Modulating Room Temperature Mid-IR Properties in W-Doped VO2 Films

Significant advances in mid-infrared optical technology depend on the development of innovative materials blending the properties of metals and insulators. In our work, we have systematically explored the thermochromic phase transition of vanadium dioxide. By introducing tungsten doping at room temperature through pulsed laser deposition technique onto sapphire substrates, we were able to precisely tailor the material's infrared optical responses. Our control over the tungsten concentration enabled us to finely tune both the amplitude and frequency of optical phonon resonances, as well as the free-electron response.