TY - GEN
T1 - Optimization of thermoelectric efficiency in graded materials
AU - Dashevsky, Z.
AU - Gelbstein, Y.
AU - Edry, I.
AU - Drabkin, I.
AU - Dariel, M. P.
N1 - Publisher Copyright:
© 2003 IEEE.
PY - 2003/1/1
Y1 - 2003/1/1
N2 - In order to achieve high thermoelectric conversion efficiency, it is necessary to make use of materials with a maximal figure of merit Z = S2xσ/k (S is the Seebeck coefficient, σ and k are the electrical and thermal conductivity, respectively) over a wide temperature range. AIVBVI (chalcogenides of group IV elements) semiconductors are well known materials that have found widespread applications in thermoelectric energy converters. The thermoelectric properties of semiconductors may be improved by designing crystals with a gradient of charge carrier concentration that is commensurate with the temperature gradient that prevails along the axis in an actual thermoelectric device. Recently graded n-type PbTe-based single crystals doped with indium have been shown to display promising thermoelectric properties. The thermoelectric efficiency of graded materials is usually not a direct measurable quantity. It seemed of interest to develop a theoretical model that would allow deriving this property. The present communication is concerned with the development of a simulation model for estimating the characteristics of a thermoelectric leg and based on determining the temperature profile along its length. The temperature distribution along a leg was calculated from the heat flux equation under steady state conditions for the 50-500°C temperature range. In the calculation, account was taken of the temperature dependence of S, σ and k, respectively, for graded n-type PbTe crystals doped with indium. A comparison to iodine-doped homogeneous PbTe crystals is presented as well. These calculations allow determining the dopant concentration profile along the thermoelectric leg that provides optimal efficiency. The results suggest the possibility, in principle, of achieving conversion efficiency higher than 12% by using graded n-type PbTe crystals doped with indium in the 50-600°C temperature range.
AB - In order to achieve high thermoelectric conversion efficiency, it is necessary to make use of materials with a maximal figure of merit Z = S2xσ/k (S is the Seebeck coefficient, σ and k are the electrical and thermal conductivity, respectively) over a wide temperature range. AIVBVI (chalcogenides of group IV elements) semiconductors are well known materials that have found widespread applications in thermoelectric energy converters. The thermoelectric properties of semiconductors may be improved by designing crystals with a gradient of charge carrier concentration that is commensurate with the temperature gradient that prevails along the axis in an actual thermoelectric device. Recently graded n-type PbTe-based single crystals doped with indium have been shown to display promising thermoelectric properties. The thermoelectric efficiency of graded materials is usually not a direct measurable quantity. It seemed of interest to develop a theoretical model that would allow deriving this property. The present communication is concerned with the development of a simulation model for estimating the characteristics of a thermoelectric leg and based on determining the temperature profile along its length. The temperature distribution along a leg was calculated from the heat flux equation under steady state conditions for the 50-500°C temperature range. In the calculation, account was taken of the temperature dependence of S, σ and k, respectively, for graded n-type PbTe crystals doped with indium. A comparison to iodine-doped homogeneous PbTe crystals is presented as well. These calculations allow determining the dopant concentration profile along the thermoelectric leg that provides optimal efficiency. The results suggest the possibility, in principle, of achieving conversion efficiency higher than 12% by using graded n-type PbTe crystals doped with indium in the 50-600°C temperature range.
KW - Conducting materials
KW - Crystalline materials
KW - Crystals
KW - Indium
KW - Leg
KW - Semiconductor materials
KW - Temperature distribution
KW - Thermal conductivity
KW - Thermoelectric devices
KW - Thermoelectricity
UR - http://www.scopus.com/inward/record.url?scp=84946052807&partnerID=8YFLogxK
U2 - 10.1109/ICT.2003.1287538
DO - 10.1109/ICT.2003.1287538
M3 - Conference contribution
AN - SCOPUS:84946052807
T3 - International Conference on Thermoelectrics, ICT, Proceedings
SP - 421
EP - 424
BT - Proceedings ICT 2003 - 22nd International Conference on Thermoelectrics
PB - Institute of Electrical and Electronics Engineers
T2 - 22nd International Conference on Thermoelectrics, ICT 2003
Y2 - 17 August 2003 through 21 August 2003
ER -