Dual-Engineered DPP Polymers: Synergistic Hydrogen Bonding and Ring-Fusion for High-Mobility Organic Field-Effect Transistors.

Abstract

Developing simple and effective molecular design strategies to optimize charge transport mobility remains a key challenge in high-performance organic semiconductors. In this study, we integrate hydrogen bonding (H-B) and ring-fusion (R-F) into a diketopyrrolopyrrole (DPP)-based polymer, yielding a novel material, P-HF. For comparison, a reference polymer (P-B) and a hydrogen-bonded analogue (P-H) were synthesized. The synergistic effects of H-B and R-F dramatically not only enhance both inter- and intramolecular charge transport but also optimize the frontier orbital levels; H-B strengthens intermolecular interactions, enabling localized ordered molecular packing and tighter π-π stacking, while R-F further amplifies these effects meanwhile improving backbone planarity, extending π-conjugation, and optimizing frontier orbital levels. As a result, P-HF achieves an outstanding hole mobility of 5.02 cm2 V-1 s-1, surpassing P-B (0.71 cm2 V-1 s-1) and P-H (2.13 cm2 V-1 s-1), placing it among the highest-performing DPP-based polymers reported. This work demonstrates that combining R-F and H-B offers a viable strategy for designing high-mobility conjugated materials, potentially advancing organic semiconductor development. This dual-engineering strategy is particularly suitable for π-conjugated polymers containing both hydrogen-bonding sites and ring-fused backbones.