Exploring the Effect of π-spacers on D-D-π-A Based Triphenylamine Dyes for Dye Sensitized Solar Cell Applications - Computational Approach

The effect of different pi spacers in D-D-pi-A based triphenylamine sensitizers is studied computationally for DSSC application. Tetrahydroquinoline and triphenylamine groups are chosen as electron donor groups. The ground state structure, HOMO-LUMO energy studies, Local minimum energy, dipole moment and linear polarizability of the D-D-pi-A based triphenylamine dyes are analyzed by Density functional theory (DFT). The spectroscopic properties of triphenylamine based dyes are analyzed by Time dependent density functional theory (TD-DFT). The free energy studies of electron injection and dye regeneration are also calculated based on the DFT and TD-DFT results. The computational results show that the number and position of the pi-spacers largely affect the electronic, optical and spectroscopic properties. The calculated results of the D-D-pi-A based triphenylamine sensitizers show that, the THQ-TPA-6 is more efficient compared to other sensitizers for DSSC application.