Journal Article

High thermoelectric performance by resonant dopant indium in nanostructured SnTe

Lan, Yucheng, Lukas, Kevin, Opeil, Cyril, Chen, Gang, Esfarjani, Keivan, Broido, David, Zhang, Qian, Liao, Bolin, Liu, Weishu, Ren, Zhifeng

2013

Overview

From an environmental perspective, lead-free SnTe would be preferable for solid-state waste heat recovery if its thermoelectric figure-of-merit could be brought close to that of the lead-containing chalcogenides. In this work, we studied the thermoelectric properties of nanostructured SnTe with different dopants, and found indium-doped SnTe showed extraordinarily large Seebeck coefficients that cannot be explained properly by the conventional two-valence band model. We attributed this enhancement of Seebeck coefficients to resonant levels created by the indium impurities inside the valence band, supported by the first-principles simulations. This, together with the lower thermal conductivity resulting from the decreased grain size by ball milling and hot pressing, improved both the peak and average nondimensional figure-of-merit (ZT) significantly. A peak ZT of ∼1.1 was obtained in 0.25 atom % In-doped SnTe at about 873 K.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Alloys / Atoms / Ball milling / Charge carriers / Doping / Electric Conductivity / Electric properties / Electrical resistivity / heat / Heat conductivity / Heat recovery / Hot pressing / Indium / Iridium - chemistry / Materials Testing / Melting / Microscopy, Electron, Scanning / milling / Models, Chemical / Nanostructures - chemistry / Physical Sciences / pressing / Seebeck effect / Simulation / solar (photovoltaic), solar (thermal), solid state lighting, phonons, thermal conductivity, thermoelectric, defects, mechanical behavior, charge transport, spin dynamics, materials and chemistry by design, optics, synthesis (novel materials), synthesis (self-assembly), synthesis (scalable processing) / Tellurium - chemistry / Temperature / Thermal conductivity / Thermoelectric power generation / Tin Compounds - chemistry / Waste recovery / X-Ray Diffraction