Process-Induced Chemical Reactions on Interfaces of Thin Film Ionic Materials

This dataset supports a study of process-induced interfacial reactions — specifically, spontaneous lithium transfer (autolithiation) — occurring during magnetron sputter deposition of thin dielectric lithium-containing films (lithium phosphorus oxynitride, LiPON, and lithium oxide, Li₂O) onto vanadium pentoxide (V₂O₅) underlayers. Ten sample configurations were fabricated on a single silicon wafer substrate using an in-situ mask exchanger-equipped sputtering system, with overlayer thicknesses of 10 and 20 nm and either room-temperature or 300 °C post-annealing conditions. The dataset includes raw electrochemical, spectroscopic, and optical measurements used to characterize the compositional, structural, optical, and electrical properties of the V₂O₅ underlayers and LiPON/Li₂O overlayers as a function of deposition conditions. These measurements demonstrate that autolithiation proceeds concurrently with overlayer film growth and is governed by thermodynamic decomposition at the film interface. LiPON forms stable, electron-blocking overlayers as thin as 15 nm while lithiating the V₂O₅ at rates of approximately 1 μA/cm², whereas Li₂O deposition results in near-complete lithium transfer into the V₂O₅, achieving compositions approaching Li₃V₂O₅ with less than 2 nm of residual overlayer. The findings have direct implications for the rational design of thin-film fabrication sequences for energy storage, electrochemical random-access memory (ECRAM), and neuromorphic devices.