Molybdenum helps produce better transparent coating for touchscreens

A team of British researchers has made an important design discovery that could dramatically improve the performance of a key material used to coat touchscreens and other devices. The researchers come from the University of Liverpool, University College London (UCL), NSG Group (Pilkington) and the Diamond Light Source, and report their discovery in a paper in Materials Horizons.

Tin-doped indium oxide (ITO) is the leading material used to coat the glass or clear plastic of touchscreens, solar cells and light emitting diodes, because it is one of the few materials that both conducts electricity and allows light through.

ITO accounts for 60% of the multibillion-dollar transparent conducting oxide market and 60% of global indium use. However, efforts to find materials that can replace ITO have increased significantly in recent years, as supplies of indium have decreased and its price has risen significantly.

Now, this team of researchers has made an important design discovery that could lead to films and coatings that don't rely so heavily on this rare element. Using a combination of experimental and theoretical approaches, they found that replacing tin with the transition metal molybdenum creates a vastly superior material – IMO – that has twice the conductivity of ITO. It can deliver better performance than ITO with only half the thickness and half the amount of indium.

"This is an exciting new development in the field of transparent conductors and has the potential of extending the life of the world's indium supplies, which are in increasingly short supply," said Jack Swallow, a PhD student in the University of Liverpool's Department of Physics and the Stephenson Institute for Renewable Energy.

"Our work illustrates the power of combining chemistry and physics experimental approaches with computational materials design," said David Scanlon of UCL, a co-author of the paper.

The researchers now intend to apply their new understanding to finding alternative novel dopants to improve other transparent conductors. This includes tin dioxide, which contains only earth abundant elements and so is cheap enough for large area uses such as solar cells and energy efficient windows.

"Although IMO was first made several years ago, the reason why it is so much better than ITO wasn't understood," said Tim Veal of the University of Liverpool, another co-author of the paper. "Our research finding represents a breakthrough and opens the way for industry to reduce its use of indium in displays and touchscreens, and provides a route for commercial development of better, cheaper transparent conductors for renewable energy applications."

This story is adapted from material from the University of Liverpool, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.