Tuning domain size and crystallinity in isoindigo/PCBM organic solar cells via solution shearing [electronic resource].
- Washington, D.C. : United States. Dept. of Energy. Office of Energy Efficiency and Renewable Energy, 2016.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- pages 79-87 : digital, PDF file
- Additional Creators:
- SLAC National Accelerator Laboratory
United States. Department of Energy. Office of Energy Efficiency and Renewable Energy
United States. Department of Energy. Office of Scientific and Technical Information
- Despite having achieved the long sought-after performance of 10% power conversion efficiency, high performance organic photovoltaics (OPVs) are still mostly constrained to lab scale devices fabricated by spin coating. Efforts to produce printed OPVs lag considerably behind, and the sensitivity to different fabrication methods highlights the need to develop a comprehensive understanding of the processing-morphology relationship in printing methods. Here we present a systematic experimental investigation of a model low bandgap polymer/fullerene system, poly-isoindigo thienothiophene/PC<sub>61</sub>BM, using a lab-scale analogue to roll-to-roll coating as the fabrication tool in order to understand the impact of processing parameters on morphological evolution. We report that domain size and polymer crystallinity can be tuned by a factor of two by controlling the temperature and coating speed. Lower fabrication temperature simultaneously decreased the phase separation domain size and increased the relative degree of crystallinity in those domains, leading to improved photocurrent. We conclude that domain size in isoindigo/PCBM is dictated by spontaneous phase separation rather than crystal nucleation and growth. Moreover we present a model to describe the temperature dependence of domain size formation in our system, which demonstrates that morphology is not necessarily strictly dependent on the evaporation rate, but rather on the interplay between evaporation and diffusion during the printing process.
- Published through SciTech Connect.
Organic Electronics 40 C ISSN 1566-1199 AM
Kevin L. Gu; Yan Zhou; Xiaodan Gu; Hongping Yan; Ying Diao; Tadanori Kurosawa; Baskar Ganapathysubramanian; Michael F. Toney; Zhenan Bao.
- Funding Information:
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