Screen-printed electrochromic displays based on nanocrystalline electrodes

Screen printed electrochromic reflective displays, based on nanocryst. metal-oxide working electrodes derivatized with org. electrochromophores, have been developed. Segmented devices up to the size of 200 cm2, primarily designed for information sign applications, have been prepd. using industrial low-cost processes. It is shown that adequate module prepn. provides aesthetically attractive (paper-like) displays with bistable function (memory of approx. 20 min in the colored state) and low power consumption. The devices function well at temps. down to -20°C, sustain switching stability of at least two million cycles, and show promising stability under UV illumination, temp. storage (-20°C to +80°C) resp. humidity.