Thermoelectric material converts waste heat into electricity

The nanomaterial from KAUST (King Abdullah University of Science and Technology) is made using a low-temperature solution-based production process.

“Among the many renewable energy sources, waste heat has not been widely considered,” said Mohamad Nugraha, a postdoctoral researcher in Derya Baran's lab. Waste heat emitted by machines and devices could be recaptured by thermoelectric materials. These substances have a property that means that when one side of the material is hot and the other is cold, an electric charge builds up along the temperature gradient.

Until now, thermoelectric materials have been made using expensive and energy-intensive processes. Baran, Nugraha and their colleagues have developed a new thermoelectric material made by spin coating a liquid solution of quantum dots.

The team spin coated a thin layer of lead-sulphide quantum dots on a surface and then added a solution of short linker ligands that crosslink the quantum dots together to enhance the material’s electronic properties.

After repeating the spin-coating process layer-by-layer to form a 200nm thick film, gentle thermal annealing dried the film and completed fabrication.