Contribution of impurity ions to spatial-temporal distribution of local electric field in nematic liquid crystal cell

The influence of impurity ions on the spatiotemporal distribution of the local electric field in a planar nematic liquid crystal (NLC) cell with blocking electrodes has been investigated. Numerical simulation of the switching dynamics of the NLC director has been performed using the Poisson–Nernst–Planck and nonlinear Ericksen–Leslie equations at the driving electrical voltage exceeding the Fredericksz threshold. The authors take into account the influence of the effective permittivity associated with the reorientation of the NLC director on the dynamics of electrodiffusion of impurity ions. Spectral analysis of the local electric field reveals the presence of higher harmonics caused by the spatial inhomogeneity of ionic impurity distribution. It has been proven that the presence of these harmonics in the spectral composition of the local electric field leads to a nonlinearity of the NLC director switching dynamics.