| Summary: | 碩士 === 國立中山大學 === 材料與光電科學學系研究所 === 106 === In cope with the environmental protection and energy sustainability, the development of thermoelectric (TE) materials and devices has grown enormously in the recent decade. The p-type β-Zn4Sb3 attracts great attention in the application of mid-temperature TE generator, due to the fact that the β-Zn4Sb3 comprises the cost-effective, non-toxic and earth-abundant elements. The indium acts as effective dopant and substituted in β-Zn4Sb3, and the TE transport properties of In-doped Zn4Sb3 are evaluated systematically, with respect to the varying In ratios and the effects of different secondary phases. The solubility range of In in Zn4Sb3 is about 4%and the phase stability are further understood by the construction of isothermal section and liquidus projection of ternary In-Zn-Sb system, by collecting the phase equilibrium information/solidification sequence from the thermally-equilibrated/quenched alloys, respectively.
The thermoelectric properties of In-added alloys reveals decreasing thermal conductivity and increasing Seebeck coefficient were observed in the alloy (Zn0.95In0.05)4Sb3,which exhibiting the best phase stability and highest zT value reaches ~1.85 at 425℃(698K), showing 140% enhancement compared with the pure Zn4Sb3 (~1.3). And the alloy (Zn4Sb3)0.99(InSb)0.01 from the BEI can find there is the second phase Zn, which resulting has low thermal conductivity and higher Seebeck coefficient and exhibiting the high zT value reaches 1.82 at 400℃(673K), showing 182% enhancement compared with the pure Zn4Sb3(~1.0).
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