrathin, low-dimensional perovskite layer on the surface of the FASnI₃ (FA=formamidinium) absorber film to improve the interface of perovskite/PCBM ([6,6]-phenyl-C₆₁ -butyricacid methyl) in the inverted planar device structure of the ITO (indium-doped tin oxide)/PEDOT:PSS [poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate]/perovskite/[6,6]-phenyl-C₆₁ -butyricacid methyl (PCBM)/BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) electrode. The device efficiency was enhanced from 4.77 to 7.86 % by this PEABr treatment. A series of characterizations proved that this modification could improve the crystallinity of the FASnI₃ perovskite by incorporating Br and forming an ultrathin, low-dimensional perovskite layer at the interface, which led to the effective suppression of Sn²⁺ oxidation, improved band level alignment, and decreased defect density. These effects contributed to the clear enhancement of conversion efficiency. Moreover, this treatment also led to remarkably enhanced device stability, with approximately 80 % of the initial efficiency retained after 350 h light soaking, whereas the control device failed within 140 h. This work deepens our understanding of the suppression effect of PEABr on the oxidation of Sn²⁺ and paves a new way to fabricate promising tin halide PSCs by facile interface engineering.

Keywords: interface engineering; low-dimensional layer; phenylethylammonium bromide; solar cells; tin perovskite.

Abstract

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