▎ 摘　　要

Solar Cell with TiO2-Graphene Quantum core/shell heterostructure synthesized by surface functionalization route is used for the present study. The structural properties of Graphene Quantum Dots (GQDs) coated TiO2 are confirmed by XRD, Raman, SEM, TEM and mapping analysis. Energies of the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) of the GQDs against vacuum are determined using cyclic voltammetry technique and ultraviolet photo electron spectroscopy. When compared to the bare devices, J-V characteristics of the GQDs incorporated solar cell show an enhancement in efficiency around 38% and J(sc) of 48%. Moreover, TiO2-GQD (TG 10) device pre and post treated with Titanium Tetra Isopropoxide (TTIP) shows the highest power conversion efficiency (PCE) of 5.1% which is similar to 65% enhancement when compared to untreated TG 10 based cell. This enhancement is due to higher light harvesting capacity, reduction in charge transfer resistance (R-ct) at the interface, increase in life time of carriers and increase in charge transfer rates.