State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.
Nanotechnology. 2008 Jun 18;19(24):245707. doi: 10.1088/0957-4484/19/24/245707. Epub 2008 May 12.
The thermoelectric properties of (GeTe)(x)(AgSbTe(2))(100-x) compounds (x = 75, 80, 85 and 90; TAGS-x) have been studied as a function of temperature from 300 to 720 K. At 720 K the dimensionless figure of merit ZT reaches the state-of-the-art value of 1.53 for TAGS-75 and 1.50 for TAGS-80 and TAGS-85 samples, respectively. But the ZT value of the TAGS-90 sample is only 0.50 at 720 K due to the high carrier concentration. Utilizing high-resolution transmission electron microscope and selected area electron diffraction techniques, we identify a considerable number of nanoscale domains with typical size ∼10 nm in the samples that show high ZT values. It is suggested that the presence of nanoscale domains, like the situation in PbTe-AgSbTe(2) compounds, should make a slight contribution to the low lattice thermal conductivity of TAGS compounds due to the enhanced mid-frequency phonon scattering.
（GeTe）（x）（AgSbTe2）（100-x）化合物（x = 75、80、85 和 90；TAGS-x）的热电性能已作为温度的函数从 300 至 720 K 进行了研究。在 720 K，无量纲品质因数 ZT 分别达到了 TAGS-75 为 1.53，TAGS-80 和 TAGS-85 为 1.50 的最新值。但是由于载流子浓度较高，TAGS-90 样品在 720 K 时的 ZT 值仅为 0.50。利用高分辨率透射电子显微镜和选区电子衍射技术，我们在显示高 ZT 值的样品中识别出相当数量的典型尺寸约为 10nm 的纳米级畴。有人认为，纳米级畴的存在，就像 PbTe-AgSbTe2 化合物中的情况一样，由于中频声子散射增强，应该对 TAGS 化合物的低晶格热导率有轻微的贡献。
