Contribution of the Multiple Charge-Transfer Chromophore to the Orientation Stability of the Poled Polymer Film

One of the novel multidimensional charge-transfer (CT) chromophores, 2-[4-(4,5-di(4-nitrophenyl)imidazolyl)phenyl]-4,5-di(4-aminophenyl)imidazole (DNPIPDAPI), was designed and synthesized; the polyimide was formed with it and 2,5-bis(4-aminophenyl)-3,4-diphenylthiophene (TPTDA) (BMI). The thermal and temporal stability of the poling-induced orientation were evaluated. The temporal orientation of the poled polyimide film with DNPIPDAPI was over 1000 h at 150 °C, retaining 85% of the initial d 33 value. Comparing with 1-D chromophores, the synthetic multiple CT chromophore possesses a better property in controlling the decay of the SHG activity.