Ground-State Electron Transfer in All-Polymer Donor: Acceptor Blends enables The Aqueous Processing of Water-Insoluble Conjugated Polymers

Conjugated polymers offer a unique blend of solution processability, mechanical flexibility, and semiconducting properties, making them invaluable for diverse applications in industries ranging from displays and energy storage to healthcare. However, conventional processing methods often involve hazardous solvents, posing challenges for broad commercial and sustainable adoption. To address this, we introduce a novel approach based on mutual electrical doping in donor:acceptor polymer blends, which facilitates the dispersion of water-insoluble conjugated polymers in aqueous solutions. This approach leads to macromolecular charge-transfer salts with 10,000× higher electrical conductivities than the pristine polymers, low work function, and excellent thermal/solvent stability, providing a versatile platform for various electronic devices. The resulting conductive, water-processable inks demonstrate exceptional performance in non-fullerene organic solar cells, organic electrochemical transistors, inverters, and artificial neurons. This breakthrough offers a practical solution for achieving large-scale and sustainable implementation of organic electronics without the need for traditional chemical modifications.