Abstract
It is reported that electron doped n-type SnSe2 nanoplates show promising thermoelectric performance at medium temperatures. After simultaneous introduction of Se deficiency and Cl doping, the Fermi level of SnSe2 shifts toward the conduction band, resulting in two orders of magnitude increase in carrier concentration and a transition to degenerate transport behavior. In addition, all-scale hierarchical phonon scattering centers, such as point defects, nanograin boundaries, stacking faults, and the layered nanostructures, cooperate to produce very low lattice thermal conductivity. As a result, an enhanced in-plane thermoelectric figure of merit ZTmax of 0.63 is achieved for a 1.5 at% Cl doped SnSe1.95 pellet at 673 K, which is much higher than the corresponding in-plane ZT of pure SnSe2 (0.08).
Original language | English (US) |
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Article number | 1702167 |
Journal | Advanced Energy Materials |
Volume | 8 |
Issue number | 8 |
DOIs | |
State | Published - Mar 15 2018 |
Funding
The authors gratefully acknowledge Singapore MOE AcRF Tier 1 under Grant Nos. RG 113/15 and 2016-T1-002-065, Singapore A*STAR Pharos Program SERC 1527200022. This work was supported by the National Research Foundation Singapore under the Corp Lab @ University Scheme and National Natural Science Foundation of China (Grant no. 61728401). The technical assistance (TEM JEOL 2100F, FESEM JEOL 7600 and XRD Bruker D8 advance) from the FACTS (Facility for Analysis, Characterization, Testing, and Simulation) of Nanyang Technological University is likewise gratefully acknowledged. At Northwestern work was supported by a grant by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences under Award No. DESC0014520 (electronic structure calculations, sample measurements, and characterization).
Keywords
- Se deficiency
- SnSe
- chlorine doping
- nanoplate orientation
- thermoelectric
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- General Materials Science