A fluorescent quenching performance enhancing principle for carbon nanodot-sensitized aqueous solar cells

Abstract

We report a fluorescent quenching principle capable of markedly enhancing the conversion efficiency of carbon nanodots (CNDs)-sensitized aqueous solar cells (CNDs-ASCs). A conversion efficiency of 0.529%, over 4-times of the best conversion efficiency reported for CNDs-sensitized solar cells, is achieved with a cell constructed using CNDs as the sensitizer and aqueous I−/I3− electrolyte serving a dual-function as the recombination blocker (fluorescent quencher) and redox mediator. The results confirm that the significantly enhanced utilization efficiency of the photo-excited electrons resulting from the efficiently quenched fluorescent emission of CNDs sensitizer by I− is responsible for the markedly improved conversion efficiency of CNDs-ASCs. The findings of this work validate a principle that could be widely applicable for enhancing the performance of solar cells employing other fluorescent quantum dots/nanodots sensitizers.