Two strategies were proposed to optimize the thermoelectric performance of BaMg₂(Bi,Sb) through a solid solution method and to tune the crystal field splitting energy of orbital by using first principles calculation and Boltzmann transport theory. The increase in Sb content leads to decreased weight carrier mobility due to the changes in the electronic structure. The lattice thermal conductivity for BaMg₂SbBi can be as low as 0.45 W m⁻¹K⁻¹, which is lower than those of other compounds. The highest ZT of ∼0.88 for BaMg₂SbBi has been obtained at 750 K with n-type doping carrier concentration of −8.28 10¹⁸ cm⁻³, indicating that reaching the optimal Sb content (i.e. BaMg₂SbBi) can make a significant contribution to the maximization of the ZT of n-type BaMg₂(Bi,Sb) solid solutions. Adjusting the crystal field splitting energy increases the effective mass of density of states, which causes the change in power factor (PF) value and achieves a maximum PF value. When the tensile strain for BaMg₂Bi₂, BaMg₂SbBi, and BaMg₂Sb₂ is 2%, 2%, and 6%, the ZT value is significantly improved, respectively. Therefore, minimizing crystal field splitting energy is also effective in the optimization of the ZT value.

提出了两种策略，通过固溶法优化 BaMg ₂ (Bi,Sb)的热电性能，并通过第一性原理计算和玻尔兹曼输运理论调整轨道的晶体场分裂能。由于电子结构的变化，Sb 含量的增加导致重量载流子迁移率降低。BaMg ₂ SbBi的晶格热导率可低至0.45 W m ^-1 K ^-1，低于其他化合物的晶格热导率。BaMg ₂ SbBi的最高 ZT 约为 0.88，在 750 K 下获得，n 型掺杂载流子浓度为 -8.28 10 ¹⁸ cm ^-3，表明达到最佳 Sb 含量（即 BaMg ₂ SbBi）可以对最大化 n 型 BaMg ₂ (Bi,Sb) 固溶体的 ZT 做出重要贡献。调整晶体场分裂能量会增加态密度的有效质量，从而引起功率因数（PF）值的变化并达到最大PF值。当BaMg ₂ Bi ₂、BaMg ₂ SbBi 和BaMg ₂ Sb ₂的拉伸应变分别为2%、2%和6%时，ZT值分别显着提高。因此，最小化晶体场分裂能量对于优化 ZT 值也是有效的。