Ultrafast dynamics of interfacial electric fields in semiconductor multilayers was measured using pump-probe second-harmonic generation (SHG). A pump beam was tuned to excite carriers in all the layers of heterostructures. The carrier dynamics manifested itself via electric fields created by charge separation due to carrier redistribution at the interfaces. A strong enhancement of the induced electric field caused by hybridization of the conduction and valence bands at the interface was found.
