University of Colorado Boulder scientists have found a creative way to radically improve thermoelectric materials, a finding that could one day lead to the development of improved solar panels, more energy-efficient cooling equipment, and even the creation of new devices that could turn the vast amounts of heat wasted at power plants into more electricity.

The new concept involves building an array of nanoscale pillars on top of a sheet of a thermoelectric material, such as silicon, to form what the authors call a “nanophononic metamaterial.” Heat is carried through the material as a series of vibrations, known as phonons. The atoms making up the miniature pillars also vibrate at a variety of frequencies.

A computer model showed that the vibrations of the pillars would interact with the vibrations of the phonons, slowing down the flow of heat. The pillar vibrations are not expected to affect the electric current.

“If we can improve thermoelectric energy conversion significantly, there will be all kinds of important practical applications,” said Mahmoud Hussein, an assistant professor of aerospace engineering sciences. Applications include recapturing the waste heat emitted by different types of equipment—from laptops to cars to power plants—and turning that heat into electricity. Better thermoelectrics also could vastly improve the efficiency of solar panels and refrigeration devices.


Also: Learn about a Energy-Based Tetrahedron Sensor.