Suitability of carbon nanotubes grown by chemical vapor deposition for electrical devices

TL;DR

This study evaluates the use of chemical vapor deposition-grown carbon nanotubes for electrical device applications, focusing on device preparation, bundling issues, and contact optimization.

Contribution

It provides insights into CNT device fabrication, highlighting bundling challenges and identifying palladium as the optimal contact material.

Findings

Bundling is prevalent in CNTs grown over structured slits.

Individual SWNTs are obtainable on rigid supports.

Pd contacts offer the lowest electrical resistance.

Abstract

Using carbon nanotubes (CNTs) produced by chemical vapor deposition, we have explored different strategies for the preparation of carbon nanotube devices suited for electrical and mechanical measurements. Though the target device is a single small diameter CNT, there is compelling evidence for bundling, both for CNTs grown over structured slits and on rigid supports. Whereas the bundling is substantial in the former case, individual single-wall CNTs (SWNTs) can be found in the latter. Our evidence stems from mechanical and electrical measurements on contacted tubes. Furthermore, we report on the fabrication of low-ohmic contacts to SWNTs. We compare Au, Ti and Pd contacts and find that Pd yields the best results.