Intense pulsed light sintering of vanadium dioxide nanoparticle films and their optical properties for thermochromic smart window

Abstract

As cost-efficient and large-scalable fabrication, solution processing has been developed to prepare vanadium dioxide (VO2) films for thermochromic smart windows that can modulate infrared radiation in response to changes in ambient temperature while maintaining visible transmittance. Herein, we report for fabrication of VO2 films from ball-milled VO2 nanoparticle ink using intense pulsed light (IPL) sintering. The VO2 films on quartz substrates were prepared by spin coating. The prepared films were sintered by IPL in air with various voltages from 1400 to 2000 V with the fixed conditions of 4 ms, 400 pulses and 1 Hz. IPL sintering of VO2 nanoparticle ink led to granular films which were sintered at higher voltages since IPL irradiation was able to evaporate solvent including polymers in the ink, and sinter VO2 nanoparticles. The VO2 films IPL sintered at 2000 V exhibit luminous transmittance of over 46.3% and solar transmittance modulation of 11.2%. These results reveal that IPL sintering is substantial progress in terms of long-time and high-temperature post annealing for fabrication of solution-based thermochromic films. Keywords: Intense pulsed light sintering, Vanadium dioxide, Nanoink, Thermochromism, Smart window, Solution process