Broadband temperature-dependent dielectric properties of polycrystalline vanadium dioxide thin films

Broadband dielectric properties of VO₂ polycrystalline thin films deposited on fused quartz substrate by reactive pulsed laser deposition are measured and characterized at GHz frequencies. The relative dielectric constant is extracted using the platform of coplanar waveguide via a multi-line TRL method, combined with either a conformal mapping model or a full-wave calculation process. It is found in this work that increasing the temperature of the studied VO₂ thin film over its transition temperature results in a dramatic increase of both relative permittivity and conductivity by more than 3 orders of magnitude.