Resistive switching based on filaments in metal/PMMA/metal thin film devices

Abstract

The working mechanism of unipolar organic resistive switching thin-film devices is investigated. On the basis of a metal/poly(methyl methacrylate)/metal model system, direct spectroscopic evidence for filament formation is obtained by three-dimensional (3D) imaging with time-of-flight secondary ion mass spectrometry. By means of alternative fabrication methods the claimed influence of metal implantation in the organic layer during fabrication is ruled out. Further, the stability of the resistive switches under oxygen and humidity is investigated leading to a deeper understanding of the processes governing the formation and rupture of filaments.

Memristive Control of Plasmon-Mediated Nonlinear Photoluminescence in Au Nanowires

“…The flow of electrical charges is an unambiguous marker of the formation of conductive channels within the nanogap, , akin to typical memristive devices undergoing resistive changes . Upon electrical stress, various processes are contributing to alter in time the SiO 2 /PMMA environment composing the nanogap, including defect creation produced by electron injection (e.g., oxygen vacancies), Au ions diffusion, clustering, and filamentary growth. − Indeed, PMMA has been successfully employed as a low-cost easily processed organic material promoting filamentary-type resistive switching , whereby electrochemical reactions involving the migration and clustering of metallic ions lead to the formation of an atomic conductive bridge across a gap. , Here, the current trace features a behavior mixing the occurrence of a nonvolatile resistive state shown by the instantaneous rise of the current at the leading edge of the pulses and an evolutionary nature materialized by a slow-growth response of hundreds of ms. The instantaneous rise of I g preceding its growth is most probably linked to tunnel transport through the modified gap.…”

Wave-vector analysis of plasmon-assisted distributed nonlinear photoluminescence along Au nanowires

“…38 Upon electrical stress, various processes are contributing to alter in time the SiO 2 /PMMA environment composing the nanogap, including defect creation produced by electron injection (e.g., oxygen vacancies), Au ions diffusion, clustering and filamentary growth. [39][40][41] Indeed, PMMA has been successfully employed as a low-cost easily-processed organic material promoting filamentary-type resistive switching 42,43 whereby electrochemical reactions involving the migration and clustering metallic ions leads to the formation of an atomic conductive bridge across the gap. 38,44 Here, the current trace features a behavior mixing the occurrence of a non-volatile resistive state shown by the instantaneous rise of the current at the leading edge of the pulses, and an evolutionary nature materialized by a slowgrowth response of hundreds of ms.…”

Investigation of Time–Dependent Resistive Switching Behaviors of Unipolar Nonvolatile Organic Memory Devices

“…Various experimental tools have been employed to investigate the fundamental properties of ORRAM devices; for example, impedance spectroscopy to directly probe the charge trapping in the active layer and a direct spatial mapping of the current paths within the layer via elemental analysis . We have recently employed 1/ f noise measurements to show that the conduction paths in organic nanocomposite memory devices form a percolation network from the resistance scaling of the 1/ f noise .…”