Thermoelectric properties of p-type Ag_{1−le='font-style: italic'>x}(Pb_{1−le='font-style: italic'>y}Sn_y)_mSb_{1−le='font-style: italic'>z}Te_m+2

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• 作者：Kyunghan Ahn^a ; ^c ; Huijun Kong^b ; Ctirad Uher^b ; Mercouri G. Kanatzidis^a ; ^{m-kanatzidis@northwestern.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Thermoelectricity ; Chalcogenides
• 刊名：Journal of Solid State Chemistry
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：242
• 期：part_P2
• 页码：34-42
• 全文大小：3365 K

文摘

The thermoelectric properties of Ag_1−x(Pb_1−ySn_y)_mSb_1−zTe_m+2 (4&le;m&le;16, −0.1&le;x&le;0.3, 1/3&le;y&le;2/3, 0.2&le;z&le;0.4; Lead Antimony Silver Tellurium Tin, LASTT-m) compositions were investigated in the temperature range of 300 to ~670 K. All samples crystallize in the average NaCl-type structure without any noticeable second phase and exhibit very narrow bandgaps of <0.1 eV. We studied a range of m values, silver concentrations (x), Pb/Sn ratios (y), and antimony concentrations (z) to determine their effects on the thermoelectric properties. The samples were investigated as melt grown polycrystalline ingots. Varying the Ag contents, the Pb/Sn ratios, and the Sb contents off-stoichiometry allowed us to control the electrical conductivity, the Seebeck coefficient, and the thermal conductivity. The electrical conductivity tends to decrease with decreasing m values. The highest ZT of ~1.1 was achieved at ~660 K for Ag_0.9Pb₅Sn₅Sb_0.8Te₁₂ mainly due to the very low lattice thermal conductivity of ~0.4 W/(m K) around 660 K. Also, samples with charge-balanced stoichiometries, Ag(Pb_1−ySn_y)_mSbTe_m+2, were studied and found to exhibit a lower power factor and higher lattice thermal conductivity than the Ag_1−x(Pb_1−ySn_y)_mSb_1−zTe_m+2 compositions.