Titanium oxynitride (TiNO) films – thin layers of material made from titanium, oxygen and nitrogen – have long been very useful in engineering applications such as energy-efficient windows and wear-resistant tool coatings. However, scientists have been puzzled by how to best harness TiNO characteristics – their novel interaction with light at various wavelengths – for use in additional applications. Recently, researchers from North Carolina Agricultural and Technical State University (NC A&T) have used U.S. National Science Foundation (NSF) ACCESS allocations on the Bridges-2 system at the Pittsburgh Supercomputing Center, a joint effort between Carnegie Mellon University and the University of Pittsburgh, to simulate the structure of TiNO films and predict properties that are key to their application in sensors, high-speed communication and energy-efficient technologies.

“Our study used ACCESS allocations on Bridges-2 to better understand how structure and composition influence the electronic properties of TiNO films,” explained J. David Schall, an associate professor of mechanical engineering at NC A&T.

The team’s experiments and theoretical models on Bridges-2 both supported these findings – revealing how oxygen content influences TiNO’s electronic behavior.

“In our experiments, we found that increased oxygen content reduced conductivity and increased band gap,” Schall said. “Complementary simulations point to the introduction of shallow trap states the root cause of this behavior.”

“These breakthrough findings are exciting as this offers a tunable bandgap and potential uses in semiconductor applications as TiNO could very well provide a more durable and versatile alternative to noble and refractory metals,” said Dhananjay Kumar, who heads the NSF-PREM center, which supports this research at NC A&T. “Thanks to ACCESS allocations on Bridges-2, we are opening new possibilities for next-generation plasmonic and photonic devices.”

The study has been published in Computational Materials Science and the Journal of Physical Chemistry C.

Resource Provider Institution(s): Pittsburgh Supercomputing Center (PSC)
Resources Used: Bridges-2
Affiliations: North Carolina Agricultural and Technical State University (NC A&T)
Funding Agency: NSF
Grant or Allocation Number(s): MAT220024

The science story featured here was enabled by the U.S. National Science Foundation’s ACCESS program, which is supported by National Science Foundation grants #2138259, #2138286, #2138307, #2137603, and #2138296.