Performance of metalloporphyrin malonic acids as dye sensitizers for use in dye-sensitized solar cells assessed by density functional theory

The performance of metallo (Zn, Cd, Hg) tetra (4-methylphenyl) porphyrin malonic acids as dye sensitizers for use in dye-sensitized solar cells (DSSCs) is assessed by means of ab initio molecular electronic structure calculations. The results reveal that malonic acid side chain cannot be described as an acceptor moiety, and the photo-to-current conversion efficiencies of the DSSCs that are based on organic semiconducting Cd and Hg tetra (4-methylphenyl) porphyrin malonic acid donors and a series of oxide semiconducting acceptors are expected to be greater than the reference porphyrin dye Zn tetra (4-methylphenyl) porphyrin malonic acid under standard global AM 1.5 solar conditions. This result is confirmed and characterized in terms of charge transfer, band gaps, density of states, polarizabilities, dipole moments, molecular electrostatic potential contours, electronic absorption energies, and infrared vibrational frequencies. The study emphasizes the role of metal centers, and provides alternatives to DSSCs with expensive materials.