Related papers: Phonon Band Center: A Robust Descriptor to Capture…
We systematically demonstrate the temperature-dependent thermal transport properties in crystalline Ge$_2$Sb$_2$Te$_5$via first-principles density functional theory-informed linearized Boltzmann transport equation. The investigation,…
While the effect of intrinsic defects on the electronic properties of half-Heusler compounds has been extensively discussed in literature, their effect on the lattice vibrations has received much less attention, due to the prohibitive…
One of the most accurate approaches for calculating lattice thermal conductivity, $\kappa_l$, is solving the Boltzmann transport equation starting from third-order anharmonic force constants. In addition to the underlying approximations of…
IV-VI materials are some of the most efficient bulk thermoelectric materials due to their proximity to soft-mode phase transitions, which leads to low lattice thermal conductivity. It has been shown that the lattice thermal conductivity of…
Effects of strong phonon anharmonicity of a type-I clathrate Ba$_{\rm 8}$Ga$_{\rm 16}$Sn$_{\rm 30}$ induced by quadruple-well potential of guest atoms were investigated. Phonon transport including coherent interbranch component was analyzed…
The authors proposed a simple model for the lattice thermal conductivity of graphene in the framework of Klemens approximation. The Gruneisen parameters were introduced separately for the longitudinal and transverse phonon branches through…
The thermal conductivity of monolayer graphene is an outstanding challenge with no consensus reached on its exact value and length convergence so far. We consider four-phonon scattering, phonon renormalization, and an exact solution to…
Low band gap thermoelectric materials suffer from bipolar effects at high temperatures, with increased electronic thermal conductivity and reduced Seebeck coefficient, leading to reduced power factor and low ZT figure of merit. In this work…
Current phonon transport theory based on ground-state calculations has been successful in predicting thermal conductivity at room and medium temperatures but may misrepresent behavior at high temperatures. In this work, we predict the…
Understanding phonon scattering by topological defects in graphene is of particular interest for thermal management in graphene-based devices. We present a study that quantifies the roles of the different mechanisms governing defect phonon…
The Anderson localization of thermal phonons has been shown only in few nano-structures with strong random disorder by the exponential decay of transmission to zero and a thermal conductivity maximum when increasing system length. In this…
Lattice thermal conductivities of two SiO$_2$ polymorphs, i.e., $\alpha$-quartz (low) and $\alpha$-cristobalite (low), were studied using first-principles anharmonic phonon calculation and linearized phonon Boltzmann transport equation.…
Understanding and simulating the thermodynamic and dynamical properties of materials affected by strong ionic anharmonicity is a central challenge in material science. Much interest is in material displaying critical displacive behaviour,…
The wave property of phonons is employed to explore the thermal transport across a finite periodic array of nano-scatterers such as circular and triangular holes. As thermal phonons are generated in all directions, we study their…
Anomalous thermal expansion behaviour of several open frame-work compounds has been extensively investigated using the techniques of inelastic neutron scattering and lattice dynamics. These compounds involve increasing level of structural…
We review our recent development of a first-principles lattice dynamics method that can treat anharmonic effects nonperturbatively. The method is based on the self-consistent phonon theory and temperature-dependent phonon frequencies can be…
The pure CsPbBr$_3$ perovskite is an archetypal example of a strongly anharmonic crystal that poses a major challenge for computational methods to describe its thermodynamic properties. Its lattice dynamics exhibits characteristics of a…
In this study, we systematically investigate the thermal and electronic transport properties of two-dimensional PbSe/PbTe monolayer heterostructure by combining first-principles calculations, Boltzmann transport theory, and machine learning…
Explicit expressions for anharmonic contributions to the thermodynamic properties with allowance for higher-order phonon-phonon interactions for closed-packed crystals are given, and the calculations for some fcc metals near the melting…
We have implemented a generic method, based on the 2n+1 theorem within density functional perturbation theory, to calculate the anharmonic scattering coefficients among three phonons with arbitrary wavevectors. The method is used to study…