Hg Doping Induced Reduction in Structural Disorder Enhances the Thermoelectric Performance in AgSbTe2

• DOI: 10.1021/jacs.3c09643
• Publication Date: 2023-11-09T10:59:50Z
• Authors: Animesh Bhui; Subarna Das; Raagya Arora; Usha Bhat; Prabir Dutta; Tanmoy Ghosh; Riddhimoy Pathak; Ranjan Datta; Umesh V. Waghmare; Kanishka Biswas
• Keywords: Figure of Merit; Phonon scattering

Defect engineering, achieved by precise tuning of the atomic disorder within crystalline solids, forms a cornerstone structural chemistry. This nuanced approach holds potential to significantly augment thermoelectric performance synergistically manipulating interplay between charge carrier and lattice dynamics. Here, current study presents distinctive investigation wherein introduction Hg doping into AgSbTe2 serves partially curtail disorder. strategic maneuver mitigates fluctuations originating from pronounced size disparities Ag+ Sb3+, positioned in octahedral sites rock salt structure. improves phase stability restricting congenital emergence Ag2Te minor secondary promotes partial ordering cation sublattice. Reduction coalesced with complementary modification electronic structure results increased mobility. The formation nanoscale superstructure sizes (2-5 nm) order phonon mean free path is further promoted reduced disorder, causes enhanced scattering heat-carrying phonons, glass-like ultralow thermal conductivity (∼0.32 W m-1 K-1 at 297 K). Cumulatively, multifaceted influence doping, conjunction consequential reduction allows achieving high figure-of-merit, zT, ∼2.4 ∼570 K. result defies conventional paradigms that prioritize for optimizing zT.