Fig. 8
Reproduced with permission from Ref. [63]. Copyright 2018, Springer Nature
Self-rectifying memristors. a A schematic illustration of the NP TaOx memristor and its cross-sectional TEM image. The white dotted circles indicate nanopores within the NP TaOx layer. b–d XPS analysis results of the fabricated device as functions of the depth and the applied voltage. e A top-view SEM image of the crossbar array consisting of the NP TaOx memristors. f I-V curves of four memristors in the 2 × 2 sub-array. g, h Histogram plots of the reading current values of the selected (blue) and unselected memristors (red) when the unselected memristors are in the OFF (g) and ON states (h).