Investigating the Uneven Current Injection in Perovskite-Based Thin Film Bipolar Resistance Switching Devices by Thermal Imaging

Bipolar resistive switching (RS) phenomenon in planar Al/Pr
_0.7
Ca
_0.3
MnO
₃
(PCMO)/Ti devices was investigated by thermoreflectance method. Thermal images of devices undergoing switching were used to quantify the unevenness of injected current under different voltage bias. At low resistance state, the injected current at the current crowding area of the Al/PCMO interface was 1.6 times higher than other regions of the interface. The uneven distribution of injected current indicated the existence of localized resistance at the interface, which cannot be simply measured by electrical measurements. The thermoreflectance method demonstrates the potential applications for in situ current profiling of the RS devices.