High‐performance electro‐optic materials featuring enhanced thermal stability through dual‐donor structural crosslinking engineering

Abstract Organic electro‐optic (EO) materials combining high EO efficiency with robust thermal stability are essential for next‐generation optoelectronic transceivers. However, limited chromophore loading and poor thermal stability during poling processing and practical application have restricted their EO performance. Here, a dual‐donor crosslinking strategy is proposed through the synthesis of highly efficient binary crosslinkable dual‐donor chromophores (YZ1–YZ6) based on anthracene–acrylate, anthracene–maleimide and maleimide–furan Diels–Alder reactions, as well as azide–alkyne Huisgen cycloaddition. Following electric‐field poling, polymeric crosslinked networks are formed at designated temperatures, effectively locking molecular orientation and markedly enhancing thermal stability. The resulting crosslinked films exhibit large EO coefficients of 257–301 pm/V and elevated glass transition temperatures ( T g ) of 107–187°C, together with high chromophore densities of 3.73–4.26 × 10 20 molecules cm −3 . Long‐term thermal aging at 85°C demonstrates excellent stability, with 2:1 YZ1:YZ2 and 2:1 YZ5:YZ6 retaining 99.68% and 95.01% of their initial r 33 values after 500 h, respectively. This work provides an effective molecular‐engineering strategy for the systematic development of high‐performance organic EO materials.