Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance upgrade on Thursday 4th of May 2017 from 8.00am to 9.00am (BST).

During this time our websites will be offline temporarily. If you have any questions please use the feedback button on this page. We apologise for any inconvenience this might cause and thank you for your patience.



Synergistic Effects of an Alkylthieno[3, 2-b]thiophene π-Bridging Backbone Extension on the Photovoltaic Performances of Donor–acceptor Copolymers

Abstract

The synergistic effects of a thiophene-based π-bridging backbone extension on the intrinsic and photovoltaic properties of electron donor-acceptor (D-A) copolymers were systematically investigated. A series of alternating D-A copolymers (PBTs) based on 4,8-bis(5-ethylhexylselenophen-2-yl)benzo[1,2-b;4,5-b']dithiophene(EHSeBDT) and 5-(2-butyloctyl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (BOTPD), which featured thiophene-based π-bridges, were synthesized: PBT without a π-bridge, PBT with a 3-octylthiophene (OT) π-bridge (PBT-OT), and PBT with a 3-octylthieno[3, 2-b]thiophene (OTT) π-bridge (PBT-OTT). The light absorption and charge transport properties were significantly enhanced upon incorporation of the OTT π-bridge. The enhancements resulted from the strong π-π intermolecular interactions using the OTT π-bridging backbone extension between neighboring polymer chains. PBT-OTT was most miscible in PC71BM. As a result, the photoactive layers prepared using PBT-OTT and PC71BM formed a well-mixed bulk-heterojunction morphology and yielded organic solar cells (OSCs) with a high power conversion efficiency of 7.21%. Transient absorption analysis suggested that the π-electrons were further delocalized along the copolymer after incorporation of the OTT π-bridge, and the charge separation efficiency increased. These results suggested that incorporating OTTπ-bridges into D–A copolymers provides a useful strategy for developing highly efficient OSCs.

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was accepted on 18 Apr 2017 and first published on 18 Apr 2017


Article type: Paper
DOI: 10.1039/C7TA02557B
Citation: J. Mater. Chem. A, 2017, Accepted Manuscript
  •   Request permissions

    Synergistic Effects of an Alkylthieno[3, 2-b]thiophene π-Bridging Backbone Extension on the Photovoltaic Performances of Donor–acceptor Copolymers

    H. Hwang, D. H. Sin, C. Kulshreshtha, B. Moon, J. Son, J. Lee, H. G. Kim, J. Shin, T. Joo and K. Cho, J. Mater. Chem. A, 2017, Accepted Manuscript , DOI: 10.1039/C7TA02557B

Search articles by author