Direct Patterning of Tungsten Oxide Nanoparticles via Laser Ablation Process for a Digital Informative Display

This study focuses on the fabrication and characterization of a tungsten trioxide (WO₃) electrochromic device (ECD) <i>via</i> laser ablation. The fabrication process involves the deposition of a WO₃ thin film on a fluorine-doped tin oxide (FTO) substrate using spin coating and selectively removing the WO₃ and FTO layers through laser ablation. The resulting patterned WO₃ is assembled on the substrate with a gel-type electrolyte and a cover FTO substrate to construct the ECD. The fabricated ECD exhibits considerable color change and effectively blocks infrared wavelengths. X-ray diffraction analysis confirms the complete removal of the WO₃ and FTO layers during laser ablation. UV/VIS spectrometry and X-ray photoelectron spectroscopy analysis demonstrate the difference in transmittance and the changes in the tungsten ion oxidation state for the WO₃ ECD. The fabricated WO₃ ECD can be utilized for informative display applications, generating binary barcodes. In summary, this study presents the fabrication of a tunable WO₃ ECD with potential applications in display devices.