Significant change in optical and thermochromic properties for VO 2 films post-treated by low-energy argon ions

Modification in the optical and thermochromic properties of VO2 films induced by argon ion irradiation were investigated. VO2 films prepared by direct-current reactive magnetron sputtering on fused silica were irradiated with 500 eV argon ions. Compared with the pristine VO2 film (ΔH = 16 °C and Tc = 62 °C), the film irradiated by argon ions had a narrower ΔH (∼11 °C) and lower Tc (∼53.5 °C). Furthermore, the irradiated film showed higher visible transmittance than the pristine film. The significant reduction in phase transition temperature and thermal hysteresis width can provide an available solution to regulate the thermochromism of VO2 films by low-energy argon ion irradiation.