What makes the new material attractive is that it not only has high conductivity, but also has a wide bandgap, which makes it optically transparent. “The high conductivity and wide bandgap make this an ideal material for making optically transparent conducting films, which could be used in a variety of electronic devices, including high power electronics, electronic displays and touchscreens,” said Professor Bharat Jalan.
The researchers developed the transparent conducting thin film by growing a BaSnO3 thin film, but with the elemental tin source replaced by a chemical precursor of tin. This, the team notes, has radical properties that enhance the chemical reactivity and improve the metal oxide formation process. A further benefit is that barium and tin are cheaper than indium – currently used in transparent devices – and are abundant.
According to the scientists, their approach brought ‘unprecedented control over thickness, composition and defect concentration’, addingthe process should be suitable for other material systems where the element is hard to oxidise.
“Even though this material has the highest conductivity within the same materials class,” Prof Jalan continued, “there is much room for improvement, in addition to the potential for discovering new physics if we decrease the defects. That’s our next goal.”
