Ultrahigh Power Factor of Sputtered Nanocrystalline N-Type BiTe Thin Film via Vacancy Defect Modulation and Ti Additives.

Magnetron-sputtered thermoelectric thin films have the potential for reproducibility and scalability. However, lattice mismatch during sputtering can lead to increased defects in the epitaxial layer, which poses a significant challenge to improving their thermoelectric performance. In this work, nanocrystalline n-type BiTe thin films with an average grain size of ≈110 nm are prepared using high-temperature sputtering and post-annealing.