Development of thermoelectrics usually involves trial-and-error investigations, including time-consuming synthesis and measurements. Here, we identify the electronic quality factor B_E for determining the maximum thermoelectric power factor, which can be conveniently estimated by a single measurement of Seebeck coefficient and electrical conductivity of only one sample, not necessarily optimized, at an arbitrary temperature. We demonstrate that thousands of experimental measurements in dozens of materials can all be described by a universal curve and a single material parameter B_E for each class of materials. Furthermore, any deviation in B_E with temperature or doping indicated new effects such as band convergence or additional scattering. This makes B_E a powerful tool for evaluating and guiding the development of thermoelectrics. We demonstrate the power of B_E to show both p-type GeTe alloys and n-type Mg₃SbBi alloys as highly competitive materials, at near room temperature, to state-of-the-art Bi₂Te₃ alloys used in nearly all commercial applications.

热电学的发展通常涉及反复试验的研究，包括耗时的综合和测量。在这里，我们确定了用于确定最大热电功率因数的电子品质因数B _E，可以通过在任意温度下仅测量一个塞伯克系数和电导率的单个测量（不必优化）来方便地估算出该值。我们证明，对于每种材料，可以通过通用曲线和单个材料参数B _E来描述数十种材料中的数千个实验测量值。此外，B _E的任何偏差温度或掺杂表明有新的效应，例如能带收敛或附加散射。这使B _E成为评估和指导热电发展的有力工具。我们证明了B _E能够在接近室温的情况下展示p型GeTe合金和n型Mg ₃ SbBi合金是具有高度竞争力的材料，与几乎所有领域中使用的最新Bi ₂ Te ₃合金一样商业应用。