Bias-voltage-controlled ac and dc magnetotransport phenomena in hybrid structures

We report some ac and dc magnetotransport phenomena in silicon-based hybrid structures. The giant impedance change under an applied magnetic field has been experimentally found in the metal/insulator/semiconductor (MIS) diode with the Schottky barrier based on the Fe/SiO2/p-Si and Fe/SiO2/n-Si structures. The maximum effect is found to observe at temperatures of 10-30 K in the frequency range 10 Hz-1 MHz. Below 1 kHz the magnetoresistance can be controlled in a wide range by applying a bias to the device. A photoinduced dc magnetoresistance of over 104% has been found in the Fe/SiO2/p-Si back-to-back Schottky diode. The observed magnetic-field-dependent effects are caused by the interface states localized in the insula-tor/semiconductor interface.