Dopant-Free Bithiophene-Imide-Based Polymeric Hole-Transporting Materials for Efficient and Stable Perovskite Solar Cells

Bai Y, Zhou Z, Xue Q, Liu C, Li N, Tang H, Zhang J, Xia X, Zhang J, Lu X, Brabec C, Huang F (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Advanced Materials Wiley

DOI: 10.1002/adma.202110587

Abstract

The development of hole-transport materials (HTMs) with high mobility, long-term stability, and comprehensive passivation is significant for simultaneously improving the efficiency and stability of perovskite solar cells (PVSCs). Herein, two donor-acceptor (D-A) conjugated polymers PBTI and PFBTI with alternating benzodithiophene (BDT) and bithiophene imide (BTI) units are successfully developed with desirable hole mobilities due to the good planarity and extended conjugation of molecular backbone. Both copolymers can be employed as HTMs with suitable energy levels and efficient defect passivation. Shortening the alkyl chain of the BTI unit and introducing fluorine atoms on the BDT moiety effectively enhances hole mobility and hydrophobicity of the HTMs, leading to improved efficiency and stability of PVSCs. As a result, the organic-inorganic hybrid PVSCs with PFBTI as the HTM deliver a power conversion efficiency (PCE) of 23.1% with enhanced long-term operational and ambient stability, which is one of the best efficiencies reported for PVSCs with dopant-free polymeric HTMs to date. Moreover, PFBTI can be applied in inorganic PVSCs and perovskite/organic tandem solar cells, achieving a high PCE of 17.4% and 22.2%, respectively. These results illustrate the great potential of PFBTI as an efficient and widely applicable HTM for cost-effective and stable PVSCs.

Authors with CRIS profile

Christoph Brabec Institute Materials for Electronics and Energy Technology (i-MEET) (i-MEET)

Involved external institutions

South China University of Technology (SCUT) / 华南理工大学 CN China (CN) The Chinese University of Hong Kong (CUHK) CN China (CN)

How to cite

APA:

Bai, Y., Zhou, Z., Xue, Q., Liu, C., Li, N., Tang, H.,... Huang, F. (2022). Dopant-Free Bithiophene-Imide-Based Polymeric Hole-Transporting Materials for Efficient and Stable Perovskite Solar Cells. Advanced Materials. https://doi.org/10.1002/adma.202110587

MLA:

Bai, Yuanqing, et al. "Dopant-Free Bithiophene-Imide-Based Polymeric Hole-Transporting Materials for Efficient and Stable Perovskite Solar Cells." Advanced Materials (2022).

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