High‐Performance Thermochromic VO2‐Based Coatings Deposited by Roll‐to‐Roll High‐Power Impulse Magnetron Sputtering

Thermochromic vanadium dioxide (VO 2 ) undergoes a reversible semiconductor‐to‐metal transition, a property that can be exploited for reduction of the energy consumption in buildings using smart windows. Herein, high‐performance thermochromic three‐layer ZrO 2 /V 0.98 W 0.02 O 2 /ZrO 2 coatings prepared on ultrathin flexible glass (0.1 mm) without any post annealing in a pilot‐scale roll‐to‐roll deposition device are presented. The V 0.98 W 0.02 O 2 layers are deposited using a reactive high‐power impulse magnetron sputtering with an oxygen flow control at a substrate temperature of approximately 350 °C. The optimized coatings (width of 0.3 m and length over 2.6 m) exhibit a transition temperature of 28 °C, an integral luminous transmittance over 50%, and a modulation of the solar energy transmittance of about 10%. The deposition process is optimized, and the elemental composition (Rutherford backscattering spectrometry), design (field‐emission scanning electron microscopy), phase composition (X‐ray diffraction), and thermochromic properties (spectrophotometry) of these high‐performance VO 2 ‐based coatings in the context of potential for commercial applications are characterized.