Improving Both Efficiency and Stability of Inverted Polymer Solar Cells by Incorporating Carbon Dots as Cathode Modified Layer

In this paper, the water-soluble zero-dimension carbon materials, carbon dots (C-dots), were employed as cathode modified layer to enhance the performance of inverted polymer solar cells (PSCs). The results demonstrate C-dots modification can further smooth the surface and decrease the work function of ZnO, thus contributing to the charge extraction and suppressing the charge recombination, and then improve the device efficiency. Besides, the carbon dots covering on ZnO can reduce the directly contact between the ZnO and the NFAs, thereby inhibiting the photocatalytic effect of the ZnO, and moreover, the introduction of the carbon dots enables the electron transport layer interface to have superior energy level contact and higher rectification ratio, which further reduce interface carrier accumulation and recombination, and thus improve the device stability.