Anchorable Polymers Enabling Ultra-Thin and Robust Hole-Transporting Layers for High-Efficiency Inverted Perovskite Solar Cells

Liqing Zhan; Shuo Zhang; Zhihao Li; Wenzhuo Li; Huidong Zhang; Jingwen He; Xiaoyu Ji; Shuaijun Liu; Furong Yu; Songran Wang; Zhijun Ning; Zhen Li; Martin Stolterfoht; Liyuan Han; Wei-Hong Zhu; Yisheng Xu; Yongzhen Wu

doi:10.1002/anie.202422571

Anchorable Polymers Enabling Ultra-Thin and Robust Hole-Transporting Layers for High-Efficiency Inverted Perovskite Solar Cells

Angew Chem Int Ed Engl. 2025 Jan 9:e202422571. doi: 10.1002/anie.202422571. Online ahead of print.

Authors

Liqing Zhan¹, Shuo Zhang^{1

2}, Zhihao Li³, Wenzhuo Li⁴, Huidong Zhang¹, Jingwen He¹, Xiaoyu Ji¹, Shuaijun Liu¹, Furong Yu¹, Songran Wang¹, Zhijun Ning⁴, Zhen Li³, Martin Stolterfoht⁵, Liyuan Han⁶, Wei-Hong Zhu^{1

2}, Yisheng Xu⁷, Yongzhen Wu^{1

2}

Affiliations

¹ Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Shanghai Key Laboratory of Functional Materials Chemistry, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China.
² Center of Photosensitive Chemicals Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China.
³ School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, China.
⁴ School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.
⁵ Electronic Engineering Department, The Chinese University of Hong Kong, Hong Kong SAR, China.
⁶ School of Material Science and Engineering, Shanghai Jiao Tong University, Shanghai, China.
⁷ State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, School of Chemical Engineering, State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China.

PMID: 39780690
DOI: 10.1002/anie.202422571

Abstract

Currently, the development of polymeric hole-transporting materials (HTMs) lags behind that of small-molecule HTMs in inverted perovskite solar cells (PSCs). A critical challenge is that conventional polymeric HTMs are incapable of forming ultra-thin and conformal coatings like self-assembly monolayers (SAMs), especially for substrates with rough surface morphology. Herein, we address this challenge by designing anchorable polymeric HTMs (CP1 to CP5). Specifically, coordinative pyridyl groups are introduced as side-chains on poly-triarylamine (PTAA) backbone with varied contents by copolymerization method, resulting in chemical interactions between polymeric HTMs and substrates. The strong interaction allows them to be processed into ultra-thin, uniform, and robust hole-transporting layers through employing low-concentration solutions (0.1 mg mL^-1, vs. 2.0-5.0 mg mL^-1 for conventional PTAA), greatly decreasing charge transport losses. Moreover, upon systematically tuning the pyridyl substitution ratio, the energy levels, surface wetting, solution processability, and defect passivation capability of such anchorable HTMs are simultaneously optimized. Based on the optimal CP4, we achieved highly efficient inverted PSCs with power conversion efficiencies (PCEs) up to 26.21 %, which is on par with state-of-the-art SAM-based inverted PSCs. Furthermore, these devices exhibit enhanced stabilities under repeated current-voltage scans and reverse bias ageing compared with SAM-based devices.

Keywords: Interfacial Anchoring; Inverted Perovskite Solar Cells; Polymeric Hole-Transporting Materials; Ultra-Thin Films.

Abstract

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