Matching characteristics of different buffer layers with VO2 thin films

VO 2 thin films were fabricated by reactive DC magnetron sputtering on different buffer layers of MgF 2 , Al 2 O 3 and TiO 2 , respectively. The crystallinity and orientation relationship, thickness of VO 2 thin films, atoms vibrational modes, optical and electrical property, surface morphology of films were characterized by X-ray diffraction, Raman scattering microscopy, step profiler, spectrophotometer, four-probe technique, and scanning electron microscopy, respectively. XRD results investigated that the films have preferential crystalline planes VO 2 (011). The crystallinity of VO 2 films grown on TiO 2 buffer layers are superior to VO 2 directly deposited on soda-lime glass. The Raman bands of the VO 2 films correspond to an Ag symmetry mode of VO 2 (M). The sample prepared on 100nm TiO 2 buffer layer appears nanorods structure, and exhibits remarkable solar energy modulation ability as high as 5.82% in full spectrum and 23% in near infrared spectrum. Cross-sectional SEM image of the thin films samples indicate that MgF 2 buffer layer has clear interface with VO 2 layer. But there are serious interdiffusion phenomenons between Al 2 O 3 , TiO 2 buffer layer with VO 2 layer.