Influence of Additives on Zinc Oxide-Based Dye Sensitized Solar Cells

In order to enhance the power conversation efficiency of dye sensitized solar cells (DSSCs), various trials have been reported. In this work, composites of n-type semiconductors, ZnO and ZrS2 were fabricated in DSSCs. In addition, the effect of addition of carbon dots on them was assessed. When 10 wt% of ZrS2 was mixed with ZnO, the power conversion efficiency achieved 1.6 times of that of ZnO but the coexistence of carbon dots and ZrS2 in ZnO DSSC resulted the decrease of the power conversion efficiency. ZrS2 forms an n-n heterojunction with ZnO and contributes to the fast transfer of electrons to the conductive electrode substrate. Meanwhile, when carbon dots are added to ZnO/ZrS2(10 wt%) DSSC, the electrons generated and transferred to ZrS2 should recombine with holes generated and transferred to photosensitizer. These situations are compared with a composite system of ZnO/carbon dots previously reported and suggest us the selection of preferable combinations of composite DSSCs.