Near‐Infrared Electron Acceptors with Fluorinated Regioisomeric Backbone for Highly Efficient Polymer Solar Cells
Abstract
Solar photon‐to‐electron conversion with polymer solar cells (PSCs) has experienced rapid development in the recent few years. Even so, the exploration of molecules and devices in efficiently converting near‐infrared (NIR) photons into electrons remains critical, yet challenging. Herein presented is a family of near‐infrared nonfullerene acceptors (NIR NFAs, T1–T4) with fluorinated regioisomeric A–Aπ–D–Aπ–A backbones for constructing efficient single‐junction and tandem PSCs with photon response up to 1000 nm. It is found that the tuning of the regioisomeric bridge (Aπ) and fluoro (F)‐substituents on a molecular skeleton strongly influences the backbone conformation and conjugation, leading to the optimized optoelectronic and stable stacking of resultant NFAs, which eventually impacts the performance of derived PSCs. In PSCs, the proximal NFAs with varied F‐atoms (T1–T3) mostly outperform than that of distal NFA (T4). Notably, single‐junction PSC with PTB7‐Th:T2 blend can reach 10.87% power conversion efficiency (PCE), after implementing a solvent additive to improve blend morphology. Moreover, efficient tandem PSCs are fabricated through integrating such NIR cells with mediate bandgap nonfullerene‐based subcells, to achieve a PCE of 14.64%. The results reveal the structural design of organic semiconductor and device with improved photovoltaic performance.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 06, 2018
- Source ID
- 10.1002/adma.201803769
Entities
People
- Alex K.‐y. Jen
- Chang-Zhi Li
- Fang‐xiao Chen
- Hin‐lap Yip
- Hongzheng Chen
- Jing‐qi Xu
- Mingwei Chen
- Ruoxi Xia
- Tsz‐ki Lau
- Xinhui Lu
- Yingzhu Zhang
- Yongchao Yang
- Zhi‐xi Liu
Organizations
- City University of Hong Kong
- Ministry of Science and Technology
- National Natural Science Foundation of China
- Office of Naval Research
- South China University of Technology
- The Chinese University of Hong Kong
- University of Washington
- Zhejiang University