Optimizing Thermoelectric Properties through Compositional Engineering in Ag-Deficient AgSbTe₂ Synthesized by Arc...

Thermoelectric materials offer a promising avenue for energy management, directly converting heat into electrical energy. Among them, AgSbTe₂ has gained significant attention and continues to be a subject of research at further improving its thermoelectric performance and expanding its practical applications. This study focuses on Ag-deficient Ag_0.7Sb_1.12Te₂ and Ag_0.7Sb_1.12Te_1.95Se_0.05 materials, examining the impact of compositional engineering within the AgSbTe₂ thermoelectric system. These materials have been rapidly synthesized using an arc-melting technique, resulting in the production of dense nanostructured pellets. Detailed analysis through scanning electron microscopy (SEM) reveals the presence of a layered nanostructure, which significantly influences the thermoelectric properties of these materials. Synchrotron X-ray diffraction reveals significant changes in the lattice parameters and atomic displacement parameters (ADPs) that suggest a weakening of bond order in the structure. The thermoelectric characterization highlights the enhanced power factor of Ag-deficient materials that, combined with the low glass-like thermal conductivity, results in a significant improvement in the figure of merit, achieving values of 1.25 in Ag_0.7Sb_1.12Te₂ and 1.01 in Ag_0.7Sb_1.12Te_1.95Se_0.05 at 750 K.