Oxygen vacancy induced carrier mobility enhancement in nano-multilayered ZrO₂:Y₂O₃/SrTiO₃ thin films for non-volatile memory devices

The influence of oxygen vacancy-dominated carrier mobility on the performance of memristors has attracted considerable attention. The device’s carrier mobility can be significantly improved by forming a nano-multilayered heterostructure when the individual layer thickness is below a critical value. In this work, Pt/[ZrO₂: Y₂O₃ (YSZ)/SrTiO₃ (STO)]_n/Nb:SrTiO₃ (NSTO) memristive devices were configurated through laser pulse deposited YSZ/STO nano-multilayered active layer with both Pt and NSTO acting as top and counter electrodes. Specifically, the Pt/[YSZ/STO]₅/NSTO device with five consecutive layers of YSZ/STO thin film shows superior memristor performance, and its corresponding carrier mobility presents a significantly enhanced value compared to that of other periodic numbers of YSZ/STO composed memristive devices. This can be attributed to the increase of oxygen vacancy concentration in the device, as evidenced by both experimental results and theoretical analysis. This work provides a significant approach in improving the performance of memristor dominated by oxygen vacancy transporting mechanism.