The dye regeneration mechanism involving the organic triphenylamine(TPA)dyes and cobalt-based redox mediator,[Co(bpy)3]2+/3+,were investigated using density functional theory(DFT)combined with the Marcus theory of electron transfer(ET).The influences of π-conjugated linker extension and rigidification on the regeneration process were studied here,computational results showed that the absorption spectra of TPA dyes exhibit red-shift in the maximum absorbance along with the π-conjugation extension of oligothiophene or the rigidification of the conjugated linker,however,the ET rates of regeneration reaction gradually decreased which due to the increased activation free energy(VAB)and decreased electronic coupling energy(VAB)).Thus,to acquire higher power conversion efficiency(PCE)of dye-sensitized solar cells(DSSCs),the matching between the dye and redox mediator should be further considered when continually broadening the absorption spectra of the dye,to realize effective dye regeneration.