Electric field-dependent bipolar resistive switching in electrochemically anodized MoO₃

In this article, we presented the electrical response of electrochemically prepared anodic orthorhombic phase molybdenum trioxide (α-MoO₃) as an oxide-based resistive switching material. Post-annealed samples were confirmed with presence of crystalline α-MoO₃ by XRD and Raman spectroscopy, along with uniform microstructured granular morphology was observed by FESEM imaging. High-resolution XPS analysis confirms the presence of oxygen vacancy defects, which play a crucial role in governing the resistive switching mechanism. The electrical current–voltage (IV) measurements were performed using a metal–insulator–metal (MIM) architecture. In this configuration, molybdenum (Mo) foil served as the bottom layer, self-assembled anodic molybdenum oxide (α-MoO₃) functioned as the active switching layer, and metallic silver (Ag) comprised the top electrode. Ag/α-MoO₃/Mo devices exhibited reproducible bipolar resistive switching (BRS). At low bias (± 0.5 V), the devices displayed nonzero crossing hysteresis attributed to interfacial capacitive and ionic polarization effects, while at higher bias (± 1.5 V) induced conventional filamentary BRS with a SET voltage of + 0.4 V and RESET voltage of –0.6 V. A clear voltage threshold (± 1.1 V) marked the transition between abnormal and normal switching modes. We assessed the endurance of the switching device over 30 cycles and its retention capabilities for up to 10^3 s. These results demonstrate that the anodized α-MoO₃ can be a cost-effective and scalable switching material, with field-dependent switching suitable for applications in multi-level memory, neuromorphic computing, and hardware security.