Geometrically Asymmetric Phosphonium Zwitterions Enable Efficient Printable Mesoscopic Perovskite Solar Cells
Abstract
ABSTRACT Carbon‐based, fully printable hole‐transport‐layer‐free mesoscopic perovskite solar cells (p‐MPSCs) offer a low‐cost, scalable photovoltaic technology, yet suffer from efficiency losses due to non‐radiative recombination at electron‐selective interface. Here, we design geometrically asymmetric zwitterions, featuring a bulky charge‐dispersed triphenylphosphonium cation and a small charge‐concentrated sulfonate anion linked by an alkyl chain, to weaken intermolecular and intramolecular charge attraction, thereby constructing a permanent dipole interlayer that mitigates such recombination. By extending the alkyl spacer and introducing methyl substituents on triphenylphosphonium, the optimized zwitterion, 4‐(tri‐p‐tolylphosphonio)butane‐1‐sulfonate (4MePS), achieves an ultrahigh dipole moment of 14.92 Debye. 4MePS strongly interacts with both perovskite and TiO 2 to form surface dipoles, drastically lowering their work functions by 0.42 and 0.54 eV, respectively. Comprehensive characterizations confirm that 4MePS suppresses non‐radiative recombination and accelerates charge extraction in p‐MPSCs. Consequently, 4MePS‐treated p‐MPSCs deliver a champion power conversion efficiency (PCE) of 23.3% (vs. 21.8% for control) and a minimodule efficiency of 20.2% over 57.3 cm 2 , among the highest reported for p‐MPSCs. Encapsulated devices retain 90% of their initial PCE after 1200 hours of maximum power point tracking under 1‑sun illumination at 55 ± 5 °C. This work establishes a charge density‐asymmetric molecular design strategy for engineering interfacial dipoles toward high‐performance perovskite devices.
Article Details
Authors (12)
Jianhang Qi
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education Huazhong University of Science and Technology Wuhan Hubei China
Yaxin He
Key Laboratory for Material Chemistry of Energy Conversion and Storage (Ministry of Education) Hubei Key Laboratory of Material Chemistry and Service Failure School of Chemistry and Chemical Engineering Huazhong University of Science and Technology Wuhan Hubei China
Jiale Liu
Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University
Yongming Ma
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education Huazhong University of Science and Technology Wuhan Hubei China
Bolun Zhang
Dang Xu
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education Huazhong University of Science and Technology Wuhan Hubei China
Kai Chen
Yang Zhou
Anyi Mei
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education Huazhong University of Science and Technology Wuhan Hubei China
Hin‐Lap Yip
Department of Materials Science and Engineering City University of Hong Kong Kowloon Hong Kong China
Zhong'an Li
Key Laboratory for Material Chemistry of Energy Conversion and Storage (Ministry of Education) Hubei Key Laboratory of Material Chemistry and Service Failure School of Chemistry and Chemical Engineering Huazhong University of Science and Technology (HUST) Wuhan 430074 China
Hongwei Han
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education Huazhong University of Science and Technology Wuhan Hubei China