Mixed-flow design for microfluidic printing of two-component polymer semiconductor systems

Gang Wang, Liang Wen Feng, Wei Huang, Subhrangsu Mukherjee, Yao Chen, Dengke Shen, Binghao Wang, Joseph Strzalka, Ding Zheng, Ferdinand S. Melkonyan, Jinhui Yan, J. Fraser Stoddart, Simone Fabiano, Dean M. DeLongchamp, Meifang Zhu, Antonio Facchetti, Tobin J. Marks

Research output: Contribution to journalArticlepeer-review


The rational creation of two-component conjugated polymer systems with high levels of phase purity in each component is challenging but crucial for realizing printed soft-matter electronics. Here, we report a mixed-flow microfluidic printing (MFMP) approach for two-component π-polymer systems that significantly elevates phase purity in bulk-heterojunction solar cells and thin-film transistors. MFMP integrates laminar and extensional flows using a specially microstructured shear blade, designed with fluid flow simulation tools to tune the flow patterns and induce shear, stretch, and pushout effects. This optimizes polymer conformation and semiconducting blend order as assessed by atomic force microscopy (AFM), transmission electron microscopy (TEM), grazing incidence wide-angle X-ray scattering (GIWAXS), resonant soft X-ray scattering (R-SoXS), photovoltaic response, and field effect mobility. For printed all-polymer (poly[(5,6-difluoro-2-octyl-2H-benzotriazole-4,7-diyl)-2,5-thiophenediyl[4,8-bis[5-(2-hexyldecyl)-2-thienyl]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl]-2,5-thiophenediyl]) [J51]:(poly{[N,N′-bis(2-octyldodecyl) naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)}) [N2200]) solar cells, this approach enhances short-circuit currents and fill factors, with power conversion efficiency increasing from 5.20% for conventional blade coating to 7.80% for MFMP. Moreover, the performance of mixed polymer ambipolar [poly(3hexylthiophene-2,5-diyl) (P3HT):N2200] and semiconducting:insulating polymer unipolar (N2200:polystyrene) transistors is similarly enhanced, underscoring versatility for two-component π-polymer systems. Mixed-flow designs offer modalities for achieving high-performance organic optoelectronics via innovative printing methodologies.

Original languageEnglish (US)
Pages (from-to)17551-17557
Number of pages7
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number30
StatePublished - Jul 28 2020


  • Mixed-flow design
  • Phase purity
  • Printed electronics
  • Semiconducting polymer
  • Two component

ASJC Scopus subject areas

  • General


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