Hybrid organic–inorganic materials containing poled zwitterionic push–pull chromophores

Dihydroxy functionalised zwitterionic push-pull chromophores have been introduced in 3-glycidoxypropyltrimethoxysilane, tetraethylorthosilicate and N-[(3-trimethoxysilyl)propyl]ethylenediamine derived hybrid materials. Hybrid films have been deposited as thick layers via spin-coating. The amine groups introduced with the organically modified alkoxide bearing amine functionalities have been found to have an effective scavenger effect of the dye photobleaching.The addition, during the synthesis of the precursor sol, of N-hydroxyl carbazole has allowed to reach up to 20% of chromophore concentration avoiding the formation of aggregates within the matrix. The NLO properties of the material, after poling, have shown a good temporal stability, with retention of ca. 70% of the initial signal value, after several months, providing a d33 value of ∼50÷70 pm V−1 at the wavelength of 1.064 μm.