• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.25-25
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• 2005

• Journal of the Microelectronics and Packaging Society
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• v.15 no.1
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• pp.1-6
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• 2008

Thermoelectric properties of calcium cobalt layer structure oxide system, $Ca_3Co_2O_6$ and $Ca_3Co_4O_9$ were investigated at the temperature range of 300 to 1000K for the application of thermoelectric generation. In the composition, the Ca site was partially substituted with Bi, Sr, La, K and the Co site was partially substituted with Mn, Fe, Ni, Cu, Zn. The thermoelectric properties of Bi substituted $Ca_3Co_4O_9$. $Ca_{2.7}Bi_{0.3}Co_4O_9$ for electrical conductivity, Seebeck coefficient and power factor were $85.4({\Omega}$cm)^{-l}, $176.2{\mu}V/K$ and $265.2{\mu}W/K^m$, respectively. The unit thermoelectric couple was fabricated with the p-type of $Ca_{2.7}Bi_{0.3}Co_4O_9$ and n-type ($Zn_{0.98}Al_{0.02}$)O thermoelectrics whose figure-of-merit(Z) were $0.87{\times}10^{-4}/K$ and $0.41{\times}10^4/K$, respectively. The generated thermoelectric power was about 30mV at the temperature difference of 120K in the unit thermoelectric couple.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.4
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• pp.93-100
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• 2008

The one and two pair of oxide modules for high temperature thermoelectric power generation were fabricated with $Ca_{2.7}Bi_{0.3}Co_4O_9$(p-type) and $Ca_{0.96}Bi_{0.04}Mn_{0.96}Nb_{0.04}O_3$(n-type) on $Al_2O_3$ substrate. For the optimizing of the design process, contact resistance was derived from the results of the one pair modules, and then the resistance of two pair modules were calculated to use the derived data. Those values were compared with the measured values for the optimizing of this design process. The resistance of calculated and measured two pairs modules was 0.956 $\Omega$ and 1.110 Q $\Omega$ $T_h$=833 K, respectively, the difference of resistance was about 0.15 $\Omega$. From the result, proposed design process is effective for high temperature thermoelectric oxide modules fabrication.

• Ceramist
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• v.22 no.2
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• pp.133-145
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• 2019

Thermoelectric energy conversion has attracted much attention because it can convert heat into electric power directly through solid state device and vice versa. Current research is aimed at increasing the thermoelectric figure of merit (ZT ) by improving the power factor and reducing the thermal conductivity. Although there have been significant progresses in increasing ZT of material systems composed of Bi, Te, Ge, Pb, and etc. over the last few decades, their relatively high cost, toxicity, and the scarcity have hindered further development of thermoelectrics to expand practical applications. In this paper, we review the current status of research in the fields of nanostructured thermoelectric materials with eco-friendly and low cost elements, such as skutterudites and oxides, for mid-high temperature applications, highlighting the strategies to improve thermoelectric performance.