Photoelectrochromic Film for Color Changing Windows

C.H. Han, S. Hong
Korea Institute of Energy Research,

Keywords: photoelectrochromic device, light intensity modulation, auto-tinting window, sunlight protection, photo-responsive coloring, self-bleaching


Our photoelectrochromic film has a pale yellow tint at its original state with average transmittance of 70% at 600 ~ 700nm. When it is exposed to sunlight, it turns to greenish blue and the transmittance of sunlight at 600 ~ 700nm can be reduced to around 20% and even more. Through the cooperative works with companies in developing new chromogenic materials that can be deposited below 150oC, we successfully demonstrate the flexible photoelectrochromic film that can reversibly tune its transmittance in response to sun light. The coloration time and bleaching time have been improved as 3min and 1hour, respectively, compared to the device of 5min coloration time and 5 hour bleaching time which was reported last year by us. Our photoelectrochromic film does not need external power to operate that can greatly reduce expenditure of installation and maintenance.