Associate Professor Takuya Nakashima and Professor Tsuyoshi Kawai, Laboratory of Photonic Molecular Science, Graduate School of Materials Science

Prof. Takuya Nakashima and Tsuyoshi Kawai in Graduate School of Materials Science, Nara Institute of Science and Technlogy, NAIST, have recently invented a new photo-electrochromic molecular material which indicates electrochromic fading from photochromic colored state with current efficiency higher than 2000%. Usual electrochromic smart-window system modulates their optical transparency with electric current, which enables to save energy consumption for the temperature controling in buildings and transportations. Their typical example is seen in an urban high-tech airplane Boeing 787. Future of this class of smart window will be much smart. By using new molecular material from NAIST, energy consumption for coloration and fading process can be much decreased. That is, the new material is simultaneously colored under UV light involved in the sunlight and can be bleached by electrical current, thus one-half of power consumption should be decreased. Moreover, the current efficiency of bleaching process is more than 2000%, which indicate 95 % of power consumption for bleaching can be reduced, providing chance to save 98% of total energy consumption for coloration and fading.
This new invention was recently reported in a high level scientific journal, Journal of American Chemical Society with detailed scientific background including theoretical and chemical analyses.