Origin of Intrinsically Low Lattice Thermal Conductivity in Solids

Area of Science:

• Materials Science
• Solid State Physics
• Energy Conversion

Background:

• External modulation of lattice thermal conductivity can impede electronic transport.
• Materials with intrinsic low lattice thermal conductivity are crucial for thermoelectric devices.
• Decoupling heat and charge transport is key for efficient thermoelectric energy conversion.

Purpose of the Study:

• To review the origins of intrinsically low lattice thermal conductivity.
• To elucidate the relationship between material properties and lattice thermal conductivity.
• To guide the discovery of novel thermoelectric materials.

Main Methods:

• Review of fundamental physical quantities influencing lattice thermal conductivity (heat capacity, phonon group velocity, phonon relaxation time).
• Analysis of the link between lattice structure, bonding characteristics, and thermal transport.
• Discussion of theoretical approaches for material prediction.

Main Results:

• Intrinsically low lattice thermal conductivity originates from specific combinations of heat capacity, phonon group velocity, and phonon relaxation time.
• Lattice structure and bonding characteristics are fundamental determinants of these properties.
• Understanding these origins enables targeted material design.

Conclusions:

• Intrinsic properties offer a pathway to decouple thermal and electronic transport.
• Knowledge of fundamental origins facilitates the design of advanced thermoelectric materials.
• This understanding supports high-throughput prediction and experimental guidance for novel materials.