Design Strategies to Enable Sustainability in Polymeric Organic Semiconductors

As organic semiconductors move closer to widespread application, it is increasingly important to reduce their end-of-life environmental impact and limit future electronic waste. Developing design strategies that enable degradable or recyclable conjugated polymers is therefore essential. This work first explored a series of ester-incorporated monomers that allow depolymerization under mild conditions, enabling high monomer recovery and closed-loop recycling back to the parent polymer. However, incorporating ester linkers disrupt backbone conjugation, creating a fundamental trade-off between recyclability and electronic performance. To address this challenge, two complementary strategies (physical blending and chemical blending) are implemented to balance sustainability and charge transport. Physical blending introduces small amounts of a fully conjugated polymer to restore mobility while maintaining high recyclable or degradable content, whereas chemical blending (terpolymerization) provides a modular route to enhance performance while preserving backbone cleavability. Although both approaches improve device performance, the resulting materials still underperform relative to fully conjugated, non-degradable semiconductors. To overcome this limitation, the final part of this work shifts away from designing new degradable linkers and instead leverages reactive groups present in high-performing polymers. Vinylene functionality is present in a record-breaking organic semiconductor used in organic field-effect transistors and high-efficiency organic photovoltaics. Motivated by this, a ruthenium-catalyzed metathesis strategy has been developed for vinylene-containing polymeric organic semiconductors to achieve closed-loop recycling without sacrificing conjugation. Overall, this dissertation advances sustainable design principles for recyclable polymeric organic semiconductors.