Isoindigo-containing molecular semiconductors: Effect of backbone extension on molecular organization and organic solar cell performance

Yi Ren, Anna K. Hailey, Anna M. Hiszpanski, Yueh Lin Loo

Research output: Contribution to journalArticlepeer-review

24 Scopus citations

Abstract

We have synthesized three new isoindigo-based small molecules by extending the conjugated length through the incorporation of octyl-thiophene units between the isoindigo core and benzothiophene terminal units. Both UV-vis and Grazing incidence X-ray diffraction experiments show that such extension of the π-conjugated backbone can induce H-aggregation, and enhance crystallinity and molecular ordering of these isoindigo-based small molecules in the solid state. Compared to two other isoindigo-based derivatives in the series, the derivative with two octyl-thiophene units, BT-T2-ID, is the most crystalline and ordered, and its molecular packing motif appears to be substantially different. Devices utilizing these new extended isoindigo-based small molecules as the electron donor exhibit higher performance than those utilizing nonextended BT-ID as the electron donor. Particularly, devices containing BT-T2-ID in an as-cast blend with PC61BM show power conversion efficiencies up to 3.4%, which is comparable to the best devices containing isoindigo-based molecular semiconductors and is a record among devices containing isoindigo-based small molecules that were processed in the absence of any additives.

Original languageEnglish (US)
Pages (from-to)6570-6577
Number of pages8
JournalChemistry of Materials
Volume26
Issue number22
DOIs
StatePublished - Nov 25 2014

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Isoindigo-containing molecular semiconductors: Effect of backbone extension on molecular organization and organic solar cell performance'. Together they form a unique fingerprint.

Cite this