Refractory rare-earth tellurides with the Th₃P₄ structure type have attracted considerable interest as high-performance thermoelectric materials since the 1980s due to their high dimensionless figure of merit (ZT). Extensive work has been conducted on La_3−xTe₄ with peak ZT values greater than 1.1 at 1,273 K. The high ZT of La_3-xTe₄ is in part due to a large peak in the density of states near the Fermi level from the La 5d states. Here, we revisit Pr_3−xTe₄, for which our electronic structure calculations predict a favorable modification of the density of states by the introduction of praseodymium's 4f electrons. This was experimentally verified by preparing Pr_3−xTe₄ samples with varying Pr vacancy concentrations using a mechanochemical synthesis approach. The thermoelectric properties were measured and a ZT of 1.7 at 1,200 K was achieved with Pr_2.74Te₄. The 50% improvement in peak ZT compared with La_3−xTe₄ resulted from an increased effective mass, improved Seebeck coefficient, and lower thermal conductivity.

自1980年代以来，具有Th ₃ P ₄结构类型的难熔稀土碲化物因其无量纲的高品质因数（ZT）而作为高性能热电材料引起了人们的极大兴趣。大量工作已有关La已经进行_{3- X}碲₄与峰ZT在1273 K的高值大于1.1的ZT的La _{3- X}碲₄是部分地由于在状态的费米能级附近的密度大的峰值来自La 5d州。在这里，我们重新审视Pr _{3− x} Te ₄，我们的电子结构计算通过predict 4f电子的引入预测了态密度的有利变化。通过使用机械化学合成方法制备具有不同Pr空位浓度的Pr _{3- x} Te ₄样品，通过实验验证了这一点。测量了热电性能，并用Pr _2.74 Te ₄在1200 K下实现了1.7的ZT。与La _{3- x} Te ₄相比，ZT峰值提高了50％，这是由于有效质量增加，塞贝克系数提高和热导率降低所致。