Layer-to-island growth of electrodeposited Cu2O films and filamentary switching in single-channeled grain boundaries

Abstract

We investigated a growth behavior of highly oriented and columnar grained cuprous oxide (Cu2O) films, which were obtained through a chelate-assisted electrochemical solution approach. It was demonstrated that the electrochemical growth of Cu2O films followed a layer-to-island growth mode with a critical thickness of ∼190 nm. The chelating agent induced the layer-growth of flat-surfaced films consisting of single-crystalline planar grains, and influenced the preferred orientation of films maintained within the island-growth mode. In particular, the single-crystalline columnar grains with stable interfaces and diameters of 100-200 nm provided highly localized areas of linear grain boundaries for filamentary resistive switching. We measured different conduction behaviors of flat-surfaced films showing nonswitching Ohmic conduction and unipolar memory switching in as-deposited and annealed films, respectively. These different conduction behaviors were found to originate from the microstructure changes generated by the annealing process, which may suggest a clue for the origins of filamentary resistive memory switching in single-channeled grain boundaries. © 2010 American Institute of Physics.