Diffusion mediated photoconduction in multi-walled carbon nanotube films

TL;DR

This study explores how near-infrared light induces photoconduction in multi-walled carbon nanotube films, revealing dependence on laser position, electrode separation, and underlying mechanisms involving Schottky barriers and charge diffusion.

Contribution

It provides new insights into the photoconduction mechanism in MWNT films, highlighting the roles of Schottky barrier modulation and charge carrier diffusion.

Findings

Photocurrent strongly depends on laser spot position.

Time constant of photoresponse increases with electrode separation.

Photoconduction is explained by Schottky barrier modulation and charge diffusion.

Abstract

We investigated the mechanism for photoconduction in multi-walled carbon nanotube (MWNT) film of various electrode separations upon near infrared illumination. In addition to observing strong dependence of photocurrent on the position of the laser spot, we found that the time constant of the dynamic photoresponse is slow and increases with increasing electrode separations. The photoconduction mechanism can be explained by the Schottky barrier modulation at the metal-nanotube film interface and charge carrier diffusion through percolating MWNT networks.