Thermoelectric properties of CuIn1-xGaxTe2 single crystals
Thermoelectric properties of CuIn1-xGaxTe2 single crystals
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DOI：
10.1002/1521-396x(199708)162:2
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发表时间：
1997-08
期刊：
影响因子：
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通讯作者：
B. Kuhn;W. Kaefer;K. Fess;K. Friemelt;C. Turner;M. Wendl;E. Bucher
中科院分区：
文献类型：
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作者：
B. Kuhn;W. Kaefer;K. Fess;K. Friemelt;C. Turner;M. Wendl;E. Bucher
本文报道了CuGaTe 2、CuInTe 2及其固溶体CuIn 1-xGaxTe 2的晶体生长和电学特性。通过区域熔化和垂直布里奇曼技术获得单晶。从电阻率和霍尔效应测量的温度范围为35至400 K的载流子浓度和迁移率进行了测定。所有样品均显示p型导电性。室温下的空穴密度约为p = 1020 cm-3，表明这些材料是简并半导体.对于热电应用，需要弱简并半导体。为了研究这些材料是否适用于热电应用，我们测量了90至400 K之间的塞贝克系数和80至360 K范围内的热导率。从所获得的数据的分析，我们能够计算的费米能级的温度依赖性，态密度的空穴的有效质量，电子的热导率和热电材料的品质因数的贡献。理论估计表明，存在一个最佳掺杂浓度，导致该材料组的最大品质因数Z。进一步的可能性，以提高Z进行了讨论。
In this paper we report on crystal growth an the electrical characterization of the compounds CuGaTe 2 , CuInTe 2 and their solid solutions CuIn 1-x Ga x Te 2 . Single crystals were obtained by zone melting and a vertical Bridgman technique. From resistivity and Hall effect measurements in the temperature range of 35 to 400 K the carrier concentrations and mobilities were determined. All samples showed p-type conductivity. The hole densities at room temperature were approximately p = 10 20 cm -3 , which indicates that these materials are degenerate semiconductors. For thermoelectric applications weakly degenerate semiconductors are required. In order to investigate whether these materials are suitable for thermoelectric applications we measured the Seebeck coefficient between 90 and 400 K and the thermal conductivity in the range of 80 to 360 K. From the analysis of the obtained data we were able to calculate the temperature dependence of the Fermi level, the density-of-states effective mass of holes, the electronic contribution to the thermal conductivity and the figure of merit for a thermoelectric material. With a theoretical estimation it is shown that there is a optimum doping concentration which leads to a maximum figure of merit Z for this material group. Further possibilities to improve Z are discussed.