N-GQDs modified core–shell structure ZnCdS/N-GQDs@ZnS for enhancing photoelectric properties

In this paper, core–shell quantum dots were successfully synthesized by condensation reflux at low temperatures using reduced glutathione as a capping agent. The effects of core–shell structure and N-doped graphene quantum dots (N-GQDs) on the performance of ZnCdS/N-GQDs@ZnS were studied. The results demonstrate that ZnCdS/N-GQDs@ZnS have strong photoelectric characteristics after the core–shell structure was produced, with a photocurrent of 7 × 10 − 6 A/cm 2 , which was 3.3 times as high as that of the core quantum dot ZnCdS/N-GQDs. This performance boost was ascribed to the core–shell structure, which may reduce surface imperfections in the core quantum dots and facilitate electron and hole separation and transport. At the same time, the presence of N-GQDs helps to improve the photoelectric performance of composite materials. The photocurrent of ZnCdS/N-GQDs@ZnS was twice as large as the ZnCdS@ZnS. This was because N-GQDs have good electron transport capabilities and facilitate the fast movement of electrons. The Mott–Schottky and electrochemical impedance studies also reveal that the synergy between the core–shell structure and N-GQDs can improve the photoelectric characteristics of the materials.