Metavalent chemical bond holds key to enhance the thermoelectric performance in quantum materials

Source: The post is based on the article “Metavalent chemical bond holds key to enhance the thermoelectric performance in quantum materials” published in PIB on 3rd May 2023

What is the News?

Researchers have found that Metavalent bonding can be used to tailor the thermoelectric performance in quantum materials and efficiently convert waste heat to electricity. This could show a new direction for the country’s newly launched Quantum Mission.

What is Metavalent Bonding?

Metavalent bonding is a new type of chemical bonding in solids. They are multicentric soft bonds with less than 2e– shared between the bonding atoms, defying the classical octet rule in chemistry.

They have properties of both the bonding present in metals (for good electrical conductivity) as well as those found in glasses (for low thermal conductivity).

What did researchers find about Metavalent Bonding?

Generating electricity from waste heat holds an exciting prospect for green energy production. 

Finding high-performance thermoelectric materials for this purpose requires materials with a magical recipe of properties that can conduct electricity like a metal, heat like a glass, and exhibit the Seebeck coefficient like a semiconductor.

The performance of a thermoelectric material is evaluated based on a dimensionless index related to electrical resistivity, Seebeck coefficient, and thermal conductivity called zT. 

The higher the zT, the higher is the efficiency. Increasing zT is extremely challenging due to the contradicting interdependences between the material constants that constitute zT, like the electrical and thermal conductivity, Seebeck coefficient, etc.

To overcome this challenging goal, researchers have found that metavalent bonding can be used to tailor the thermoelectric performance in quantum materials and efficiently convert waste heat to electricity.