Thermoelectric performances of thin films are affected by both the morphology and composition of the films. On one hand, the compact morphology of films could increase electrical conductivity via boosting carrier mobility. On the other hand, for semimetal or semiconductor materials, alloying is an effective means to adjust the carrier concentration and band structure and further modulate thermoelectric performances. In this work, with an in-situ high-vacuum annealing technique, we prepared compact Bi_1-xSb_x thin films via magnetron sputtering and further modulated their power factor by varying Sb content. Thermoelectric transport measurements revealed an enhanced room-temperature power factor up to 23.48 μW/(cmK²) in compact Bi_0.95Sb_0.05 film with high carrier mobility. Our simulation results based on a tight-binding model, in conjunction with the experimentally observed mobility peak, suggest that the observation of enhanced thermoelectric power factor is possibly related to the composition-induced band structure modulation.

薄膜的热电性能受薄膜的形貌和成分的影响。一方面，薄膜的紧凑形态可以通过提高载流子迁移率来提高电导率。另一方面，对于半金属或半导体材料，合金化是调节载流子浓度和能带结构，进一步调节热电性能的有效手段。在这项工作中，我们使用原位高真空退火技术，通过磁控溅射制备了致密的 Bi _1-x Sb _x薄膜，并通过改变 Sb 含量进一步调节其功率因数。热电传输测量显示，在紧凑型 Bi _0.95 Sb 中，室温功率因数提高到 23.48 μW/(cmK ² )_0.05薄膜，具有高载流子迁移率。我们基于紧束缚模型的模拟结果，结合实验观察到的迁移率峰，表明观察到的热电功率因数增强可能与成分诱导的能带结构调制有关。