As a promising thermoelectric material at the medium temperature range, PbTe has attracted much attention during the past several decades. In this study, Ga-doped PbTe single crystals were synthesized by a facile Pb-flux method. The electronic structure calculations reveal that Ga substitution can introduce impurity level in the bandgap, which can effectively modulate the carrier concentration and therefore optimize the electrical conductivity. Experimentally, the carrier concentration was modulated from 1.95 to 4.46 × 10¹⁹ cm⁻³ at 300 K. Accordingly, the electrical conductivity reaches a maximum of 1.5 × 10⁵ S·m⁻¹ at 300 K for the sample with x = 0.025. As a result, maximal thermoelectric power factor 3.07 × 10⁻³ W·m⁻¹·K⁻² is attained at 360 K for the aforementioned sample, 62% higher than that of the undoped sample (1.89 ×10⁻³ W·m⁻¹·K⁻²). This work provides a viable method to synthetize high-quality single crystal and it also verifies that Ga substitution can significantly improve the electrical transport properties of single crystalline PbTe thermoelectric material.

作为一种在中温范围内很有前途的热电材料，PbTe 在过去的几十年中备受关注。在这项研究中，Ga 掺杂的 PbTe 单晶是通过一种简便的 Pb-flux 方法合成的。电子结构计算表明，Ga替代可以在带隙中引入杂质能级，可以有效调节载流子浓度，从而优化电导率。实验上，载流子浓度在 300 K 时从 1.95 调制到 4.46 × 10 ¹⁹ cm ^{-3 。因此，对于具有}x的样品，电导率在 300 K 时达到最大值 1.5 × 10 ⁵ S·m ^-1 = 0.025。结果，上述样品的最大热电功率因数为3.07×10 ^-3 W·m ^-1 ·K ^-2，比未掺杂样品的1.89×10 ^-3 W·m高62%。 ^-1 ·K ^-2 )。该工作为合成高质量单晶提供了可行的方法，也验证了Ga替代可以显着提高单晶PbTe热电材料的电传输性能。