Deposition and Characterization of Zr and Nb Doped VO<sub>2</sub> Thin Films by MOD

For the application of thermochromic smart windows, it is important to realize high visible light transparency, modulation of infrared transmission, and phase transition temperature around room temperature. For this purpose, vanadium dioxide (VO2) thin films co-doped with niobium and zirconium were synthesized by metal-organic decomposition (MOD) method on glass substrates. First, the effect of Zr doping on the transparency of VO2 thin films was investigated as a preliminary experiment. 3 mol% Zr doping improved the visible light transmittance of VO2 thin films from 49% to 56%, and the phase transition temperature decreased from 81°C to 74°C without decreasing the switching ratio in the infrared region. Then, the effect of Zr and Nb co-doping on the transition temperature of VO2 thin films was investigated. The VO2 thin film co-doped with 3 mol% Zr and 4 mol% Nb could significantly decrease the phase transition temperature from 74°C to 48°C while nearly maintaining the visible light transmittance.