The sustainability of organic semiconductors has emerged as a critical challenge for reducing electronic waste, motivating the development of recyclable and degradable conjugated polymers. Incorporating ester linkages into polymer backbones enables depolymerization and repolymerization; however, these nonconjugated units disrupt the pi-conjugation and result in severe degradation of charge transport. Here, we address this fundamental trade-off between sustainability and device performance in diketopyrrolopyrrole (DPP)-based organic semiconductors by implementing two complementary strategies: physical blending and chemical blending of fully conjugated and ester-incorporated polymers. In the physical blending strategy, the introduction of only 10 wt% of a fully conjugated polymer, P(DPP-2T), into TEET- or TET-containing DPP polymers, in which the backbone esters are introduced as cleavable linkages, leads to dramatic enhancements in hole mobility – up to 330-fold and 380-fold, respectively – when compared to the corresponding neat polymer, while retaining 90 wt% of the ester-containing polymer in the film. By contrast, chemical blending via terpolymerization yields more limited mobility enhancement, as ester segments distributed along the backbone constrain intrachain charge transport, requiring substantially higher DPP-2T content to achieve appreciable electrical performance. Overall, these results demonstrate that physical blending can more efficiently restore charge transport in the ester-incorporated polymers at lower content of the corresponding fully conjugated polymer, while chemical blending requires higher content of conjugated segments to achieve comparable device performance. This work establishes a general framework for designing sustainable organic semiconductors that minimize electronic waste without sacrificing field-effect transistor performance.

Fluorination of the donor polymer or non-fullerene acceptor (NFA) in an organic photovoltaic device is an effective method to improve device efficiency. Although there have been many studies on donor polymer fluorination, blends containing both a fluorinated donor and fluorinated NFA have rarely been reported. In this study, we use two donor polymers (4′-FT-HTAZ and 4′-FT-FTAZ) and two NFAs (ITIC-Th and ITIC-Th1) with different amounts of fluorine (from 2F to 6F) to investigate how the degree of fluorination in a blend impacts device performance. We find that fluorinating the NFA leads to a higher short-circuit current density (J_sc) and fill factor (FF), however, the open-circuit voltage (V_oc) is decreased due to a depressed lowest unoccupied molecular orbital (LUMO) level. Adding additional fluorine to the donor polymer does not have a large effect on the J_sc or FF, but it does lead to an improved V_oc. By fluorinating the NFA and having more fluorine on the donor polymer, we obtain both a high J_sc and V_oc simultaneously, leading to a power conversion efficiency over 10% in the case of 4′-FT-FTAZ: ITIC-Th1, which has the most amount of fluorine (6F).