CuInTe_2的电子结构、晶格振动及热电性质

Electronic Structure, Lattice Vibration and Thermoelectric Properties of CuInTe_2

使用第一性原理研究了黄铜矿型CuInTe_2材料的电子结构、晶格动力学和热电输运性质。从电子结构分析可知,价带顶由3条重带组成,空穴有效质量较大,表明CuInTe_2有望成为潜在的p型热电材料。Cu、Te原子在价带顶有效杂化,成为主要的电输运通道。晶格动力学研究表明可以在Cu、In或Te原子位置引入结构缺陷,增加低频区域声子散射降低晶格热导率。不同温度、载流子浓度下的热电输运性质表明,在900 K、载流子浓度为4.7×10^(19)cm^(–3)时,p型CuInTe_2的热电优值达到1.6,是一种极具发展潜力的高温热电材料。

The electronic structure, lattice vibration and thermoelectric transport properties of CuInTe2 were investigated by the first-principles calculations. It is indicated that CuInTe2 can be used as a potential p-type thermoelectric material since the valence band maximum（VBM） is contributed by three heavy bands, which favors the promotion of the effective mass of hole. Cu and Te atoms are effectively hybridized at VBM, which form a conducting pathway for charge carriers. Based on the analysis of lattice dynamics, the thermal conductivity of CuInTe2 can be reduced by introducing the structural defects at Cu, In and Te sites to increase the scatter of phonon. The carrier concentration dependence of thermoelectric transport properties of p-type CuInTe2 at different temperatures was investigated. The results show that p-type CuInTe2 can obtain the figure of merit value of 1.6 at 900 K and 4.7×10^19cm^–3 carrier concentration, indicating that p-type CuInTe2 is a promising thermoelectric material at high temperatures.