Shuwei Tang

Interlayer modulation of layered oxychalcogenide superlattices provides a strategy to decouple electron–phonon transport for high-performance thermoelectric (TE) materials. Herein, an intercalated oxychalcogenide superlattice (La4Bi2Ag2Se2Te2O6) is theoretically designed by inserting a La2O2Te slab into the BiAgSeO framework to synergistically optimize carrier and phonon transport behaviors and systematically uncover an unprecedented synergy of orbital-driven valence band degeneracy and Ag+ liquid-like ionic dynamics. The La4Bi2Ag2Se2Te2O6 superlattice exhibits a highly anisotropic lattice architecture characterized by strong intralayer covalent bonding and weak interlayer interactions, which simultaneously preserves structural stability and promotes pronounced lattice anharmonicity. Meanwhile, stereochemically active Bi 6s2 lone-pair electrons, four-phonon scattering, and phonon–diffuson conversion drastically suppress the lattice thermal conductivity. This work establishes a dual-regulation intercalation paradigm combining band convergence and liquid-cation dynamics, offering a universal route for designing high-efficiency layered TE materials.

Two-dimensional MgAl ₂ Se ₄ selenide exhibits intrinsically low lattice thermal conductivity originating from strong phonon anharmonicity, high-frequency phonon scattering, and intrinsic bonding asymmetry.

The structural stability, electronic characteristics, and lithium storage behavior of Sn _x Co _y clusters confined in bilayer graphene are revealed by first-principles calculations, highlighting their potential relevance to anode materials.

Layered rare-earth oxides have become promising candidates for high-performance thermoelectric (TE) materials on account of the distinctive electronic structures and anisotropic transport properties. In this work, the phonon dynamics, carrier transport, and TE performance of the layered SmZnSbO compound are comprehensively evaluated using first-principles calculations, machine learning interatomic potentials, Boltzmann transport theory, and the two-channel model. The coexistence of weak interlayer van der Waals interactions, robust intralayer covalent bonding interactions, and rattling-like vibrations of Zn atoms synergistically induces significant lattice anharmonicity, resulting in a decreased lattice thermal conductivity (0.84 W/mK@900 K within the framework of the two-channel model) for the SmZnSbO compound. The natural quantum well architecture formed by the alternative conductive [Zn2Sb2]2− layer and the insulated [Sm2O2]2+ layer endows quasi-two-dimensional transport characteristics, enabling a high carrier mobility of 34.1 cm2/Vs. Moreover, the multi-valley electronic band structure with an indirect bandgap of 0.80 eV simultaneously optimizes electrical conductivity (σ) and Seebeck coefficient (S), resulting in an enhanced power factor. Benefiting from these synergistic features, the layered SmZnSbO compound achieves optimal dimensionless figures of merit (ZTs) of 1.47 and 1.40 for the p-type and n-type doping circumstances at 900 K. The current work not only elucidates the thermal and electronic transport mechanisms for the SmZnSbO compound but also establishes a paradigm for designing high-efficiency layered oxide TE materials through combined strategies of quantum confinement, phonon engineering, and multi-valley band convergence.

Rattling-like atomic vibrations induce pronounced lattice softening and enhanced anharmonicity, yielding an optimized thermoelectric figure of merit ( ZT ) of 1.5 for the CaLiBi compound at 600 K.