ITO-free large area PDLC smart windows: a cost-effective fabrication using spray coated SnO2 on an invisible Al mesh

Theoretical and experimental studies are performed to establish the importance of a thin overlayer on metal mesh as an ITO-alternative transparent conducting electrode for liquid crystal smart windows where a uniform electric field is essential.

Graphene Oxide Coated Silver Nanofiber Transparent Conducting Electrode

We fabricated a transparent conducting electrode composed of graphene oxide (GO) and silver (Ag) nanofibers. The graphene oxide was spray-coated on the Ag nanofiber film, which was fabricated by electrospinning process. Ag/poly(vinyl alcohol) ink was fabricated in a polymer matrix solution using the solgel method. The sprayed film was sintered at 200 ^oC for 100 min under H₂/Ar atmosphere. The optical transmittance of the transparent electrodes was measured by UV/VIS spectroscopy, and sheet resistance was measured using I-V measurement system. As the amount of GO sprayed on the nanofibers increased, the diameters of the nanofibers increased, therefore, the transmittance of the electrode linearly decreased. However, the conductivity of the electrode increased. This is because the sprayed GO filled the gap between the nanofibers, and GO deposited on the surface of the nanofibers will form more effective electron pathways, resulting in increased conductivity. The GO-Ag nanofiber electrode also exhibited excellent environmental stability, and the sheet resistance of the electrode remained very stable during 30 days testing. The lowest sheet resistance of the transparent electrode was 250 ohm/sq with approximately 83% transparency at a wavelength of 550 nm. This excellent electrical properties and environmental stability might facilitate applications of the GO-Ag nanofiber electrode in optoelectronic devices.