An electron-deficient group, 2,3-diphenylquinoxaline (DPQ), is incorporated as an auxiliary acceptor into the different positions of the porphyrin (Por) based donor-pi bridge-acceptor (D-pi-A) dye (FNE57) to construct D-A'-Por-pi-A (FNE58) and D-Por-A'-pi-A (FNE59) configurations. The incorporation of DPQ unit between the donor and porphyrin unit has negligible influence on the absorption property, whereas the DPQ unit located between the porphyrin unit and acceptor significantly increases the absorbance for the Soret band and the valley between the Soret and Q bands. Theoretical calculation reveals that incorporating the DPQ unit adjacent to the acceptor is more advantageous to delocalize the lowest unoccupied molecular orbital and enhance the electronic asymmetry, which facilitates the intramolecular charge transfer. The effect of DPQ unit and its linkage position on the performance of related quasi-solid-state dye-sensitized solar cells (DSSCs) is systematically investigated. The quasi-solid-state DSSC with sensitizer FNE59 displays a power conversion efficiency of 6.02%, which is 23% and 51% higher than those for FNE57 and FNE58 based DSSCs. Our studies facilitate the understanding of the crucial importance of molecular engineering and pave a new path to design novel porphyrin based sensitizers for highly efficient DSSCs.