Reversible switching characteristics of polyfluorene-derivative single layer film for nonvolatile memory devices

This letter reports on reversible switching behavior of metal-insulator-metal type nonvolatile organic memory devices using polyfluorene-derivative (WPF-oxy-F) single layer film. The current-voltage (I-V) characteristics showed that the WPF-oxy-F single layer film has two distinguished resistance states, low resistance state and high resistance state, with four orders of on/off ratio (Ion Ioff ∼ 104). From the analysis of I-V curves, area dependent I-V characteristics, and current images obtained by conducting atomic force microscopy we propose that the space charge limited current with filamentary conduction is a potential mechanism for the reversible switching behavior of WPF-Oxy-F memory devices.