A Facile Method to Enhance Photovoltaic Performance of Benzodithiophene-Isoindigo Polymers by Inserting Bithiophene Spacer
Journal article, 2014

This study describes the synthesis and characterization of four polymers based on benzo[1,2-b:4,5-b']dithiophene (BDT) and isoindigo with zero, one, two, and three thiophene spacer groups. Results have demonstrated that the use of bithiophene as a spacer unit improves the geometry of the polymer chain, making it planar, and hence, potentially enhanced π- π stacking occurs. Due to favorable interaction of the polymer chains, enhanced absorption coefficient, and optimal morphology, PBDT-BTI, which possesses bithiophene as a spacer, revealed high current and fill factor leading to a power conversion efficiency of 7.3% in devices, making this polymer the best performing isoindigo-based material in polymer solar cells (PSCs). Also, PBDT-BTI could still maintain efficiency of over 6% with the active layer thickness of 270 nm, making it a potential candidate for a material in printed PSCs. These results demonstrate that the use of thiophene spacers in D-A polymers could be an important design strategy to produce high-performance PSCs.

energy conversion


solar cells


conjugated polymers


Z. F. Ma

Linköping University

Dongfeng Dang

Chalmers, Chemical and Biological Engineering, Polymer Technology

Z. Tang

Linköping University

Desta Antenehe Gedefaw

Chalmers, Chemical and Biological Engineering, Polymer Technology

J. Bergqvist

Linköping University

Weiguo Zhu

Xiangtan University

Wendimagegn Mammo

Addis Ababa University

Mats Andersson

Chalmers, Chemical and Biological Engineering, Polymer Technology

Olle Inganäs

Linköping University

Fengling Zhang

Linköping University

Ergang Wang

Chalmers, Chemical and Biological Engineering, Polymer Technology

Advanced Energy Materials

1614-6832 (ISSN) 1614-6840 (eISSN)

Vol. 4 6 Art. no. 1301455- 1301455

Areas of Advance

Nanoscience and Nanotechnology


Materials Science

Subject Categories

Materials Engineering

Chemical Engineering

Chemical Sciences



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