▎ 摘　　要

Optimizing the interfacial properties between perovskite and carbon electrodes has always been an important way to improve the photoelectric conversion efficiency (PCE) of carbon-based perovskite solar cells (C-PSCs) and facilitate their commercialization. In this paper, nitrogen-doped graphene quantum dots (N-GQDs) with fluorescent properties were successfully prepared using inexpensive coal as raw material by a facile and environmentally friendly chemical reagent oxidation. The results show that the electron-rich pyridinic nitrogen in N-GQDs can act as Lewis bases to form coordination bonds with uncoordinated lead ions by sharing electron pairs, thereby reducing the defect density and nonradiative recombination of photo-generated electron-hole, and extending lifetime of charge carriers. In addition, due to the passivation of N-GQDs, the hysteresis effect of the device is significantly reduced and the long-term stability is also improved. By optimizing the concentration, the PCE of C-PSCs achieved a max-imum of 14.31%, which was improved by 20.25% compared with 11.90% of the pristine C-PSCs. This work provides a facile, environmentally friendly and efficient strategy for improving the overall performance of C-PSCs using inexpensive coal-based N-GQDs.(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.