Scientists unlock the thermal secret behind a promising energy material
Researchers have identified why tin selenide (SnSe) converts heat to electricity far more efficiently than expected—a discovery that could accelerate development of thermoelectric devices for power generation and cooling. Understanding this mechanism removes a major barrier to engineering commercial applications in waste heat recovery and thermal management systems.
Originaltitel: Two-Step Phase Transition in SnSe and the Origins of its High Power Factor from First Principles
<p>The interest in improving the thermoelectric response of bulk materials has received a boost after it has been recognized that layered materials, in particular SnSe, show a very large thermoelectric figure of merit. This result has received great attention while it is now possible to conceive other similar materials or experimental methods to improve this value. Before we can now think of engineering this material it is important we understand the basic mechanism that explains this unusual behavior, where very low thermal conductivity and a high thermopower result from a delicate balance between the crystal and electronic structure. In this Letter, we present a complete temperature evolution of the Seebeck coefficient as the material undergoes a soft crystal transformation and its consequences on other properties within SnSe by means of first-principles calculations. Our results are able to explain the full range of considered experimental temperatures.</p>