Journal article

Effect of Side-Chain Modification on the Active Layer Morphology and Photovoltaic Performance of Liquid Crystalline Molecular Materials

Jegadesan Subbiah, Calvin J Lee, Valerie D Mitchell, David J Jones



Controlling the nanoscale morphology of the photoactive layer by fine-tuning the molecular structure of semiconducting organic materials is one of the most effective ways to improve the power conversion efficiency of organic solar cells. In this contribution, we investigate the photovoltaic performance of benzodithiophene (BDT)-based p-type small molecules with three different side chains, namely alkyl-thio (BTR-TE), dialkylthienyl (BTR), and trialkylsilyl (BTR-TIPS) moieties substituted on the BDT core, when used alongside a nonfullerene acceptor. The side-chain changes on the BDT core are shown to have a profound effect on energy levels, charge generation, recombination, morphology, and ph..

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Funding Acknowledgements

J.S., C.J.L., V.D.M., and D.J.J. are funded by the Australian Government through the Australian Renewable Energy Agency (ARENA) Australian Centre for Advanced Photovoltaics (ACAP). Responsibility for the views, information, or advice expressed herein is not accepted by the Australian Government. This work was performed in part at the Materials Characterisation and Fabrication Platform (MCFP) at the University of Melbourne. This research was undertaken on the SAXS/WAXS beamline at the Australian Synchrotron (part of ANSTO).<SUP>45</SUP> The authors would like to thank the Australian Synchrotron for GIWAXS experiments and Flexible Electronics Lab, CSIRO, Clayton for device fabrication facilities.