Reduced graphene oxide layered WO₃ thin film with enhanced electrochromic properties

The electrochromic (EC) properties of inorganic-organic hybrids of tungsten oxide/reduced graphene oxide (WO₃/rGO) thin films were examined. Using hydrothermal method WO₃ nanorods were deposited on a conducting Indium-doped tin oxide (ITO) glass substrate. In succession, the reduced graphene oxide thin film was coated on WO₃ thin film using improved Hummers method. The structural, morphological, optical, and electrochromic responses of WO₃, rGO, and WO₃/rGO films are illustrated. Compared with pure WO₃ film, WO₃/rGO composite film demonstrates improved EC performance because of enhanced double insertion/extraction of ions and electrons. It realizes a large optical modulation (58.8% at 633 nm) with a significant increase in Coloration Efficiency (CE) and EC stability.