Lattice anharmonic dynamics induced ultra-low thermal conductivity of Si doped Ag2S thermoelectric materials
Year: 2026
Type: article
Abstract: Thermoelectric materials hold broad application prospects in waste heat recovery, yet the understanding of the thermal conduction mechanism remained insufficient and limited their development. Si doped Ag 2 S thermoelectric materials had prepared by vacuum electromagnetic induction melting technique with holding temperature at mushy zone, and the thermal transfer mechanism were investigated through anharmonic lattice dynamic analysis. The Ag 2-x Si x S alloys were prepared in one step, with the preparation time reduced to less than 40 min. X-ray diffraction and energy dispersive spectroscopy indicated the formation of major α -Ag 2 S phase and minor Ag 3 S phase. With the increase of Si content, the thermal conductivity ( κ l ) decreased from 0.87 Wm −1 K −1 to 0.38 Wm −1 K −1 at 603 K, exhibited a significant reduction of over 56%. The lowest κ l of 0.29 Wm −1 K −1 was achieved at 431 K with the Si concentration of 15 at%. The anharmonic lattice dynamic calculation revealed Si atoms promoted the high order anharmonicity, the weakening of the optical branch vibration mode caused the ultra-low κ l . The electronic structure calculation showed that doping led to the carriers more localized and reduced the electronic thermal transfer. The overall measurements indicated that Si doping enhanced carrier mobility and suppressed the thermal conductivity without reducing the Seebeck coefficient significantly.
Source: Materials & Design
Institution: Northwestern Polytechnical University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,650
OpenAlex ID: W7163069532