相关论文: Anharmonic stabilization and lattice heat transpor…
We investigate the microscopic mechanism of ultralow lattice thermal conductivity ($\kappa_l$) of TlInTe$_2$ and its weak temperature dependence using a unified theory of lattice heat transport that considers contributions arising from the…
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,…
MgAgSb, a promising thermoelectric material, undergoes reversible phase transitions that drastically alter its thermal transport behavior. Using first-principles calculations, we systematically investigate the lattice thermal conductivity…
PbTe, one of the most promising thermoelectric materials, has recently demonstrated thermoelectric figure of merit ($ZT$) of above 2.0 when alloyed with group II elements. The improvements are due mainly to significant reduction of lattice…
The proximity to structural phase transitions in IV-VI thermoelectric materials is one of the main reasons for their large phonon anharmonicity and intrinsically low lattice thermal conductivity $\kappa$. However, the $\kappa$ of GeTe…
Crystalline compounds exhibiting low-frequency rattling phonons constitute an important class of high-performance thermoelectrics owning to their intrinsically very low lattice thermal conductivity ($\kappa_{l}$). Theoretical approach that…
Understanding the microscopic processes affecting the bulk thermal conductivity is crucial to develop more efficient thermoelectric materials. PbTe is currently one of the leading thermoelectric materials, largely thanks to its low thermal…
We report the discovery of temperature-invariant ultralow thermal conductivity ($\kappa$) in monolayer $\beta'$-In$_2$Se$_3$, a two-dimensional ferroelectric crystal with in-plane polarization. Using a combination of generalized Wigner…
Lattice thermal conductivities (LTCs) of \alpha-, \beta-, and \gamma-Si$_3$N$_4$ single crystals are investigated from ab initio anharmonic lattice dynamics, within the single-mode relaxation-time approximation of the linearized phonon…
$\beta-Ga_2O_3$ is a promising material candidate for next-generation high power devices even as its low thermal conductivity ($\kappa$) limits utilization due to an inability to sufficiently dissipate heat. Despite its importance, a…
Understanding heat transport in semiconductors and insulators is of fundamental importance because of its technological impact in electronics and renewable energy harvesting and conversion. Anharmonic Lattice Dynamics provides a powerful…
The impact of Ge vacancies on the low-temperature lattice dynamics of single-crystalline GeTe was investigated through a comparative study of two off-stoichiometric samples: Ge$_{0.8}$Te (S$_1$) and Ge$_{0.88}$Te (S$_2$). X-ray diffraction…
A first-principles density functional method along with the direct solution of linearized Boltzmann transport equations are employed to systematically analyze the low-temperature thermal transport in crystalline GeTe. The extensive thermal…
Layered perovskite lithium yttrium titanate ($\rm LiYTiO_4$) has recently emerged as a promising low-potential, ultrahigh-rate intercalation-type anode material for lithium-ion batteries; however, its lattice dynamics and thermal transport…
Materials based on cubic tetrahedrites (Cu$_{12}$Sb$_{4}$S$_{13}$) are useful thermoelectrics with unusual thermal and electrical transport properties, such as very low and nearly temperature-independent lattice thermal conductivity…
The search for materials with intrinsically low thermal conductivity ($\kappa_L$) is critical for energy applications, yet conventional descriptors often fail to capture the complex interplay between bonding and lattice dynamics. Here,…
Excitations and scatterings among the quantized lattice vibrations, i.e., phonons, govern the lattice thermal conductivity ($\kappa_l$) in crystalline solids. Therefore, effective modulation of $\kappa_l$ can be achieved through selective…
The anharmonic phonon properties of type-I filled inorganic clathrates Ba8 Ga16 Ge30 and Sr8 Ga16 Ge30 are obtained from the first-principles calculations by considering the temperature-dependent sampling of the potential energy surface and…
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…
We investigate the role of the quartic anharmonicity in lattice dynamics and thermal transport of type-I clathrate Ba$_{8}$Ga$_{16}$Ge$_{30}$ based on \textit{ab initio} self-consistent phonon calculations. We show that the strong quartic…