Improved thermoelectric properties of AgSbTe2 based compounds with nanoscale Ag2Te in situ precipitates
Improved thermoelectric properties of AgSbTe2 based compounds with nanoscale Ag2Te in situ precipitates
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DOI：
10.1016/j.jallcom.2010.03.170
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发表时间：
2010-06
影响因子：
6.2
通讯作者：
Suzhan Zhang;T. Zhu;S. H. Yang;Chengbo Yu;X. Zhao
中科院分区：
文献类型：
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作者：
Suzhan Zhang;T. Zhu;S. H. Yang;Chengbo Yu;X. Zhao
制备了AgxSb_2、−_xTe_3、−_x三元热电材料，x值在0.78~0.93之间变化。当x&gT；为0.81时，通过调节Ag2Te的比例，将纳米结构的Ag2Te嵌入到AgSbTe2中，得到了双相原位纳米复合材料。高分辨电子显微镜观察表明，Ag2Te析出物为纳米点状和纳米片层结构。与x=0.78和0.81的单相样品相比，纳米复合样品的Seebeck系数在整个测量温度范围内都有显著提高，电导率也略有增加，导致功率因数增加。同时，纳米复合样品的导热系数略有下降。通过对功率因数和导热系数的优化，使670K时的优值系数ZT显著提高了∼40%。
Ternary AgxSb2−xTe3−xthermoelectric materials have been prepared with x value varying from 0.78 to 0.93. By adjusting the Ag2Te ratio, double-phased in situ nanocomposites were obtained with the nanostructured Ag2Te embedded in the AgSbTe2matrix when x>0.81. The high-resolution transmission electron microscopy observation showed that the Ag2Te precipitates were in situ formed as nanodots and nanoscale lamellar structures. Compared with the single-phased samples of x=0.78 and 0.81, the Seebeck coefficient of the nanocomposite samples exhibited significant improvement over the entire measured temperature range and the electrical conductivity also slightly increased, resulting in the increase of the power factor. At the same time, the thermal conductivity of the nanocomposite samples slightly decreased. The optimization of both the power factor and the thermal conductivity contributed to the notable improvement in figure of merit ZT by a factor of ∼40% at 670K.