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

Significance Blade coating is a promising methodology for the large-scale printing of polymer electronics, affording nonnegligible microstructure control and properties enhancement. Nevertheless, in two-component systems, the optical/electrical/physical properties are largely dominated by phase separation and domain purity phenomena that are challenging to control. Here, we report a mixed-flow microfluidic printing approach to phase purity control, enabled by a printing blade design based on fluid flow simulations. The result is 50% efficiency enhancement for printed all-polymer solar cells vs. conventional printing and similar enhancements for polymer transistors. Mixed flow is a versatile approach to control domain purity in two-component polymeric semiconductor systems and offers a methodology for printing high-performance soft-matter electronics.