Study of chromophore orientation dynamics in photorefractive polymer PVK:5CB:C₆₀

Based on the gas-model, a non-gas-model for the reorientation of chromophores in photorefractive polymers was established by considering the effect of polymer on the reorientation of chromophores and the effect of applied electric field on the chromophores. A numerical method was used to solve the model equation. The influences of the applied electric field and temperature on the dynamic and steady-state reorientation of chromophores were discussed according to the computation results. Also, the results given by non-gas-model are compared with those by gas-model. Using the transient ellipsometry techniques, we studied the dynamic orientation behaviour of chromophores 4,4′-n-pentylcyanobiphenyl (5CB) in the photorefractive composite consisting of the polymer (N-vinylcarbazole) (PVK) doped with 5CB and C₆₀. The dependencies of the orientation parameters on the applied electric field and temperature are measured. Comparisons between the theoretical and the experimental results showed that the non-gas-model is reasonable.