Conjugated Polyions Enable Organic Photovoltaics Processed from Green Solvents YeGang DoumonNutifafa Y. RoussevaSylvia LiuYuru Abdu-AguyeMustapha LoiMaria A. HummelenJan C. Jan Anton KosterL. ChiechiRyan C. 2019 This paper describes the design, synthesis, and optical and electronic properties of two conjugated polymers <b>CPIZ-B</b> and <b>CPIZ-T</b> that incorporate closed-shell cations into their conjugated backbones, balanced by anionic pendant groups. The zwitterionic nature of the polymers renders them soluble in and processable from polar, protic solvents to form semiconducting films that are not doped. These unique properties are confirmed by absorption and electron paramagnetic resonance spectroscopy. The energies of the unoccupied states respond to the tritylium moieties in the conjugated backbone, while the occupied states respond to the electron-donating ability of the uncharged, aromatic units in the backbone. Films cast from 80:20 HCOOH/H<sub>2</sub>O by volume show good electron mobilities, enabling a photovoltaic effect in proof-of-concept, bilayer solar cells.