SnO2/VO2/SnO2 tri-layer thermochromic films with high luminous transmittance, remarkable solar modulation ability and excellent hydrophobicity grown on glass substrates

The SnO2/VO2/SnO2 (SVS) multilayer films were prepared using pulsed laser deposition and were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, Hall Effect Measurement System, double beam spectrophotometer and contact angle measurements. The results showed that SVS multilayer films with excellent thermochromic properties were obtained by adjusting the preparation temperature of the SnO2 buffer layer and antireflection layer. When the preparation temperature of the SnO2 layer was 320 °C, the phase transition amplitude (ΔR) of the VO2 film reached 354 times and both the phase transition temperature (Tc) and hysteresis loop width (ΔH) could be effectively reduced. Meanwhile, the SVS multilayer film had satisfactory luminous transmittance (50.2%) and solar modulation ability (15.3%), achieving the balance of optical properties. In addition, all the SVS multilayer films exhibited excellent hydrophobicity. Boiling water experiments show that the service life of SVS tri-layer film is twice that of SV bi-layer film. This work suggests that the SVS multilayer films are a good candidate for VO2-based smart windows.