Spray-processable, large-area, patterned and all-solid-state electrochromic device based on silica/polyaniline nanocomposites

The silica/polyaniline (SiO2/PANI) nanocomposites were successfully synthesized by chemical oxidative polymerization. The SiO2/PANI nanocomposite film shows improved electrochromic properties, compared with dense PANI film. The all-solid-state electrochromic device based on SiO2/PANI nanocomposite film (ECD-SiPN) is fabricated by assembling SiO2/PANI and poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) films as the anode and cathode, respectively. Large optical modulation (62% at 700 nm), short switching time (5.7 s for bleaching, 3.2 s for coloring), high coloration efficiency (135.1 cm2/C), and good cycling stability are realized by the ECD-SiPN. And the spray-processable, large-area and all-solid-state electrochromic device also maintain good electrochromic performance. Furthermore, the high-quality patterned all-solid-state electrochromic display was successfully prepared by assembling spray-deposited patterned silica/polyaniline (SiO2/PANI) nanocomposite film as electrochromic active layer and spray-coated patterned PEDOT:PSS film layer as counter electrode. The patterned electrochromic display exhibits promising features for applications in electronic books, large area electronic cards, large area electronic advertising boards, energy efficient displays etc.