Advances in Thermoelectric Thin Films Grown by Atomic Layer Deposition: A Critical Review of Performance and Challenges

ABSTRACT This review critically examines recent progress in thermoelectric thin films synthesized by atomic layer deposition (ALD), with emphasis on their transport properties, growth strategies, and challenges. Chalcogenide thin films are discussed as the most direct analogs of conventional bulk thermoelectric materials, where ALD enables precise tuning of thickness, crystallinity, and carrier concentration, allowing comparative evaluation against conventional thin film deposition methods. Doped oxides and ternary oxides, particularly ZnO‐based systems with Al, Ga, or transition‐metal dopants, are highlighted as another important class, combining high‐temperature stability with tunable electronic transport, albeit with lower power factors than chalcogenides. Recent advances in molecular layer deposition have allowed the implementation of ALD/MLD multilayers and superlattices, showing how interface engineering and nanoscale modulation of potential barriers can influence carrier scattering and phonon transport. In parallel, we review precursor chemistry, deposition temperature windows, and process limitations, including environmental and safety considerations, to provide practical guidance for reproducibility and scalability. A comparative analysis with results from other deposition methods underlines that while ALD does not intrinsically outperform other deposition techniques, it offers complementary advantages in conformality and sub‐nanometer composition control, making it a powerful option for complex device architectures. Altogether, the review situates ALD‐grown thin films within the broader thermoelectric landscape, highlighting both their potential and the critical bottlenecks that remain.