Fully Discrete VO₂ Particulate Film with Ultra‐High Transmittance and Excellent Thermochromic Performance

Abstract Vanadium dioxide (VO₂) has attracted widespread attention due to its extraordinary thermochromic properties. Visually transparent VO₂ films hold great promise for applying in smart windows, smart radiative coolers, solar cells, and microwave absorbing windows. However, it remains a huge challenge to simultaneously achieve ultra‐high luminous transmittance (T_lum) and excellent thermochromic performance due to their contradictory relationship. Here, a fully discrete VO₂ particulate (FDVP) film is developed. It shows an ultra‐high T_lum of 92.7% due to the reflectance being significantly reduced. Below the phase transition temperature (T_c, 69.1 °C), it is highly transparent to near‐infrared (NIR) light, while above T_c, it blocks NIR light through the strong localized surface plasmon resonance (LSPR) effect, resulting in an excellent solar energy modulation (ΔT_sol) of 10.5% for smart windows. In addition, a 3.5 at.%W‐doped FDVP film exhibits a desired T_c of 25.8 °C, an extremely narrow hysteresis width (ΔT) of 4.6 °C, and good optical properties (T_lum = 92.0%, ΔT_sol = 8.2%). The performance represents a new milestone for thermochromic VO₂ films. This work will shed light on the structural design for high‐performance VO₂ films.