Fabrication and optical-electrical properties of VO2/AZO composite films

Vanadium dioxide (VO2) thin film have been fabricated on the ZnO-doped Al conductive glass (AZO) substrates by DC magnetron sputtering and after thermal annealing. Effect of different annealing temperature and time olunation on the VO2/AZO composite films has been studied, then the structure, components and optical-electrical properties of the composite films are tested and analyzed by suitable instruments. Results show that the AZO film deposited on the conductive glass substrate dose not change the preferred orientation growth of the VO2 thin film, but its surface morphology characteristics are changed. Compared with those fabricated on ordinary glass substrates by the same processes and conditions, the phase transition temperature of the VO2/AZO composite film is decreased by about 25 ℃, and the width of thermal hysteresis is narrowed to about 6 ℃. Before and after phase transition, the visible light transmittance remains higher than 50%, and the infrared transmittances at a wavelength of 1500nm are 55% and 21% respectively. Furthermore, the resistivity rangeability is also up to three orders of magnitude before and after phase transition. In conclusion, the VO2/AZO composite films are easy to be fabricated and have a high degree of stability, smooth ness and compact surface morphology, thus they may be used to make new photoelectric devices