Environmentally benign fabrication processes for high-performance polymeric semiconductors

Like other polymer industries, the polymeric semiconductor industry is under pressure due to the need for eco-friendly processes and regulations on the emission of harmful solvents. However, in the case of polymeric semiconductors, the use of halogenated solvents (or at least aromatic solvents) has been considered essential because the self-assembly properties of the alkyl chain determine the performance of the final device; however, these solvents are harmful to the environment. In this review, the research efforts to avoid using toxic organic solvents without sacrificing high semiconductor performances are summarized for: (1) non-halogenated solvents, (2) polar solvents, and (3) aqueous media. More specifically, methodologies to achieve stable dissolution or dispersion of polymeric semiconductors in greener solvents are introduced: polymerization with new backbone structures, polymerization with new side chain structures, and various mini-emulsion-based nanoparticle production methods. This review aims to contribute to the development of new technologies that enable eco-friendly/high-performance processes in the field of organic semiconductors by providing up-to-date information on the eco-friendly processes of organic semiconductors.