Preparation and optical properties of VO2/FTO thermochromic composite films

The pure metal thin films were fabricated on the F doped SnO2 conductive glass( FTO) substrates by DC magnetron sputtering at room temperature. Then the VO2/FTO composite films were annealed in furnace. The structure and optical properties of the composite films were analyzed by instruments. Results show that FTO on the glass does not change the preferred orientation growth of VO2 thin films, but significantly change its surface morphology characteristics. Compared with the VO2 thin films that were prepared on glass substrates with the same process conditions, the phase transition temperature of the VO2/FTO composite films is decreased about 18 degrees C, the width of thermal hysteresis is narrowed by about 4 degrees C, and the infrared transmittances before and after phase transition are 42% and 21% respectively. It suggested that the composite films can reduce the phase transition temperature, limit the thermal hysteresis loop as well as enhance the infrared light modulation capabilities of VO2 thin films.