Photopatternable electrochromic materials from oxetane precursors.
Conjugated thiophenoazomethine triads containing an acid sensitive oxetane group were prepared. The solution processable monomers were immobilized on glass and ITO coated glass substrates by photoacid induced cationic ring-opening polymerization (CROP) of the oxetane moiety. Photolithography using a photoacid generator and photosensitizer were used to pattern an electroactive polymer. Micro- and macroscale patterns ranging between 20 μm and 50 mm were possible with the electrochromic materials. The photopolymerized azomethine remained electroactive, and it could be repeatedly switched electrochemically between its neutral (mauve, λmax=535 nm) and oxidized (blue, λmax=585 nm) states without degradation. The electrochromic properties were evaluated in a simulated device where the colors were successfully cycled between blue (oxidized) and purple (neutral) states with applied biases of +0.6 V and -0.6 V vs Fc/Fc+ under ambient conditions without significant color fatigue or degradation.
Laboratoire de caractérisation photophysique des matériaux conjugués, Département de Chimie, Pavillon JA Bombardier, Université de Montréal , CP 6128, succ. Centre-ville, Montréal, Québec, Canada H3C 3J7.
Antoine
A
Leliège
Satyananda
S
Barik
W G
WG
Skene