Research charts the way to more reliable carbon-based microelectronics

June 15, 2018, Georgia Institute of Technology
Credit: Georgia Tech Institute for Electronics and Nanotechnology

Carbon nanotubes – cylindrical formations of carbon atoms with incredible strength and electrical conductivity – hold great promise for creating new micron-scale low-power electronic devices.

But finding a way to build a reliable computing platform based on the material has been a major challenge for researchers.

Now, a team of mechanical and materials engineers at Georgia Institute of Technology has devised a method for identifying variabilities in transistors made from carbon nanotube networks. The new approach could help researchers create more reliable devices and ultimately harness that technology for a range of applications such as wearable electronics, sensors and antennas.

"Using carbon nanotubes to make thin-film transistors with good performance repeatability has been challenging because of the random imperfections in the fabrication process," said Satish Kumar, an associate professor in the George W. Woodruff School of Mechanical Engineering. "Those random imperfections cause variations in the properties of the nanotubes – differences in length, diameter and chirality. All of those things can impact how conductive a nanotube is, which leads to these performance variations.

"What we've done now is created a systematic way to estimate these variations that could improve reliability for carbon nanotube network based devices," he said.

Results from the study, which was sponsored by the National Science Foundation, were published in March in IEEE Transactions on Nanotechnology.

Credit: Georgia Tech Institute for Electronics and Nanotechnology

While earlier research has looked at how to improve production methods for carbon nanotubes in order to achieve more uniformity, Kumar's team focused on analyzing performance variabilities in statistical way so that performance characteristics could be more estimable.

"Such analysis is crucial to explore the reliability and stability of network based circuits and to devise techniques which can help reduce variability in circuit performance for various electronic applications," Kumar wrote with in the paper with Jialuo Chen, a graduate student at Georgia Tech.

While some carbon nanotubes conduct electricity much in the same way that a semiconductor such as silicon, certain carbon nanotubes have conductivity properties more similar to metal. The latter types are called metallic carbon nanotubes. The prevalence of such metallic carbon nanotubes in a network is linked to performance problems.

The study found that the metallic-property carbon nanotubes caused performance variations more so in thin-film transistors with short channels than those with long channels, which means device designers could achieve higher performance by using networks that have a higher concentration of long channel thin-film transistors.

The researchers also found that variations in length of the carbon nanotubes seemed to have less impact on performance as long as the of was dense.

"Our results show that the performance variability of can be reconstructed using the distribution function of relevant parameters which will help us to create more reliable circuits to enable the next generation of low-cost flexible microelectronics," Kumar said.

Explore further: Carbon nanotube finding could lead to flexible electronics with longer battery life

More information: Jialuo Chen et al. Variability in Output Characteristics of Single-Walled Carbon Nanotube Thin-Film Transistors, IEEE Transactions on Nanotechnology (2018). DOI: 10.1109/TNANO.2018.2803106

Related Stories

For first time, carbon nanotube transistors outperform silicon

September 2, 2016

For decades, scientists have tried to harness the unique properties of carbon nanotubes to create high-performance electronics that are faster or consume less power—resulting in longer battery life, faster wireless communication ...

How carbon nanotubes could be used in future electronic devices

November 22, 2017

A team of Skoltech scientists, in collaboration with researchers from the IBM Watson Research Center, have shed light on the behavior of electrical contacts in carbon semiconductor nanotubes, which could pave the way to next-generation ...

Recommended for you

Archaeologists discover Incan tomb in Peru

February 16, 2019

Peruvian archaeologists discovered an Incan tomb in the north of the country where an elite member of the pre-Columbian empire was buried, one of the investigators announced Friday.

Where is the universe hiding its missing mass?

February 15, 2019

Astronomers have spent decades looking for something that sounds like it would be hard to miss: about a third of the "normal" matter in the Universe. New results from NASA's Chandra X-ray Observatory may have helped them ...

What rising seas mean for local economies

February 15, 2019

Impacts from climate change are not always easy to see. But for many local businesses in coastal communities across the United States, the evidence is right outside their doors—or in their parking lots.

The friendly extortioner takes it all

February 15, 2019

Cooperating with other people makes many things easier. However, competition is also a characteristic aspect of our society. In their struggle for contracts and positions, people have to be more successful than their competitors ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.