In view of their structural versatility and high photoelectric capabilities, nitrogen-doped carbon quantum dots (N-CQDs) have been observed to exhibit promising potential as functional material for improving the efficiency of chalcogenide-based solar cells. In this work, the fabrication of N-CQDs using fennel seeds was done in a process that involved the steps of drying, grinding, hydrothermal process, filtration, centrifugation, and dialysis. Characterization methods such as UV-Visible spectroscopy, fluorescence spectroscopy, and SEM analysis were used to analyze and assess the uniformity of the produced particles when used as a component of solar cells. As revealed by characterization studies, it was clear that the obtained N-CQDs had a suitable energy-level position and good luminescence capabilities. On inclusion within the charge-transport interface layer of the solar cell, its efficiency improved to 20.34%, and the short-circuit current density rose to 23.94 mA cm−2. Moreover, N-CQDs have the potential to reduce the level of interfacial defects and the complexity of the carriers, hence reducing the hysteresis effect. The hydrophobic nature of the quantum dots prevented moisture penetration and consequently resulted in 51% enhancement of the CQDs stability.
