Photo-electrodes decorated with carbon quantum dots: Efficient dye-sensitized solar cells

Abstract

In this study, the blue and green carbon quantum dots (CQDs) are synthesized and applied to the photo-electrodes of dye-sensitized solar cells (DSSCs). The DSSCs exhibited high power conversion efficiency because of the conversion of ultraviolet to the visible region in photo-anode, and good catalytic activity in the photo-cathode. The blue color CQDs (BCQDs) and green color CQDs (GCQDs) are synthesized from the citric acid in a single pot process. We examine the influence of both CQDs decorated on photo-anode and photo-cathode and both photo-electrodes on the photovoltaic performance of the DSSCs. Furthermore, the DSSCs are studied by electrochemical impedance spectroscopy, cyclic voltammetry, and Tafel polarization data to study the charge transfer kinetics. The better performance observed from the DSSCs due to enhanced charge carrier collection through the CQDs. The photovoltaic results of DSSCs shown that the best efficiency shown by DSSC, which fabricated by both photo-electrodes decorated by CQDs.