The discovery of thermoelectric material offers the opportunity for new forms of electric power in the future

Thermoelectric conversion of heat directly into electricity and drives a wide range of articles – from NASA’s Perseverance Rover which is currently exploring Mars to travel coolers that cool drinks.

A physicist from Clemson University has joined forces with collaborators from China and Denmark to create a new and potentially paradigm-shifting, high-performance thermoelectric connection.

The atomic structure of a material, that is, how atoms arrange themselves in space and time, determines its properties. Solids are usually crystalline or amorphous. In crystals, atoms have an orderly and symmetrical pattern. Amorphous materials have randomly scattered atoms.

Clianon researcher Jian He and the international team have created a new hybrid connection in which the crystalline and amorphous sub-grids are intertwined into a unique crystal-amorphous duality.

“Our material is a unique hybrid atomic structure, half of which is crystalline and half amorphous,” said He, an associate professor in the Department of Physics and Astronomy at the College of Science. “If you have a unique or peculiar atomic structure, you would expect to see many unusual properties because properties follow the structure.”

The high-profile energy research journal Joule published their findings in a paper entitled “Thermo-electric materials with crystal-amorphicity duality induced by large atomic size mismatch”, which appeared online on April 16 before the May 19 issue.

The researchers created their hybrid material by deliberately mixing elements in the same group on the periodic table, but with different atomic sizes. Here they used the atomic size similarities between sulfur and tellurium and between copper and silver to create a new compound (Cu1-xAgx) 2 (Te1-ySy) in which the crystalline and amorphous sub-lattices in a unique kind of interwoven duality of crystal -morphism. The new compound showed excellent thermoelectric performance.

Although this discovery does not now have a direct impact on the application, it is likely to lead to better thermoelectricity in the future.

“The new material performs well, but more importantly than it is how it reaches the performance level,” he said. “Traditionally, thermoelectric materials are crystals. Our materials are not pure crystals, and we show that we can achieve the same performance with a material with a new atomic structure.”

He said he expects the new material to be applicable in ten to twenty years.

“They can definitely do something that current thermoelectric materials cannot do, but not now,” he said. “However, the future of this research is bright.”

In addition, He involved scientists from Shanghai Jiaotong University, Shanghai Institute of Ceramics and SUSTech in China and Aarhus University in Denmark.