Studies of relaxation processes in poled dipolar dye-doped polymeric films

Betaine-type dipolar molecules have received considerable attention because of their large dipole moments and optical nonlinearities. Two betaines containing the indan-1,3-dione anion part and N-pyridinium cation part have been studied. The host-guest systems that have obvious advantages of synthetic simplicity are chosen. The high intensity electric field corona poling was used to generate dipole orientation of betaine molecules in polymer matrices. Results obtained from surface potential studies of poled thin films at heating and irradiation in photoinduced charge transfer spectral region are presented. The surface potential disappears completely after the host-guest system is heated above its glass transition temperature. Reversible switching of the surface potential is observed on irradiation in photoinduced charge transfer spectral region.