Using density functional theory (DFT) and time-dependent DFT in different levels, we have systematically studied new porphyrin-based dyes with A-π-D structures focusing on optical absorption, light harvest efficiency, ground state oxidation potential, excited state oxidation potential, and natural transition orbitals. Compared with existing dyes, we find that these new dyes have wide absorption regions (400-1000 nm) with high molar extinction coefficients, and display good energy level alignment for efficient injection of electrons and fast regeneration of the oxidized dyes.