Competing Grain Growth Pathways in Anisotropic BiTe-Based Thermoelectric Nanoplates.

Thermoelectric nanoplates derived from anisotropic van der Waals (vdW) materials such as BiTe are pivotal for flexible electronics and microscale thermal management. Their performance critically depends on grain boundary (GB) microstructure, but the atomic-scale mechanisms governing grain growth in these highly anisotropic systems remain elusive. This particularly concerns the competition between individual nanoplate reshaping driven by facet stabilization and collective merging at GBs.

Revealing disorder parameter and deformation electron density using electron diffraction.

Local disorders of lattice, charge, orbital, and spin perturbate the electron density distribution in materials, profoundly influencing their properties. Consequently, experimental determination of local electron density offers a powerful, universal approach to probe such disorder. Although quantitative convergent beam electron diffraction (QCBED) is widely employed for electron density measurements in ordered crystals, its applicability to disordered structures, where the translational symmetry of the electrostatic potential is broken, remains uncertain.

Atomic-Resolution Interfacial Reaction Mechanism between BiTe-Based Alloys and Ni Electrodes.

Interdiffusion and solid-solid phase reaction at the interface between thermoelectric (TE) materials and the electrode critically influence interfacial transport properties and the overall energy conversion efficiency during service. Here, the microstructural evolution and diffusion mechanisms at the interfaces between the most widely used BiTe-based TE materials, n-type BiTeSe (BTS) and p-type BiSbTe (BST), and Ni electrodes were investigated at atomic resolution using spherical aberration-corrected scanning transmission electron microscopy (STEM). The BTS(0001)/Ni and BST(0001)/Ni interfaces were constructed by depositing Ni nanoparticles on mechanically exfoliated BTS and BST bulk materials and subsequent annealing.