Theoretically, carbon nanotubes can conduct 1,000 fold more electric current when compared to a metal conductor of equal size.
Micrograph of recession and clumping in gold electrodes
However, according to recent tests conducted at the National Institute of Standards and Technology (NIST), the reliability of carbon nanotube-based devices poses a major challenge in nanoscale electronic applications.
The NIST scientists created and investigated various carbon nanotube inter links between metal electrodes. The test results revealed that carbon nanotubes can tolerate very high current densities for a considerable number of hours but will gradually degrade under steady current. The metal electrodes fail when currents increase over a specific threshold value, resulting in failure of the circuits in nearly 40 h.
The NIST is devising various measurement and study technologies and is investigating what takes place at the interfaces of metals and nanotubes and between various nanotubes. In another associated study, the researchers observed failures in carbon nanotube networks where electrons physically move from one tube to the other.
NIST researchers devised electrical stress tests, which relate forecast of failure, preliminary resistance to rate of degradation and total operating life of the device. The tests can be utilized to improve the creation and consistency of nanotube networks. NIST postdoctoral researcher, Mark Strus believes that carbon nanotube networks would be suitable for certain electronic applications. They can be used as interlinks for photovoltaics or flexible electronic displays, he said. Largely, the NIST tests will make nanotube materials to qualify for future-generation electronics. It will assist process developers in determining whether the structure will sustain increased levels of electric current and alter processing in order to optimize reliability and performance.