Enhanced anti-Ohmic effect in NiFe/KTaO₃ Schottky junction

The anti-Ohmic effect in a Schottky junction is an interesting phenomenon in the process of non-equilibrium carriers' diffusion. When this phenomenon occurs, the voltage decreases with the increase in the resistivity under a constant diffusion current. Compared with the p-Si/NiFe Schottky junction, KTaO₃ with a wider bandgap is used as the substrate in this work, and the anti-Ohmic effect is significantly enhanced. Through in-depth investigation, we have ruled out the influence of substrate resistivity and finally attributed the enhancement of the anti-Ohmic effect to a decreased ideality factor in the KTaO₃/NiFe junction. By analyzing the relationship between anisotropic lateral photovoltage (ALPV) and anisotropic magnetoresistance, it is found that the theoretical dependence of ALPV on temperature is consistent with the experimental results. This research provides an idea and a theoretical basis for further optimizing the performance of electronic devices based on Schottky junctions.