1. Dopant-free hole-transporting materials featuring intramolecular π-π interactions for efficient and stable perovskite solar cells.
- Author
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Gai, Xiaofan, Bao, Huayu, Gu, Cancan, Zhang, Zhenhu, Li, Jianye, Cao, Xiaohui, Wang, Shirong, Li, Xianggao, and Yin, Guohui
- Subjects
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SOLAR cells , *MOLECULAR shapes , *PEROVSKITE , *HOLE mobility , *PRODUCTION sharing contracts (Oil & gas) , *MOLECULAR interactions , *INTRAMOLECULAR catalysis - Abstract
[Display omitted] • A new strategy of developing high-performance dopant-free HTMs for PSCs is presented. • Two novel HTMs with intramolecular π-π interactions were developed for PSCs. • Crystal structures offer information on molecular configuration and interactions. • PSCs based on BFM-C6 showed a PCE of 19.06% with enhanced long-term stability. The development of hole-transporting materials (HTMs), especially dopant-free ones, is of great significance for simultaneously improving the efficiency and stability of perovskite solar cells (PSCs). Herein, two molecularly engineered HTMs (BFM-C1 and BFM-C6) featuring intramolecular π-π interactions are designed based on the well-known spiro-OMeTAD and synthesized via simple synthetic routes. Unlike the spiro-OMeTAD with orthogonal conformation, both BFM-C1 and BFM-C6 are revealed to adopt a "face-to-face" stacking orientation with evident intramolecular π-π interactions, and display about five times higher hole mobilities (≈ 10-4 cm2V-1s−1) than pristine spiro-OMeTAD. Moreover, both the HTMs exhibit high hole extraction capacity likely owing to good electronic contact with the perovskite. Notably, the incorporated long alkyl chains endow BFM-C6 with better film morphology and superior hydrophobicity, as compared with BFM-C1 , thereby resulting in enhanced charge extraction at the perovskite/HTM interface as well as the moisture stability of the perovskite underneath. Consequently, the PSCs employing BFM-C6 as HTM without dopants achieve a power conversion efficiency of 19.06%, along with preferable durability. Furthermore, BFM-C6 -based PSCs also exhibit improved thermal stability as compared to the devices based on doped spiro-OMeTAD. This work not only enriches the variety of dopant-free HTMs for PSCs, but also provide a new strategy for developing high-performance dopant-free HTMs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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