Selective Photo-thermal Conversion of Tungsten Oxide Sol Precursor for Electrochromic Smart Window Applications

A photothermal conversion of sol precursor by selective laser sintering (SLS) process has opened a novel patterning way for advanced electronic applications. The SLS process bases on the photo-thermal-chemical effect and features for high precision, fast processing, and room temperature processability without inert gas. Therefore, the effectiveness of the interaction between the nanomaterials and laser has examined on the various conductive metal nanomaterials such as gold, silver, and copper. Although the laser sintering process has shown many achievements on the metal nanomaterials, it has rarely studied for the interaction for the metal oxide nanomaterials. In this study, WOx thin film layer employs the SLS process for post-processing which enables patterning and annealing simultaneously with inducing photochemical redox reaction as well as photothermal effect. The SLS-processed WO3 thin film has shown similar electrochemical performances for the electrochromic application to the thermal annealed WO3 thin film. We have demonstrated a facile and fast fabrication of the electrochromic device (ECD) with the SLS-processed WO3 thin film layer.