ABSTRACT We have studied the doping concentration dependence of the thermoelectric (TE) properties for the n- and p-doped CaIn2P2 layered Zintl phase at two fixed temperatures: T = 600 and 900 K through first-principles electronic band structure calculations combined with Boltzmann's transport theory within charge-carrier relaxation time and rigid band approximations. The band structure calculated using the Tran-Blaha modified Becke–Johnson potential shows a fundamental indirect energy band gap (E g) of 1.10 eV that comes from the polyanion (In2P2)−2. CaIn2P2 exhibit a mixture of flat and dispersive energy bands in the energy window from to eV, which is a required characteristic for high electrical transport coefficients. The computed lattice thermal conductivity for CaIn2P2 is equal to at 900 K and at 1250 K. This relatively low lattice thermal conductivity of CaIn2P2 can be mainly attributed to its layered crystalline structure. The highest value of the figure of merit of CaIn2P2, viz. ZT = 0.73 (0.71), is obtained for an optimal electron (hole) concentration of ( ) at 900 K.

中文翻译：

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层状 Zintl 相 CaIn2P2 的电子和热电特性：第一性原理计算

摘要 我们通过第一性原理电子能带结构计算结合玻尔兹曼输运，研究了 n 和 p 掺杂 CaIn2P2 层状 Zintl 相在两个固定温度下的热电 (TE) 特性的掺杂浓度依赖性：T = 600 和 900 K载流子弛豫时间和刚带近似中的理论。使用 Tran-Blaha 修正的 Becke-Johnson 势计算的能带结构显示来自聚阴离子 (In2P2)-2 的基本间接带隙 (E g) 为 1.10 eV。CaIn2P2 在从到 eV 的能量窗口中表现出平坦和色散能带的混合，这是高电传输系数所需的特性。CaIn2P2 的计算晶格热导率等于 900 K 和 1250 K。CaIn2P2 这种相对较低的晶格热导率主要归因于其层状晶体结构。CaIn2P2 的品质因数的最高值，即。ZT = 0.73 (0.71)，是在 900 K 时 ( ) 的最佳电子（空穴）浓度获得的。