UK scientists find way to cut down indium

A paper presented by scientists in the U.K. has demonstrated replacing tin with molybdenum in a transparent conductive oxide (TCO) layer could lead to devices that are both thinner and better performing than today’s commercial solar technologies.

In some solar cells, particularly thin film technologies, a TCO layer is used to improve performance. The majority of TCOs are based on indium tin oxide (ITO) and the rarity of indium has been highlighted as a potential problem as demand rises.

In a paper published in Materials Horizons, a team of scientists has demonstrated another material – indium molybdenum oxide (IMO) – exhibits far better conductivity than ITO and can deliver better performance with a layer only half as thick and containing half as much indium.

The results presented in the paper demonstrated using molybdenum as a dopant created better resonance with the conduction band. The researchers said their new understanding of the materials could pave the way for development of further high performance TCO ingredients.

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

The researchers say they will apply their knowledge to the development of tin dioxide as a TCO free of indium and other rare materials.