Breaking Trade‑Offs in Electro‑Optical Materials: Dendritic Crosslinkable Multichromophore for Ultrahigh Electro‐Optic Activity and Thermal Stability

ABSTRACT We report the first design and synthesis of multichromophore‐containing dendritic cross‐linked materials (DLD1–DLD3) that combine an ultrahigh electro‐optic coefficient, high poling efficiency, and a high glass transition temperature. Anthracene and acrylate groups were introduced into three‐branched multichromophores DLD1 and DLD3 and two‐branched multichromophore DLD2, respectively. The configuration of the multichromophore can effectively minimize unwanted attenuation of nonlinear optical materials at high chromophore loading, thereby enhancing the polarization efficiency of the cross‐linked system. The average poling efficiency (r 33 /Ep) of the cross‐linked 2:1 DLD1:DLD3) was as high as 2.80 ± 0.10 nm 2 /V 2 , which was much higher than a common binary cross‐linking system with the same donor. These materials exhibit excellent performance, including a glass transition temperature (T g ) up to 182°C and an electro‐optical coefficient (r 33 ) of 287–301 pm/V. This performance is attributed not only to the chromophore concentration (5.30–5.31 × 10 2 0 molecules•cm − 3 ) but also to the hyperbranched structure of the materials. Long‐term thermal stability experiments fully demonstrate that the cross‐linked and poled electro‐optical films DLD1‐DLD3 can retain over 99% of their initial r 33 values after being stored at 85°C for more than 500 h. The outstanding performance of DLD1‐DLD3 provides a potential solution for their application in high‐performance electro‐optical modulators and other Advanced optoelectronic devices.