The investigation of the central metal effects on the porphyrin-based DSSCs performance; molecular approach

•The performance of the porphyrin-based dyes in DSSC by replacing the metal inside the macrocycle cavity has been assessed.•Based on the arrangement of energy levels of the materials involved in DSSC, we propose the dyes are proper as sensitizers.•The behavior of the IPCE and LHE as a function of wavelength has been presented.•Linear correlation between the DFT conceptual reactivity indices and the photovoltaic parameters has been obtained.

In this work, we have investigated the insertion of the different metal atoms, -Ca, -Mg and -Zn, into the porphyrin-based dyes for access to more efficient photovoltaic processes in the dye-sensitized solar cells. The photovoltaic processes have been described through the electronic properties of the dyes in the ground and excited states and quantum chemistry descriptors of them. The structural, electronic and spectroscopic properties of the dyes have been obtained by using the natural bond orbital, density functional theory (DFT) and time-dependent-DFT calculations. The preference of applying the metalloporphyrins, especially the Ca-porphyrin complex, in the solar cell is correlated with more proper photovoltaic properties than the free-base porphyrin. Proper photovoltaic properties of the metalloporphyrins are originated from the acceptable electronic chemical potential, electrophilicity indices and electron injection force from the dye to TiO2.

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