▎ 摘　　要

Tetraphenylporphyrin (TPP) has been reported as the sensitizer of the dye-sensitized solar cells (DSSC). However, the efficiency is unsatisfactory because of the unobvious visible light absorption. Here we examine the improvement of the efficiency by using a sensitizer of cir-coronene graphene oxide quantum dot (GOOD) and TPP composite. The geometrical structures of the GOAD-TPP nanocomposites, as well as their separate components, are fully optimized by employing the first-principles density functional theory (DFT). The frequency analysis is used to confirm the energy stability of the obtained structures and time-dependent DFT (TDDFT) is used for the calculations of the optical absorption. We use the I-/I-3(-) electrolyte, and the conduction band minimum of TiO2 electrode as the example to examine the feasibility of the nanocomposites as the sensitizer of DSSC by evaluating the energy levels, the charge spatial separation of the frontier molecular orbitals and electron transfer of the nanocomposites. The results demonstrate that the GOQD(18OH)-TPP can meet the necessary conditions of the sensitizer of DSSC. Besides, the most favorable is because of its larger driving force and light-harvesting efficiency, the suitable open-circuit voltage value, and enhancement light absorption. The results implicate that this one is the most promising sensitizer candidate of DSSC. These findings can provide a useful reference for developing the sensitizer of DSSC or designing the materials to harvest solar energy based on the nanocomposites of GOQD-TPP.