Conformal ultra-thin, ultra-uniform metal films fabricated on non-planar substrates for advanced optoelectronics

Abstract Transparent conducting films are indispensable to modern optoelectronic devices due to their unique combination of high transparency and electrical conductivity. While existing fabrication methods—such as physical vapor deposition and solution-based synthesis—are well-established for flat substrates, producing high-quality transparent conductors on non-planar surfaces remains a significant challenge, largely due to difficulties in achieving conformal coverage, nanoscale uniformity, and consistent optoelectrical performance. In this study, we report a conformal deposition model with metal co-doping method on curved surfaces that can produce ultra-thin (≤10 nm), ultra-uniform (±0.5 nm), and ultra-smooth metal films. This work sets a new benchmark for conformal sub-10 nm metal films, whose optoelectrical performance rivals that of planar counterparts, achieving an average visible transmittance of ∼88% and sheet resistance of ∼8.1 Ω·sq ⁻¹ with capping layers. In addition, the process can be further extended to a range of optical dielectrics, enabling precise production of advanced conformal coatings. These findings provide practical pathways for optoelectronic applications, including curved transparent electrodes, three-dimensional optical-to-microwave devices, and next-generation smart glasses.