Improved resistive switching behavior of multiwalled carbon nanotube/TiO2 nanorods composite film by increased oxygen vacancy reservoir

Abstract

The non-linear nature in the current-voltage relationship and good resistive switching characteristics were demonstrated with the help of TiO2 nanorods-functionalized multiwalled carbon nanotube (fMWCNT) composite grown by the low-cost hydrothermal method. The composites were characterized by X-ray diffraction, scanning electron microscopy, Raman, photoluminescence, and X-ray photoelectron spectroscopy to investigate the structural, morphological, and chemical composition of composite films. The resistive switching characteristics of the TiO2-fMWCNT nanocomposites were found to be strongly dependent on the fMWCNT concentration. The enhanced switching performance is associated with the surface nanostructure and chemical composition of the nanocomposites. Owing to the hierarchical rutile TiO2 nanorods and opportune fMWCNT content, the nano-composite based device with 0.03 wt % fMWCNT exhibited the best resistive switching performance with good endurance and retention non-volatile memory properties. Interestingly, with the optimized stoichiometric composition and operation conditions, forming-free, low operational voltage, self-rectifying like properties have been simultaneously achieved, which are some of the prerequisites for next-generation memory devices. In addition to this, the double-valued charge-magnetic flux nature of the developed devices was demonstrated. The experimental current-voltage characteristics are well-matched with the Ohmic and Schottky conduction mechanisms.