Oxygen and light sensitive field-effect transistors based on ZnO nanoparticles attached to individual double-wall carbon nanotubes

TL;DR

This study investigates how ZnO nanoparticles attached to double-wall carbon nanotubes affect their electrical and photo-response properties, aiming to enhance applications like solar cells and smart materials.

Contribution

It demonstrates a method for attaching ZnO nanoparticles to nanotubes without long-chain ligands and analyzes the charge transfer and photo-current mechanisms in the resulting FET devices.

Findings

Charge transfer mechanism elucidated via transfer characteristics.

Positive charges on nanoparticles influence gating effects.

Composite shows significant photo-response under various conditions.

Abstract

The attachment of semiconducting nanoparticles to carbon nanotubes is one of the most challenging subjects in nanotechnology. Successful high coverage attachment and control over the charge transfer mechanism and photo-current generation opens a wide field of new applications such as highly effective solar cells and fibre-enhanced polymers. In this work we study the charge transfer in individual double-wall carbon nanotubes highly covered with uniform ZnO nanoparticles. The synthetic colloidal procedure was chosen to avoid long-chained ligands at the nanoparticle-nanotube interface. The resulting composite material was used as conductive channel in a field effect transistor device and the electrical photo-response was analysed under various conditions. By means of the transfer characteristics we could elucidate the mechanism of charge transfer from non-covalently attached semiconducting nanoparticles to carbon nanotubes. The role of positive charges remaining on the nanoparticles is discussed in terms of a gating effect.