Memristors enter a critical developmental stage where emerging large‐scale integration methods face major challenges with severe switching instabilities in the oxide layer. Here, the superior uniformity is achieved within HfO2films by embedding highly ordered metal nanoisland (NI) arrays. Embedded films exhibit a significant reduction in both SET and RESET while displaying enhanced uniformity in operating voltages and resistance states. This behavior is attributed to the concentration of electric fields along Pt and Ti NIs and their interactions with the surrounding oxide film matrix environment, which induce separate and distinct filamentary formation mechanisms that affect the stability. A method is reported to further optimize the uniformity of the SET voltage by translating the NI array position down the film‐thickness dimension towards the bottom electrode. A comparison of the density and distribution of the oxygen vacancies responsible for the formation/dissolution of conducting filaments is made via combined electrostatic force microscopy and conductive atomic force microscopy (c‐AFM) studies. Finally, complete observation of the morphological evolution of conducting filaments produced by Pt and Ti is enabled by 3D c‐AFM nanotomography and cross‐sectional scanning transmission electron microscopy–energy dispersive spectroscopy to provide direct correlations between NI‐oxide interactions and overall switching performance.
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Abstract Layered 2D (PbI2)1−
x (BiI3)x materials exhibit a nonlinear dependence in structural and charge transport properties unanticipated from the combination of PbI2and BiI3. Within (PbI2)1−x (BiI3)x crystals, phase integration yields deceptive structural features, while phase boundary separation leads to new conductance switching behavior observed as large peaks in current during current–voltage (I –V ) measurements (±100 V). Temperature‐ and time‐dependent electrical measurements demonstrate that the behavior is attributed to ionic transport perpendicular to the layers. High‐resolution transmission electron microscopy reveals that the structure of (PbI2)1−x (BiI3)x is a “brick wall” consisting of two phases, Pb‐rich and Bi‐rich. These brick‐like features are 10s nm a side and it is posited that iodide ion transport at the interfaces of these regions is responsible for the conductance switching action.
