Graphene nanomesh (GNM)-based optoelectronics integrated with quantum dots (QDs) are investigated in this article. The charge transfer mechanism in the QDs/GNM interface is probed in four terminal gated FET-type photodetectors. The insulating ligand is used to make the GNM/ligand/QDs vertically behave like a metal/insulate/semiconductor (MIS) structure to facilitate the charge tunnelling. With the current constraint effect of the GNM and the effective charge tunnelling, a high-performance photodetector is fabricated with higher responsivity, higher on/off ratio and shorter response time. The results of our analysis and experimental approach can be extended to future graphene-based photodetectors, as long as suitable ligands and an effective architecture are chosen for this type of device.