High-performance thermochromic VO₂-based coatings with a low transition temperature deposited on glass by a scalable technique

We report on high-performance thermochromic ZrO₂/V_0.982W_0.018O₂/ZrO₂ coatings with a low transition temperature prepared on glass by a low-temperature scalable deposition technique. The V_0.982W_0.018O₂ layers were deposited by a controlled high-power impulse magnetron sputtering of V target, combined with a simultaneous pulsed DC magnetron sputtering of W target to reduce the transition temperature to 20-21 °C, at a low substrate surface temperature of 330 °C in an argon-oxygen gas mixture. ZrO₂ antireflection layers both below and above the thermochromic V_0.982W_0.018O₂ layers were deposited at a low substrate temperature (< 100 °C). A coating design utilizing a second-order interference in the ZrO₂ layers was applied to increase both the luminous transmittance (T_lum) and the modulation of the solar transmittance (ΔT_sol). The ZrO₂/V_0.982W_0.018O₂/ZrO₂ coatings exhibit T_lum up to 60% at ΔT_sol close to 6% for a V_0.982W_0.018O₂ thickness of 45 nm, and T_lum up to 50% at ΔT_sol above 10% for a V_0.982W_0.018O₂ thickness of 69 nm.