Abstract

Since the seminal Nature paper by O’Regan and Grätzel in 1991 [1] the highest efficiencies of dye-sensitized solar cells (DSC) have been achieved using the iodide/tri-iodide redox system. A disadvantage of this mediator is the large internal losses caused by the fact that it is a two-electron redox couple. In 2010 we made a breakthrough by using one-electron transfer redox systems such as cobalt-complexes, in combination with a new generation of organic dyes, which efficiently prevents recombination losses [2]. This discovery was quickly embraced by Grätzel and co-workers, and the new world record for DSC is at present 13.0% by using a Co-complex redox couple and a porphyrin [3]. Our focus now is to develop high efficiency DSSC utilizing different colors such as blue, green, yellow and red aiming for aesthetically attractive applications in for example building integration.

© 2015 Optical Society of America