Highly efficient metal-free organic dyes for dye-sensitized solar cells

A solar-to-electric conversion efficiency of 5.1% is achieved with this new dye, compared to 5.8% for N3 dye under the same experimental conditions. Although these indoline dyes are slightly less efficient than N3 dye [cis-Ru(II)(2,2′-bipyridil-4,4′-dicarboxilic acid) (NCS)], the cost would be expected much lower because it does not contain any noble, rare metals in the structure and also it is easy to prepare specially for the mass production. Furthermore, indoline dyes are shown to be highly stable to photoredox processes by cyclic voltammogram.