Chiral Assemblies of Conjugated Polymers for Controlling Charge and Spin Transport

Intimately connected to the rule of life, chirality remains a long-time fascination in biology, chemistry, physics and materials science. Chiral structures, e.g., nucleic acid and cholesteric phase developed from chiral molecules are common in nature and synthetic soft materials. Chiral semiconductors have been long leveraged by Nature to efficiently transduce energy and transfer electrons. However, it has been rarely used in synthetic semiconductors due to synthetic challenges. We recently discovered chiral emergence from high performance achiral conjugated polymers, in which hierarchical helical structures spanning nano- to micron scales emerge from a multistep assembly pathway in an evaporating meniscus during coating and printing. We further show that such hierarchical helical structures can be largely modulated by non-equilibrium processing during solution printing as well as by subtle changes in the polymer structure. With the ability to widely tune helical structures, we set out to demonstrate the ability of chiral helical structures in enhancing chemical doping efficiency and conductivity in redox polymers, and in efficiently converting spin to charge promising for spintronic applications.