Lindqvist polyoxometalates as electrolytes in p-type dye sensitized solar cells†
The development of new redox couples provides a clear strategy to improve power conversion efficiency (PCE) in p-type dye-sensitized solar cells (p-DSSCs) through enabling improvements in open-circuit voltage (VOC). In this work we report the use of molybdenum and tungsten containing Lindqvist polyoxometalates (POMs), [TBA]2Mo6O19 and [TBA]2W6O19, as an alternative to the traditionally used I−/I3− redox mediator in p-DSSCs. POM electrolytes are cheap and easy to synthesize, air stable and transparent, making them suitable for tandem solar cell applications. Electrolytes were evaluated using a simple testing device to benchmark the respective devices. Up to a 5-fold increase in VOC was observed for p-DSSCs employing electrolytes with POMs upon comparison with traditionally used I3−/I−, while short-circuit photocurrents with the same order of magnitude were observed under identical dilute conditions.