Progress to mainstream thermoelectric materials which could recover waste heat

Thermoelectric (TE) materials could play a key role in future technologies. Although the applications of these remarkable compounds have long been explored, they are mostly limited to high-temperature devices. Recently, researchers at Osaka University, in collaboration with Hitachi, Ltd., developed a new TE material with an improved power factor at room temperature. Their study, published in Physica Status Solidi RRL, could help bring these materials out of the high-temperature niche and into the mainstream.

Most TE materials are often based on rare or toxic elements. Osaka Researchers combined silicon – which is common in TE materials – with ytterbium, to create ytterbium silicide [YbSi2]. It is non-toxic.

The researchers believe that heat conduction is further suppressed by controlling the structure in nanoscale and traces of impurities and other defects.

The result is an encouragingly high power factor of 2.2 mWm-1K-2 at room temperature. This is competitive with conventional TE materials based on bismuth telluride.

Thermoelectric materials can be used to generate electricity from waste heat.