We discuss peculiarities of nonlinear and electrooptical processes caused by the influence of an external electric field acting along the interface between a semiconductor substrate and a liquid crystal (LC). It is shown that the specific interaction between surface atoms of semiconductor and interfacial molecules of LC leads to significant changes in the anchoring conditions of LC molecules on the semiconductor substrate. Significant enhancement of the strength of optical nonlinearity in homeotropically oriented LC cells is experimentally observed. The characteristic time of conventional reorientation induced by AC-field in planar LC-cell is decreased by up to one order of magnitude due to the presence of external longitudinal electric field. The results of observations can be attributed to reorientation of the interfacial layer of LC molecules due to the influence of the tangential electric field. These phenomena provide opportunities for increase of the operation speed of LC photonics components. Enhanced optical nonlinearity of LC can widen the dynamic range of laser beam and optics characterization devices that are based on orientational optical processes.