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| Type |
Poster Presentation |
| Area |
Material Chemistry |
| Room No. |
Event Hall |
| Time |
4월 20일 (금요일) 11:00~12:30 |
| Code |
MAT.P-492 |
| Subject |
A new family of n-type Bi2Te3-based thermoelectric materials unusually driven by divalent alkali earth metal doping |
| Authors |
Sejin Byun, CHUNG IN1,*
Chemical and biological engineering, Seoul National University, Korea
1Division of Chemical & Biological Engineering, Seoul National University, Korea
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| Abstract |
Thermoelectric technology enables direct and reversible conversion between heat and electricity, thereby a promising means of sustainable power generation via waste heat harvesting. Bi2Te3-based thermoelectric materials are commercially available and the most efficient system operating near room temperature. However, it is difficult to stabilize their n-type materials with high conversion efficiency because few effective dopants and substituents on these systems have been developed. To address this important issue, we discuss our synthesis of a new family of the n-type Bi2Te3-based system by doping alkali earth metals (AE = Mg, Ca, Sr, Ba), namely, AExBi2-xTe3 (0≤x≤0.02) and the unusual n-type doping effect of alkali earth metal Bi2Te3. AE doping markedly enhances carrier concentrations and electrical conductivities without significantly sacrificing Seebeck coefficients, resultantly improving power factors. It also simultaneously reduces thermal conductivities due to point defect scattering of heat-carrying phonon. Optimizing the carrier concentration via AE doping boosts thermoelectric figure of merit (ZT) to ~0.8 at 350K for Mg0.01Bi1.99Te3 from ~0.4 for pristine Bi2Te3 at the same temperature. |
| E-mail |
bsjin1992@snu.ac.kr |
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121st General Meeting of the KCS