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Biselenophene Imide: Enabling Polymer Acceptor with High Electron Mobility for High-Performance All-Polymer Solar Cells |
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| Authors: | Suxiang Ma Bangbang Li Shaokuan Gong Junwei Wang Dr. Bin Liu Sang Young Jeong Prof. Xihan Chen Prof. Han Young Woo Dr. Kui Feng Prof. Xugang Guo |
| Affiliation: | 1. Department of Materials Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055 China Contribution: Formal analysis (lead), Investigation (lead), Writing - original draft (lead);2. Department of Materials Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055 China Contribution: Investigation (equal);3. Department of Mechanical and Energy Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055 China Contribution: Investigation (supporting);4. Department of Materials Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055 China Contribution: Investigation (supporting);5. Department of Chemistry, Korea University, Seoul, 136-713 South Korea Contribution: Investigation (supporting);6. Department of Materials Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055 China |
| Abstract: | The shortage of narrow band gap polymer acceptors with high electron mobility is the major bottleneck for developing efficient all-polymer solar cells (all-PSCs). Herein, we synthesize a distannylated electron-deficient biselenophene imide monomer (BSeI-Tin) with high purity/reactivity, affording an excellent chance to access acceptor–acceptor (A–A) type polymer acceptors. Copolymerizing BSeI-Tin with dibrominated monomer Y5-Br, the resulting A–A polymer PY5-BSeI shows a higher molecular weight, narrower band gap, deeper-lying frontier molecular orbital levels and larger electron mobility than the donor–acceptor type counterpart PY5-BSe. Consequently, the PY5-BSeI-based all-PSCs deliver a remarkable efficiency of 17.77 % with a high short-circuit current of 24.93 mA cm−2 and fill factor of 75.83 %. This efficiency is much higher than that (10.70 %) of the PY5-BSe-based devices. Our study demonstrates that BSeI is a promising building block for constructing high-performance polymer acceptors and stannylation of electron-deficient building blocks offers an excellent approach to developing A–A type polymers for all-PSCs and even beyond. |
| Keywords: | Acceptor Acceptor-Acceptor Backbone Narrow Bandgap Polymer Solar Cells |