Controllable fabrication of perylene bisimide self-assembled film and patterned all-solid-state electrochromic device

A water-soluble perylene bisimide derivative of N,N-bis(2-phosphonoethyl)-3,4,9,10-perylenediimide (PPDI) was synthesized by introducing phosphoric acid units. PPDI self-assembled films were prepared controllably on hydroxylated ITO glass through a zirconium-phosphonate approach. There is a linear increase between the film thickness and the number of self-assembly layers. Electrochemical and spectroelectrochemical analysis reveal that the PPDI self-assembled films show excellent reversible redox behavior and cathodic electrochromic character which can be switched from a neutral orange-red color to deep purple color in the reduced state. In particular, the PPDI self-assembled film with 10 layers have good integrated performance in term of reasonable optical contrast (31%), fast switching time (0.75 s) and good cycle stability. A large-scale patterned all-solidstate electrochromic device (50 mm x 60 mm) was fabricated by utilizing PPDI self-assembled film as the electrochromic layer and the device shows obvious reversible electrochromism, which provides a new direction for the production of electrochromic device, like smart-window, sunglasses and electronic tags.