Jian He in his lab at Clemson University. Photo: Clemson University College of Science.
Jian He in his lab at Clemson University. Photo: Clemson University College of Science.

Thermoelectric materials directly convert heat into electricity and power a wide array of items – from NASA's Perseverance rover currently exploring Mars to travel coolers that chill beverages. Now, a physicist at Clemson University has joined forces with collaborators from China and Denmark to create a new, and potentially paradigm-shifting, high-performance thermoelectric material.

A material's atomic structure determines its properties. Typically, solids are either crystalline or amorphous: in crystals, atoms are arranged in an orderly and symmetrical pattern, whereas in amorphous materials the atoms are randomly distributed.

Clemson researcher Jian He and the international team created a new hybrid thermoelectric material in which crystalline and amorphous sublattices are intertwined to produce a one-of-a-kind crystal-amorphic duality. They report this new thermoelectric material in a paper in Joule.

"Our material is a unique hybrid atomic structure with half being crystalline and half amorphous," said He, an associate professor in the Department of Physics and Astronomy at Clemson University. "If you have a unique or peculiar atomic structure, you would expect to see very unusual properties because properties follow structure."

The researchers created their hybrid material by intentionally mixing elements that are in the same group of the periodic table but have different atomic sizes. Here, they used the atomic size mismatches between sulfur (S) and tellurium (Te) and between copper (Cu) and silver (Ag) to create a new compound (Cu1-xAgx)2(Te1-ySy) in which the crystalline and amorphous sublattices intertwine. This new material exhibits excellent thermoelectric properties.

While this discovery doesn't directly impact applications now, it is likely to lead to better thermoelectrics in the future.

"The new material performs well, but more important than that is how it achieves that level of performance," He said. "Traditionally, thermoelectric materials are crystals. Our material is not pure crystal, and we show we can achieve the same level of performance with a material with a new atomic structure."

He said he expects the new material will begin affecting applications in 10 to 20 years. "They definitely can do something current thermoelectric materials cannot do, but not now," He said. "However, the future of this research is bright."

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