Low-Temperature Solution-Based Molybdenum Oxide Memristors.

Solution-based memristors have gained significant attention in recent years due to their potential for the low-cost, scalable, and environmentally friendly fabrication of resistive switching devices. This study is focused on the fabrication and characterization of solution-based molybdenum trioxide (MoO3) memristors under different annealing temperatures (200 to 400 °C). A MoO3 ink recipe is developed using water as the main solvent, enabling a simplified and cost-effective fabrication process. Material analysis reveals the presence of a Mo6+ oxidation state and an amorphous structure in the films annealed up to 250 °C. Electrical tests confirm a bipolar resistive switching behavior in the memristors according to the valence change mechanism (VCM). Endurance tests demonstrate stable memristors, indicating their robust nature after multiple cycles. Memristors annealed at 250 °C exhibit a nonvolatile behavior with a retention time up to 105 s under ambient air conditions. The high reproducibility observed in these memristors highlights their potential for practical applications and scalability.

Emergent solution based IGZO memristor towards neuromorphic applications.

Solution-based memristors are emergent devices, due to their potential in electrical performance for neuromorphic computing combined with simple and cheap fabrication processes. However, to achieve practical application in crossbar design tens to hundreds of uniform memristors are required. Regarding this, the production step optimization should be considered as the main objective to achieve high performance devices. In this work, solution-based indium gallium zinc oxide (IGZO) memristor devices are produced using a combustion synthesis process. The performance of the device is optimized by using different annealing temperatures and active layer thicknesses to reach a higher reproducibility and stability. All IGZO memristors show a low operating voltage, good endurance, and retention up to 105 s under air conditions. The optimized devices can be programmed in a multi-level cell operation mode, with 8 different resistive states. Also, preliminary results reveal synaptic behavior by replicating the plasticity of a synaptic junction through potentiation and depression; this is a significant step towards low-cost processes and large-scale compatibility of neuromorphic computing systems.