5 years ago

Asymmetric Alkyl Side-Chain Engineering of Naphthalene Diimide-Based n-Type Polymers for Efficient All-Polymer Solar Cells

Asymmetric Alkyl Side-Chain Engineering of Naphthalene Diimide-Based n-Type Polymers for Efficient All-Polymer Solar Cells
Baobing Fan, Zhenye Li, Tao Jia, Yong Cao, Jianchao Jia, Wenkai Zhong, Feilong Pan, Junwu Chen, Penghui He, Fei Huang, Lei Ying
The design and synthesis of three n-type conjugated polymers based on a naphthalene diimide–thiophene skeleton are presented. The control polymer, PNDI-2HD, has two identical 2-hexyldecyl side chains, and the other polymers have different alkyl side chains; PNDI-EHDT has a 2-ethylhexyl and a 2-decyltetradecyl side chain, and PNDI-BOOD has a 2-butyloctyl and a 2-octyldodecyl side chain. These copolymers with different alkyl side chains exhibit higher melting and crystallization temperatures, and stronger aggregation in solution, than the control copolymer PNDI-2HD that has the same side chain. Polymer solar cells based on the electron-donating copolymer PTB7-Th and these novel copolymers exhibit nearly the same open-circuit voltage of 0.77 V. Devices based on the copolymer PNDI-BOOD with different side chains have a power-conversion efficiency of up to 6.89%, which is much higher than the 4.30% obtained with the symmetric PNDI-2HD. This improvement can be attributed to the improved charge-carrier mobility and the formation of favorable film morphology. These observations suggest that the molecular design strategy of incorporating different side chains can provide a new and promising approach to developing n-type conjugated polymers. Three n-type conjugated polymers based on a naphthalene diimide–thiophene skeleton and different alkyl side chains are designed and synthesized. Polymer solar cells based on the copolymer PNDI-BOOD with different side chains exhibit an improved power-conversion efficiency of 6.89%, which can be attributed to the improved charge-carrier mobility and the formation of favorable film morphology.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/marc.201700765

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.