The effect of TiO2 buffer layer thickness on the thermochromic properties of VO2 thin-film fabricated by high density plasma source

Abstract

Thermochromic VO2 thin films are fabricated by using high power impulse magnetron sputtering at room temperature. In order to increase the crystallinity and transparency of VO2 thin films, a barrier layer of TiO2 is deposited on the glass substrate. Then TiO2/VO2 stacks are post-annealed at a temperature of 500 °C for 3 min. The transmittance properties as functions of TiO2 and VO2 thicknesses are discussed. The effects of TiO2 thickness on the strain state of (011) and () planes of monoclinic phase are studied. The laminated film shows satisfactory optical properties with an excellent solar regulation efficiency (ΔTsol = 10.2%) and an acceptable luminous transmittance (Tlum = 41.1%) in a low-temperature state. Good endurance property is demonstrated using a thermal stress cycle of 25 °C/85 °C for 100 times.