Enhanced power conversion efficiency in iridium complex-based terpolymers for polymer solar cells

Abstract

Polymer solar cells: low concentrations of Iridium complexes boost efficiency Only 1 mol% of Ir complex can do the trick to greatly enhance the efficiency of PTB7-Th: fullerene polymer solar cell from 7.9 to 9.2%. A collaborative research led by Youtian Tao from Nanjing Tech University, China shows that the power conversion efficiency of PTB7-Th: fullerene polymer solar cell can be enhanced by conjugating extremely low ratio of heavy metal Ir complex via ancillary ligand. The conclusions have proved robust for PTB7-Th with different molecular weight, different Ir complex concentrations and different cathode interface materials such as calcium or PDIN. These results prove the importance of heavy metal complex for highly efficient photovoltaic devices and demonstrate a promising design approach toward more efficient photovoltaic polymer donor materials.