Achieving Enhanced Thermoelectric Performance in (SnTe) 1- x (Sb 2 Te 3 ) x and (SnTe) 1- y (Sb 2 Se 3 ) y Synthesized via Solvothermal Reaction and Sintering

作者：Xiaofang Liu, Bin Zhang, Yao Chen, Hong Wu, Hengyang Wang, Meiling Yang, Guoyu Wang, Jingtao Xu, Xiaoyuan Zhou, Guang Han · 发表于：ACS Applied Materials & Interfaces · 年份：2020 · DOI：10.1021/acsami.0c13651 · 被引用次数：42 · 研究领域：Advanced Thermoelectric Materials and Devices、Chalcogenide Semiconductor Thin Films、Phase-change materials and chalcogenides

SnTe is proposed to be an intriguing low-toxicity alternative to PbTe. Herein, we report the diminished lattice thermal conductivity (κ L ) and enhanced zT of SnTe by way of vacancy engineering. (SnTe) 1- x (Sb 2 Te 3 ) x ( x = 0.03, 0.06, and 0.10) and (SnTe) 1- y (Sb 2 Se 3 ) y ( y = 0.03 and 0.06) were synthesized by blending and sintering their solution-synthesized nano/microstructures (i.e., SnTe octahedral particles, Sb 2 Te 3 nanoplates, and Sb 2 Se 3 nanorods). Benefiting from the chemical reactions during sintering, single-phase SnTe-based solid solutions were formed when x or y is not higher than 0.06, into which tunable concentrations of Sn vacancies were introduced. Such vacancies significantly enhance phonon scattering, leading to the sharply reduced room temperature κ L of 1.40 and 1.26 W m –1 K –1 for x = 0.06 and y = 0.06 samples, respectively, as compared to 3.73 W m –1 K –1 for pristine SnTe. Enabled by point defects with the highest concentration and SnSb 2 Te 4 secondary phase, (SnTe) 0.90 (Sb 2 Te 3 ) 0.10 sample obtains the lowest κ L of 0.70 W m –1 K –1 at 813 K. Ultimately, maximum zT values of 0.6 and 0.7 at 813 K are achieved in (SnTe) 0.90 (Sb 2 Te 3 ) 0.10 and (SnTe) 0.94 (Sb 2 Se 3 ) 0.06, respectively. This study demonstrates the effectiveness of vacancy engineering in improving zT of SnTe-based materials.