Elemental doping is essential for tuning thermoelectric properties. However, effective doping has been a challenging task particularly for low dimensional materials. Here we demonstrate a vacancy-engineering strategy for effective doping to enhance thermoelectric properties of two-dimensional (2D) materials, using van der Waals tellurium as an example. Both Density Functional Theory (DFT) calculations and temperature dependent thermoelectric measurements confirm that annealing-induced vacancies can effectively shift the Fermi level into the valance band of individual 2D tellurium nanosheets, and consequentially increase the electrical conductivity significantly from 7 × 10³ Sm⁻¹ to 2.7 × 10⁴ Sm⁻¹. As a result, this vacancy-engineering induced self-doping effect yields a state of art thermoelectric figure-of-merit (ZT) of 0.4 at 400 K. Therefore, our work provides an alternative and promising pathway for tuning the thermoelectric properties desirable for low dimensional materials.

元素掺杂对于调节热电性能至关重要。但是，有效掺杂一直是一项挑战性的任务，特别是对于低尺寸材料而言。在这里，我们以范德华（Van der Waals）碲为例，演示了一种有效掺杂以提高二维（2D）材料热电性能的空位工程策略。密度泛函理论（DFT）计算和与温度相关的热电测量均证实，退火引起的空位可以有效地将费米能级转移到单个2D碲纳米片的价带中，从而将电导率从7×10 ³ Sm ^-1显着提高至2.7×10 ⁴ Sm ^-1。结果，这种由空位工程引起的自掺杂效应在400 K时可产生0.4的最新热电品质因数（ZT）。因此，我们的工作提供了一种可替代的有希望的途径来调节所需的热电性能低尺寸材料。