<title>Development of fast-response electrochromic devices on polymeric substrate</title>

Abstract

The development of full solid-state electrochromic (EC) devices on polymeric substrate is under way within a CEC BRITE-EURAM project (Project `FREDOPS', BE-4137) carried out by four industries, two universities and two research centers from Belgium, Denmark, France and Italy. Specific goal of the project is to develop a Fast Response Electrochromic Device on Polymeric Substrate (FREDOPS); in order to satisfy the required range of specifications in terms of fast response, long term performance and high contrast ratio, several systems based on different materials have been tested. The full cells consist of an electrochromic material layer and a counter-electrode, inserted between two PET/ITO layers and separated by a polymeric electrolyte. Different types of polymeric electrolytes, counter-electrodes and electrochromic layers have been developed, studied and checked. Full devices have been assembled using different combinations. Voltammetric and spectrophotometric measurements have been executed to check the electrochromic behavior of the developed layers in half and full cells. Comparison of the electrochromic performances of different materials based cells has led to the rejection of several solutions due to poor performance and incompatibilities between layers. The present paper discusses these results in order to indicate the best foreseen solutions.