A study of Electrochromic thin films and Devices by Photothermal Deflection Technique

Abstract

Recently, electrochromic thin films and thin film devices have attracted more and more interest because of strong possibility to act as smart windows and smart glass that may be widely used in the daily life[1]. The electrochromic thin film devices usually have a five layers structure: an actual electrochromic layer, an ionic conductor and an ion storage layer are sandwiched between two outer transparent electrical conductive layers, WO3 film is used as the actual electrochromic films in the general studies. The coloration and bleaching are accomplished when positive ions (Li+, H+ etc. )are moved from the ion storage, via the ionic conductor, into the electrochromic layer, or in the inverse direction. Currently, the electrochromic thin films or thin film devices are characterized by electrochemical analysis and optical spectral transmittance measurement. In fact, the electrochromic effect is a spectral absorption modulation, the investigation of the optical absorption variation during the electrochromic process may offer us more information about the process.