The effects of macrocycle and anchoring group replacements on the performance of porphyrin based sensitizer: DFT and TD-DFT study

Density functional theory and time dependent-density functional theory calculations have been carried out in an attempt to design new phthalocycanine based sensitizers that could be expected to improve the performance of the porphyrin based sensitizer YD2-o-C8. This was done through replacing the porphyrin macrocycle and carboxylic acid anchoring group of YD2-o-C8 by phthalocyanine macrocycle and cyanoacrylic acid anchoring group, respectively. The performances of the suggested cells could be expected to improve the efficiency of the reference dye YD2-o-C8 with Ti38O76, (TiO2)60, SiC, and SrTiO3 semiconductors. Macrocycle replacement assists in promoting the efficiency in the red shoulder of the spectrum more effectively than that of the anchoring group. The effects of the former structural modifications on cell performance are confirmed in terms of frontier molecular orbitals, energy gaps, semiconductor valence and conduction band edges, density of states, molecular electrostatic potentials, non linear optical performances, reorganization energies, UV-vis absorption and emission, life times of excited states, light harvesting efficiency, injection efficiency, charge collection, and free energy of regeneration.