Tuning thermochromic performance of VOx-based multilayer films by controlling annealing pressure

摘要

In this work, the nominal SiNx/NiCr/NiCrOx/VOx/NiCrOx/NiCr/SiNx multilayer films deposited on glass were obtained by magnetron sputtering and subsequent rapid thermal annealing (RTA) in N-2 at 0.5-2000Pa pressure. Annealing pressure influenced the radiation thermal resistance, which can directly determine the crystallization and thermochromic performance of the VOx-based multilayer films. The VO2 (M) film is very difficult to form under low annealing pressure because of insufficient oxygen and low-valence metal oxides in NiCrOx film. Therefore, the thermochromic performance is seriously deteriorated by the drastic diffusion between NiCrOx and VOx. Based on the phase transition temperature (T-c) and good crystallization, the wider process window of 80 Pa-300 Pa has been obtained successfully. Additionally, the films exhibit the optimal thermochromic performance with the solar regulation (Delta T-sol) of 18.4% and the luminous transmittance (T-lum) of 40.5%. Moreover, the T-c can be reduced to 54 degrees C by regulating annealing pressure without element doping. The results provide guidance for commercial production and quality consistency of VOx-based smart glass in building energy conservation.