Electrical breakdown of carbon nanotube devices and the predictability of breakdown position

Abstract

We have investigated electrical transport properties of long (>10 μm) multiwalled carbon nanotubes (NTs) by dividing individuals into several segments of identical length. Each segment has different resistance because of the random distribution of defect density in an NT and is corroborated by Raman studies. Higher is the resistance, lower is the current required to break the segments indicating that breakdown occurs at the highly resistive segment/site and not necessarily at the middle. This is consistent with the one-dimensional thermal transport model. We have demonstrated the healing of defects by annealing at moderate temperatures or by current annealing. To strengthen our mechanism, we have carried out electrical breakdown of nitrogen doped NTs (NNTs) with diameter variation from one end to the other. It reveals that the electrical breakdown occurs selectively at the narrower diameter region. Overall, we believe that our results will help to predict the breakdown position of both semiconducting and metallic NTs

Enhanced Field Emission Properties of CNT Film Emitters through Densification using Nitric Acid

“…The generation of defects on the CNTs deteriorates the field emission properties. 32,33 The results support the notion that when densifying the film with a high concentration of nitric acid, the deterioration effect of the CNT film becomes dominant over the densification effect during field emission. We also evaluate field emission characteristics of the emitter using the Seppen−Katamuki (S−K) chart, as depicted in Figure 8c.…”

“…While the film is being densified, the defect density increases on the CNT surface, which becomes substantial at a high concentration of nitric acid exceeding 4 M, as illustrated in Figure . The generation of defects on the CNTs deteriorates the field emission properties. , The results support the notion that when densifying the film with a high concentration of nitric acid, the deterioration effect of the CNT film becomes dominant over the densification effect during field emission.…”

Morphology dependent electrical conduction and breakdown in single TiO2 nanotubes

“… 64 As J – V measurements have been performed in a vacuum atmosphere, the heat dissipation happens mostly through the NT and the electrodes. Also, it has been observed that the extremely resistive part of the NT is broken at a lower current which indicates that breakdown does not always occur at the middle part, 65 and also for shorter NTs, this happens away from the central part of the NT 66 due to the anisotropic temperature profile.…”