Remarkable Improvement of Thermoelectric Figure-of-Merit in SnTe through In Situ-Created Te Nanoinclusions

• DOI: 10.1021/acsaem.0c01156
• Publication Date: 2020-07-01T14:51:50Z
• Authors: Sajid Ahmad; Ajay Singh; Shovit Bhattacharya; M. Navaneethan; Ranita Basu; Ranu Bhatt; Pritam Sarkar; K. N. Meshram; K. P. Muthe; Satish Vitta; D. K. Aswal
• Keywords: Phonon scattering; Figure of Merit

SnTe exhibits very low Seebeck coefficient along with high electrical–thermal conductivities owing to hole concentration that results from intrinsic Sn vacancies. All these unfavorable thermoelectric parameters restrict pristine becoming an outstanding material. In this work, we demonstrate the improvement in figure-of-merit of through situ creation Te nanoinclusions matrix. We have intentionally added excess stoichiometric Sn/Te (1:1) for synthesis SnTe. During solidification melt, liquid state gets expelled grain boundaries. On further cooling, when starts solidify, it exerts strain already solidified grains and creates extensive structural defects including dislocations, twin boundaries, subgrain boundaries scatter phonons midwavelength. The point defect due vacancies SnTe/Te respectively scatters wavelengths. Effective scattering entire spectrum hierarchical gives rise ultralow lattice thermal conductivity 0.5 W m–1 K–1 is close theoretical minimum limit. contribution heavy valence band transport energy filtering charge carriers at interface near room temperature. cumulative effect improved suppressed a (ZT) value ∼1.5 750 K average ZT ∼0.48 Sn0.9Te sample.