期刊
ENERGY & ENVIRONMENTAL SCIENCE
卷 11, 期 11, 页码 3220-3230出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c8ee01755g
关键词
-
资金
- Department of Energy, Office of Science Basic Energy Sciences [DE-SC0014520]
- DOE Office of Science
- National Natural Science Foundation of China [61728401]
- Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF) [ECCS-1542205]
- MRSEC program at the Materials Research Center [NSF DMR-1720139]
- International Institute for Nanotechnology (IIN)
- Keck Foundation
- State of Illinois through the IIN
- Office of Science of the U.S. Department of Energy [DE-AC02-06CH11357, DE-AC02-05CH11231]
- Singapore MOE AcRF Tier 1 [2016-T1-002-065]
- Singapore A*STAR Pharos Program SERC [1527200022]
- FACTs of Nanyang Technological University
Historically PbSe has underperformed PbTe in thermoelectric efficiency and has been regarded as an inferior relative to its telluride congener. However, the fifty-fold greater natural abundance of Se relative to Te makes PbSe appealing as a thermoelectric material. We report that the n-type GeSe-alloyed PbSe system achieves a peak figure of merit, ZT, of approximate to 1.54 at 773 K and maintains ZT values above 1.2 over a broad temperature range from 623 K to 923 K. The highest performing composition is Sb-doped PbSe-12%GeSe, which exhibits an ultralow lattice thermal conductivity of approximate to 0.36 W m(-1) K-1 at 573 K, close to the limit of amorphous PbSe. Theoretical studies reveal that the alloyed Ge2+ atoms prefer to stay at off-center lattice positions, inducing low frequency modes. The Ge atoms also cause the unexpected behavior where the next nearest atom neighbors (6 Pb atoms) oscillate at lower frequencies than in pure PbSe leading to a large reduction of the Debye temperature and acoustic phonon velocity. The Pb0.9955Sb0.0045Se-12%GeSe system also shows Ge-rich precipitates and many aligned dislocations within its microstructure which also contribute to phonon scattering. The resultant average ZT (ZT(avg)), a broad measure of the material's potential for functional thermoelectric modules, is 1.06 from 400 K to 800 K, the highest among all previously reported n- and p-type PbSe. This value matches or exceeds even those of the best n-type PbTe-based thermoelectric materials.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据