Electron transport mechanisms in polymer-carbon sphere composites

TL;DR

This study investigates electron transport in polymer-carbon sphere composites, revealing thermally-induced tunneling as a key mechanism influencing conductivity, with potential implications for designing conductive polymer materials.

Contribution

It introduces a new understanding of electron transport mechanisms, highlighting thermally-induced tunneling in polymer-carbon sphere composites.

Findings

Conductivity peaks at 0.245 S/cm at 258K.

Ohmic I-V characteristics observed across the temperature range.

Thermally-induced tunneling significantly influences electron transport.

Abstract

A set of uniform carbon microspheres (CS) whose diameters have the order of $ 0.125 \mu m$ to $10 \mu m $ was prepared from aqueous sucrose solution by means of hydrothermal carbonization of sugar molecules. A pressed pellet was composed by mixing CSs with polyethylene oxide (PEO). Electrical characterization of the pellet was carried out showing Ohmic current-voltage characteristics and temperature-dependent conductivity in the range $ 80K < T < 300K.$ The conductivity reached a maximum value of $ 0.245 S/cm $ at $ 258K. $ The dependence of conductivity on temperature was theoretically analyzed to determine predominating mechanisms of electron transport. It was shown that thermally-induced electron tunneling between adjacent spheres may take on an important part in the electron transport through the CS/PEO composites.