Transparent and conductive: the key to cheaper electronics

A new nano-scale thin film material has been discovered with the highest-ever conductivity in its class, holding potential for both smaller, faster, and more powerful electronics, as well as more efficient solar cells.

A new nano-scale thin film material has been discovered with the highest-ever conductivity in its class, holding potential for both smaller, faster, and more powerful electronics, as well as more efficient solar cells.

The researchers from the University of Minnesota say what makes the material unique is its combination of high conductivity and a wide bandgap, which means light can easily pass through the material making it optically transparent. In most cases, materials with wide bandgap, usually have either low conductivity or poor transparency.

“The high conductivity and wide bandgap make this an ideal material for making optically transparent conducting films which could be used in a wide variety of electronic devices, including high power electronics, electronic displays, touchscreens and even solar cells in which light needs to pass through the device,” said Bharat Jalan, a chemical engineering and materials science professor from the University of Minnesota.

Currently, most of the transparent conductors in our electronics use a chemical element called indium. However, its price has increased significantly over the past two decades, which has added to the cost of current display technology. As a result, there has been tremendous effort to find alternative materials that work as well, or even better, than indium-based transparent conductors.

The team developed their transparent conducting thin film using a new synthesis method, in which they grew a barium stannate thin film, but replaced the elemental tin source with a chemical precursor of tin. Its unique, radical properties enhanced the chemical reactivity and greatly improved the metal oxide formation process. Both barium and tin are significantly cheaper than indium and widely available.

“Even though this material has the highest conductivity within the same materials class, there is much room for improvement in addition, to the outstanding potential for discovering new physics if we decrease the defects. That’s our next goal,” Jalan said.

[The new material could reduce the cost of electronic displays or solar cells. Photo: University of Minnesota]

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