The fourth lecture of the day was by Ravi Kumar Kannaparthi, Assist. Professor, Dept. Of Chemistry, Central University of Kerala and his talk was on dye sensitized solar cells. The working principle of a dye sensitized solar cell draws from photosynthesis .i.e. a light sensitive molecule gets excited by light energy. It also works with diffuse light. Some of the possible products that utilise this principle have already been commercialised like solar powered back packs and keyboards.