Nanoscale Mapping of Carrier Mobilities in the Ballistic Transports of Carbon Nanotube Networks

Abstract

Much progress has been made in the nanoscale analysis of nanostructures, while the mapping of key charge transport properties such as a carrier mobility remains a challenge, especially for one-dimensional systems. Here, we report the nanoscale mapping of carrier mobilities in carbon nanotube (CNT) networks and show that charge transport behaviors varied depending on network structures. In this work, the spatial distribution of localized charge transport properties such as mobilities and charge trap densities in CNT networks were mapped via a scanning noise microscopy. The mobility map was obtained from the conductivity maps measured at different back-gate biases, showing up to two orders of mobility variations depending on localized network structures. Furthermore, from the maps, correlations between mobility/ conductivity and charge trap density were analyzed to determine charge transport mechanisms. In metallic CNT networks, the regions with rather high (low) or low (high) charge trap densities (mobilities) exhibited a dif fusive or ballistic transport behavior, respectively. Interestingly, semiconducting CNT networks also exhibited a gradual transition from a diffusive to a ballistic transport behavior as the CNT mobility was increased by reaching the on-state with negative gate biases. The mapping of the cross-patterned CNT network showed that metallic CNT electrodes could achieve a good electrical contact with semiconducting CNTs without high contact resistance regions. Since this method allowed one to map versatile charge transport properties such as mobility, conductivity, and charge trap density, it can be a powerful tool for basic research about charge transport phenomena and practical device applications.

Charge Dispersion Strategy for High‐Performance and Rain‐Proof Triboelectric Nanogenerator

“…These results usually suggest a tunneling mechanism for charge transfer, which has been widely reported in the literatures. [ 47–50 ]…”

“…These results usually suggest a tunneling mechanism for charge transfer, which has been widely reported in the literatures. [47][48][49][50] Like traditional TENGs, the output performance of our CN-TENG was also related to applied force, operating frequency, and surface roughness. [51][52][53][54][55] The varying patterns were similar to those for traditional TENGs.…”

Charge Transport Advancement in Anti‐Ambipolar Transistors: Spatially Separating Layer Sandwiched between N‐Type Metal Oxides and P‐Type Small Molecules

“…All these factors are clearly reflected and observed within the LFN analysis. [38,39] Although prior studies have endeavored to decipher the operational principles of AATs using various methods, [40,41] their scope has been restricted by methodological constraints. For example, they confined their investigation to electron flow using operando photoemission electron microscopy, R. Hayakawa et al omitted to evaluate hole conduction, consequently necessitating certain implicit assumptions in analyzing the working principle of the AAT.…”

A Comprehensive Overview on Biochar-Based Materials for Catalytic Applications

“…Contrary to thermal catalytic processes, electrocatalytic ones are deeply affected by the quality of the carbon utilized. BC treated at temperatures higher than 800 • C has shown very interesting electric properties [30,191], but they are still far away from those of carbon nanotubes [192] and graphene-related materials [193]. Nevertheless, the electron mobility of thermally annealed BC is quite high [194,195], and the production of selfstanding electrodes [196] spread the use of BCSCs in several applications discussed in the next sections.…”