We report optical, structural, and electrical properties of VO2 on sapphire substrates with c-, m-and r- orientations with identical growth conditions. XRD data show that VO2 orientation depends on the substrate orientation. Based on temperature-dependent resistivity measurements, metal-insulator phase transition (MIT) temperature, TMIT, depends on the VO2 orientation due, primarily, to stress. The energy gap Eg is observed to gradually red shift as temperature increases before collapsing to Eg ≈ 0 eV at temperatures below TMIT.
- And refractive index
- Energy gap
- Metal-insulator phase transition (MIT)
- Spectroscopic ellipsometry