Temporal analysis of both the photorefractive mechanism and soliton propagation in a slab semiconductor waveguide is presented. As an example, a structure based on GaAs/AlGaAs MQWs was investigated. Both a numerical and simple analytical approach based on the bipolar band-transport model is used to derive a temporal photorefractive response on localized illumination. The corresponding propagation problem describing the evolution of screening soliton profiles in media with quadratic electro-optic effect was also discussed.