DFT and TD-DFT study of novel triphenylamine based organic dyes for dye-sensitized solar cells

Abstract

Dye Sensitized Solar Cells (DSSC) are a low-cost alternative to our renewable energy sources in recent decades because they have a potential to achieve high power conversion efficiency (PCE) and their devices are easy to manufacture. For a better understanding of the charge transport process involved in the DSSCs, we studied the effect of conjugation on the electron structure and optical properties of triphenylamine derivatives, we carried out a theoretical study on six organic dyes synthesized by Yu et al. In this work, we studied the effect of different substituents on the electronic and optical properties of six triphenylamine dyes using quantum chemistry methods such as DFT and TDDFT. These calculations were undertaken by the functional hybrid exchange and correlation B3LYP and the base 6-31G (d, p). This model allowed us to determine the optimized structures and the electronic and optical properties (EHOMO, ELUMO, Egap, $\lambda_{abs}$, Voc….) Of various dyes studied. We note that the dye P6 exhibits the lowest gap energy and reasonable Voc value. We also simulated the UV-visible spectrum by using the TD-DFT with two functionals CAM-B3LYP and WB97XD to give a look for their effect on optical properties introducing the effect of the solvent (THF). Our results show that the six studied dyes absorb in the visible and are a good promising choice for DSSCs.