Resistive Switching of Vertically Aligned Carbon Nanotubes for Advanced Nanoelectronic Devices

Scanning Probe Techniques for Characterization of Vertically Aligned Carbon Nanotubes

“…The height of the VA CNT is not displayed correctly on the STM image due to the peculiarities of measuring the VA CNT array by the STM [36]. Based on the CVC of the individual VA CNT (Figure 8b), it can be concluded that the individual VA CNT exhibits two conduction states: high resistance when the voltage is varied from 0 to 10 V and low resistance when the voltage varies from 10 to 0 V, which is due to the manifestation of a memristor effect in VA CNT [3,26,29,39,40]. The low-resistance state of the VA CNT was used to determine the resistance of the nanotube, since there is no additional resistance in VA CNT associated with the internal electric field in the nanotube [3,40].…”

“…The main shortcoming of this method was the use of bending stiffness as a rigidity parameter of theoretical and experimental dependencies, from which the value of the Young's modulus of the VA CNT is calculated [11] This fact significantly reduced the reliability of the obtained results. To eliminate this shortcoming, we proposed a technique for determining the bending stiffness (EI) eff for each i-tube interacting with the indenter using experimental dependences [22,28,29]. For this the force P acting on one CNT was represented as [22]:…”

“…Further, a modeling of the VA CNT deformation under the action of an external electric field was carried out to determine the quantitative values of the adhesion of VA CNTs to the substrate [3,29,40]. The results of the modeling showed that the VA CNT deformation increases with increasing voltage from 10 V to 30 V. So the elongation at the VA CNT base (x = 0.01 L) ΔL 0 is 0.037, 0.0391, 0.0404, 0.0419, 0.0441 and 0.0445 nm for a VA CNT with D = 70, 80, 90, 100, 110 and 120 nm, respectively, at corresponding voltage at the detachment (Figure 10).…”

“…This chapter describes unique techniques for determining the height, Young's modulus, bending stiffness, resistivity and adhesion to a substrate of vertically aligned carbon nanotubes, based on the methods of scanning probe microscopy. Described techniques can be used for nanodiagnostics of parameters of individual vertically aligned carbon nanotubes and for creation of nanoelectronic elements and devices on their basis [1,11,21,23,[25][26][27][28][29].…”

“…Schematics of the nanoindentation process of the VA CNT array: (a) the deflection of the first nanotube and the touching of the second nanotube of the indenter with increasing applied force; (b) the interaction of the indenter with i nanotubes at depth h[29].…”