Journal ArticleDOI
Silicon nanowires as efficient thermoelectric materials
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TLDR
Independent measurements of the Seebeck coefficient, the electrical conductivity and the thermal conductivity, combined with theory, indicate that the improved efficiency originates from phonon effects, and these results are expected to apply to other classes of semiconductor nanomaterials.Abstract:
Thermoelectric materials, capable of converting a thermal gradient to an electric field and vice versa, could be useful in power generation and refrigeration. But the fabrication of the available high-performance thermoelectric materials is not easily scaled up to the volumes needed for large-scale heat energy scavenging applications. Nanostructuring improves thermoelectric capabilities of some materials, but good thermoelectric materials tend not to take readily to nanostructuring. How about silicon? It can be processed on a large scale but has poor thermoelectric properties. Two groups now show that silicon's thermoelectric properties can be vastly improved by structuring it into arrays of nanowires and carefully controlling nanowire morphology and doping. So with more development, silicon may have potential as a thermoelectric material. Thermoelectric materials interconvert thermal gradients and electric fields for power generation or for refrigeration1,2. Thermoelectrics currently find only niche applications because of their limited efficiency, which is measured by the dimensionless parameter ZT—a function of the Seebeck coefficient or thermoelectric power, and of the electrical and thermal conductivities. Maximizing ZT is challenging because optimizing one physical parameter often adversely affects another3. Several groups have achieved significant improvements in ZT through multi-component nanostructured thermoelectrics4,5,6, such as Bi2Te3/Sb2Te3 thin-film superlattices, or embedded PbSeTe quantum dot superlattices. Here we report efficient thermoelectric performance from the single-component system of silicon nanowires for cross-sectional areas of 10 nm × 20 nm and 20 nm × 20 nm. By varying the nanowire size and impurity doping levels, ZT values representing an approximately 100-fold improvement over bulk Si are achieved over a broad temperature range, including ZT ≈ 1 at 200 K. Independent measurements of the Seebeck coefficient, the electrical conductivity and the thermal conductivity, combined with theory, indicate that the improved efficiency originates from phonon effects. These results are expected to apply to other classes of semiconductor nanomaterials.read more
Citations
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Complex thermoelectric materials.
TL;DR: A new era of complex thermoelectric materials is approaching because of modern synthesis and characterization techniques, particularly for nanoscale materials, and the strategies used to improve the thermopower and reduce the thermal conductivity are reviewed.
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Cooling, heating, generating power, and recovering waste heat with thermoelectric systems.
TL;DR: Thermoelectric materials are solid-state energy converters whose combination of thermal, electrical, and semiconductor properties allows them to be used to convert waste heat into electricity or electrical power directly into cooling and heating.
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Prospects of Colloidal Nanocrystals for Electronic and Optoelectronic Applications
TL;DR: Nanocrystals (NCs) discussed in this Review are tiny crystals of metals, semiconductors, and magnetic material consisting of hundreds to a few thousand atoms each that are among the hottest research topics of the last decades.
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Bulk nanostructured thermoelectric materials: current research and future prospects
TL;DR: In this paper, the authors introduce the principles and present status of bulk nanostructured materials, then describe some of the unanswered questions about carrier transport and how current research is addressing these questions.
Journal ArticleDOI
Semiconductor nanowires for energy conversion.
Allon I. Hochbaum,Peidong Yang +1 more
TL;DR: It is discovered that the thermoconductivity of the silicon nanowires can be significantly reduced due to phonon scattering, pointing to a very promising approach to design better thermoelectrical materials.
References
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TL;DR: The theory of the slipline field is used in this article to solve the problem of stable and non-stressed problems in plane strains in a plane-strain scenario.
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TL;DR: The equilibrium of rods and plates Elastic waves Dislocations Thermal conduction and viscosity in solids Mechanics of liquid crystals Index as discussed by the authors The equilibrium of rod and plate elastic waves Elastic waves
Journal ArticleDOI
Thin-film thermoelectric devices with high room-temperature figures of merit
TL;DR: Th thin-film thermoelectric materials are reported that demonstrate a significant enhancement in ZT at 300 K, compared to state-of-the-art bulk Bi2Te3 alloys, and the combination of performance, power density and speed achieved in these materials will lead to diverse technological applications.
Journal ArticleDOI
A laser ablation method for the synthesis of crystalline semiconductor nanowires
TL;DR: Studies carried out with different conditions and catalyst materials confirmed the central details of the growth mechanism and suggest that well-established phase diagrams can be used to predict rationally catalyst materials and growth conditions for the preparation of nanowires.
Journal ArticleDOI
Cubic AgPbmSbTe2+m: Bulk Thermoelectric Materials with High Figure of Merit
Kuei Fang Hsu,Sim Loo,Fu Guo,Wei Chen,Jeffrey S. Dyck,Ctirad Uher,Timothy P. Hogan,Efstathios K. Polychroniadis,Mercouri G. Kanatzidis +8 more
TL;DR: In the temperature range 600 to 900 kelvin, the AgPbmSbTe2+m material is expected to outperform all reported bulk thermoelectrics, thereby earmarking it as a material system for potential use in efficient thermoeLECTric power generation from heat sources.