Triptycene-trisaroyleneimidazoles as non-fullerene acceptors – Influence of side-chains on solubility, device morphology and performance

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Elisabeth H. Menke - , Heidelberg University  (Author)
  • David Leibold - , Heidelberg University  (Author)
  • Vincent Lami - , Heidelberg University  (Author)
  • Yvonne J. Hofstetter - , Heidelberg University  (Author)
  • Michael Mastalerz - , Heidelberg University  (Author)
  • Yana Vaynzof - , Heidelberg University  (Author)

Abstract

The use of non-fullerene acceptors in bulk heterojunction organic solar cells offers the possibility of complementary absorption, adjustment of the electronic energy levels and improved stability and performance. Triptycene-trisaroyleneimidazoles (TTAI) represent a new class of three dimensional acceptor molecules with great promise for application in organic photovoltaic devices. We synthesized six TTAI derivatives in which the molecular symmetry and solubility are varied. We show that these changes do not affect the optoelectronic properties of the acceptor molecules, but have a profound effect on their performance in photovoltaic devices. Enhancing the solubility of the TTAI acceptors to match that of the donor polymer PTB7 resulted in an improved blend phase separation, evident from an enhanced open circuit voltage of 0.9 V and a doubling of the short circuit current as compared to derivatives with lower solubility. A maximum power conversion efficiency of 3.2% was obtained for TTAI with ethylhexyl side chains, demonstrating the potential of TTAI derivatives as electron acceptors.

Details

Original languageEnglish
Pages (from-to)211-219
Number of pages9
JournalOrganic electronics
Volume47
Publication statusPublished - 1 Aug 2017
Peer-reviewedYes
Externally publishedYes

Keywords

Sustainable Development Goals

Keywords

  • Non-fullerene acceptors, Organic photovoltaic devices, Triptycene-trisaroyleneimidazole