POLYMER-BASED SOLID-STATE ELECTROCHROMIC DISPLAY DEVICE USING PVA COMPLEX ELECTROLYTES

Electrochromic display device has been fabricated using poly vinyl alc ohol (PVA) films complexed with H3PO4 and H2SO4, as electrolyte and WO 3 film as electrochromic material. The device response such as coloura tion and bleaching times are determined from the variation of transmit ted light intensity measurement at 450 nm wavelength. Various device p arameters such as colouration efficiency, transmissive contrast ratio and transmittance modulation have been evaluated and results are analy sed. The complex electrolyte (H+/VA = 0.12) of PVA-H2SO4 shows maximum change in optical density (Delta OD = 0.13) due to its high conductiv ity value. It is observed that transmissive contrast ratio is dependen t on acid concentration and increases with injected charge density.