Novel approach utilizes high mobility two-dimensional electron gas, boosting thermoelectric conversion efficiency.
Novel approach utilizes high mobility two-dimensional electron gas, boosting thermoelectric conversion efficiency.
More than 60% of the energy produced by fossil fuels is lost as heat. Thermoelectric energy conversion has attracted much attention as a way to convert waste heat from power plants, factories and cars into electricity. However, currently available technologies need improvement to become viable on industrial scales.
Researchers at Hokkaido University in Japan have proposed the use of high mobility electrons generated at a semiconductor interface called 2D electron gas (2DEG), which can improve the ability of thermoelectric materials to convert heat energy into electricity.
The researchers made a transistor on the 2DEG at the interface between two semiconducting materials, aluminum gallium nitride and gallium nitride. When an electric field was applied, concentrations of 2DEG could be modulated without reducing its high mobility. The 2DEG’s “power factor,” which is a measure of its electric power, is two to six times higher than most state-of-the-art thermoelectric materials.
Read more at Hokkaido University
Image: (a) In conventional semiconductors, electrons flow from the hot to the cold side with low mobility caused by ionized impurity. (b) In the newly developed semiconductor without the impurity, 2DEG can flow with high mobility. (Credit: Ohta H. et al., Advanced Science, November 20, 2017)
