Highly Efficient and Stable Binary Cross‐Linkable/ Self‐Assembled Organic Nonlinear Optical Molecular Glasses

Abstract

Abstract The development of electro‐optical materials with high chromophore loading levels that possess ultrahigh electro‐optic coefficients and high long term alignment stability is a challenging topic. Anthracene‐maleimide Diels–Alder (DA) reaction and π–π interaction of Anthracene‐pentafluorobenzene and benzene‐pentafluorobenzene are developed for making highly efficient binary cross‐linkable/self‐assembled dendritic chromophores FZL1‐FZL4. A covalently or non‐covalently cross‐linked network is formed by DA reaction or π–π interaction after electric field poling orientation, which greatly improves the long‐term alignment stability of the materials. An electro‐optic coefficient up to 266 pm V−1 and glass transition temperature as high as 178 °C are achieved in cross‐linked film FZL1/FZL2, and 272–308 pm V−1 is achieved for self‐assembled films FZL1/FZL4 and FZL3/FZL4 due to high chromophore density (3.09–4.02 × 1020 molecules cm−3). Long‐term alignment stability tests show that after heating at 85 °C for over 500 h, 99.73% of the initial r33 value is maintained for poled crosslinked electro‐optic films 1:1 FZL1/FZL2. The poled self‐assembled electro‐optic films 1:1 FZL1/FZL4 and 1:1 FZL3/FZL4 can still maintain more than 97.11% and 98.23%, respectively, of the original electro‐optic coefficient after being placed at room temperature for 500 h. The excellent electro‐optic coefficient and stability of the material indicate the practical application prospects of organic electro‐optic materials.

Keywords

• alignment stability
• chromophores
• cross‐linking
• nonlinear optics
• self‐assembly