Mid‐IR Ellipsometric Characterization of Eicosane Layers on VO 2 ‐Based Surfaces

This work presents a materials‐and‐methods study of vanadium dioxide/p‐type silicon (VO 2 /Si(p)) substrates for the mid‐infrared spectroscopic ellipsometry (MIR‐SE) characterization of deposited eicosane layers, complemented by a preliminary Raman assessment. We assess the optical response of VO 2 ‐based surfaces after drop‐coating with eicosane‐based solution. Mid‐infrared ellipsometric measurements identify characteristic vibrational fingerprints associated with the alkane, providing information on changes in the optical response of the VO 2 /eicosane interface. Temperature‐dependent reflectance measurements were used to characterize the thermochromic behavior of the substrates, providing complementary information on their functional optical properties and supporting interpretation of the MIR response. As a qualitative proof‐of‐concept, preliminary surface‐assisted Raman measurements on a titanium dioxide (TiO 2 )‐containing VO 2 substrate (nominal 4%) revealed weak spectral features attributable to eicosane, providing qualitative support via an independent spectroscopic pathway. Overall, these results demonstrate the feasibility of VO 2 ‐based platforms for label‐free MIR analysis of long‐chain hydrocarbons, supporting their further investigation in complex lipid matrices potentially relevant to Parkinson’s disease research.