DocumentCode :
2197667
Title :
Impact of contact resistances on the low-dimensional scaling of thermoelectric energy conversion devices
Author :
Pettes, A.M. ; Melamud, R. ; Higuchi, S. ; Goodson, K.E.
Author_Institution :
Dept. of Mech. Eng., Stanford Univ., Stanford, CA
fYear :
2007
fDate :
3-7 June 2007
Firstpage :
283
Lastpage :
289
Abstract :
Thermoelectric energy conversion devices have several advantages relative to alternative heat removal and energy harvesting technologies-they are free of moving parts, acoustically silent, highly reliable and compatible with on-chip integration. Yet their historically limited performance and low efficiency in comparison with alternative technologies have restricted their use from more widespread applications. Previous work has made significant improvements in the low-dimensional figure of merit for several thermoelectric materials, such as superlattice, quantum dot, and skutterite thin-films. Electrical and thermal contact resistances at these length scales, however, have limited the impacts of these advances in material properties so severely that practical devices with high efficiency have yet to be developed. Whereas past work has focused extensively on the enhancement of material rather than interface properties, this work aims to quantify the impact of electrical and thermal contact resistances on device performance and efficiency at low-dimensions. Effective expressions for thermal conductivity, electrical conductivity, and figure of merit of the thermoelectric pellet are presented to account for electrical and thermal interfacial effects at the pellet-interconnect interfaces. Contact resistances are determined for various semiconductor-metal interfaces. Implications of the results are illustrated for the performance and efficiency of two classes of representative thermoelectric devices-bulk and on-chip thermoelectric cooling and energy harvesting devices. For practically achievable values of modern Bi2Te3s heat exchangers, the impact of modern parasitic resistances results in a 50% reduction in the figure of merit at length scales less than ~0.5 mum. The furthered understanding and mitigation of interfacial resistances will enable the potential of high figure of merit materials to create thermoelectric energy conversion devices that are - - competitive with alternative technologies.
Keywords :
contact resistance; electrical conductivity; thermal conductivity; thermoelectric conversion; alternative heat removal; electrical conductivity; electrical contact resistances; electrical interfacial effects; energy harvesting devices; energy harvesting technologies; heat exchangers; low-dimensional scaling; on-chip integration; on-chip thermoelectric cooling; pellet-interconnect interfaces; semiconductor-metal interfaces; thermal conductivity; thermal contact resistances; thermal interfacial effects; thermoelectric energy conversion devices; thermoelectric pellet; Contacts; Energy conversion; Material properties; Quantum dots; Superlattices; Thermal conductivity; Thermal resistance; Thermoelectric devices; Thermoelectricity; Thin films;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Thermoelectrics, 2007. ICT 2007. 26th International Conference on
Conference_Location :
Jeju Island
ISSN :
1094-2734
Print_ISBN :
978-1-4244-2262-3
Electronic_ISBN :
1094-2734
Type :
conf
DOI :
10.1109/ICT.2007.4569480
Filename :
4569480
Link To Document :
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