Window coatings of varying optical properties can be helpful to improve energy efficiency in buildings. A new research studies the energy-saving prowess of thermochromic vanadium oxide (VO2) coatings on ultra-thin flexible glass for transparent building components. VO2, a dynamic material altering its transmittance in response to temperature changes, holds promise for enhanced energy efficiency.

Deployed through a continuous roll-to-roll sputtering process, the 70 nm thick VO2 layer, nestled between two 170 nm zirconium oxide layers, achieved a solar modulation of 9.6% with a luminous transmittance of 50%. The transition temperature, a comfortable 22°C, signals the shift between infrared transparent and opaque states. While combinations with low-e coatings showed limited benefits, stand-alone thermochromic coatings emerged as a great solution for cooling-dominated energy demands in buildings.