Origin of Intrinsically Low Lattice Thermal Conductivity in Solids

Reducing lattice thermal conductivity through external modulation techniques such as defect engineering may potentially interfere with electronic transport. Materials with intrinsically low lattice thermal conductivity have the potential to decouple the control of lattice heat transport and electronic transport, which is of great significance in the field of thermoelectric energy conversion. This paper reviews the origin of intrinsically low lattice thermal conductivity, which is directly related to three physical quantities (heat capacity, phonon group velocity, and phonon relaxation time) and is ultimately reflected in the lattice structure and bonding characteristics. An understanding of the fundamental nature of low lattice thermal conductivity can aid in guiding experimental design and theoretically enabling high-throughput prediction of novel low lattice thermal conductivity materials according to the intrinsic properties.