Surface Passivation and Energy Alignment Modulation of n-i-p Perovskite Solar Cells with Self-Assembled Molecule

Yuyan Dong; Ligang Yuan; Linhui Tang; Zheng Zhang; Shibing Zou; Jianwei Chen; Xin Cui; Ning Li; Lei Shi; Keyou Yan

doi:10.1002/smll.202412628

Surface Passivation and Energy Alignment Modulation of n-i-p Perovskite Solar Cells with Self-Assembled Molecule

Small. 2025 May;21(21):e2412628. doi: 10.1002/smll.202412628. Epub 2025 Apr 3.

Authors

Yuyan Dong¹, Ligang Yuan², Linhui Tang², Zheng Zhang¹, Shibing Zou¹, Jianwei Chen¹, Xin Cui¹, Ning Li¹, Lei Shi³, Keyou Yan¹

Affiliations

¹ School of Environment and Energy, State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, AIE Institute, South China University of Technology, Guangzhou, 510000, P. R. China.
² Key Laboratory for Optoelectronic Information Perception and Instrumentation of Jiangxi Province Key Laboratory of Nondestructive Testing Ministry of Education School of the Testing and Photoelectric Engineering Nanchang Hangkong University Nanchang, Nanchang, 330063, P. R. China.
³ Hangzhou Zhongneng Optoelectronics Technology Co., Ltd, Hangzhou, 310000, P. R. China.

PMID: 40178014
DOI: 10.1002/smll.202412628

Abstract

Perovskite's surface defects trigger deep level traps and energy misalignment, resulting in substantial interface recombination and energy loss in perovskite solar cells (PSCs). Herein, 9-fluoreneacetic acid (FAA), a self-assembled molecule (SAM), is employed to passivate the interface defects and modulate energy alignment. SAM modification reduces the defect density from 6.37 × 10¹⁵ to 3.11 × 10¹⁵ cm^-3 and produces a p-type surface with an upward band bending, thus constructing a well-defined n-i-p heterojunction for efficient charge separation. Accordingly, the target PSC realizes 24.75% power conversion efficiency (PCE) and retains 92% for 1100 h during maximum power point tracking (MPPT) at room temperature. Furthermore, over 80% of initial PCE has been reserved after 2500 h aging in 25-30% relative humidity (RH). This SAM strategy is expected to enhance the efficiency and stability for n-i-p PSCs.

Keywords: 9‐fluoreneacetic acid; energy level alignment; perovskite solar cells; stability; surface passivation.

Abstract

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