Dye-Sensitized Solar Cells (DSSC): A DFT and TD-DFT Theoretical Investigation of the Effect of Inserting Auxiliary Acceptors on Triphenylamine based Dye Performances

Abstract

Abstract. Triphenylamine (TPA) molecules have shown a highly donors efficacity in DSSC field. This work takes into consideration, based on a triphenylamine based dye C213, three novel organic sensitizers were designed to investigate the effect of introducing an auxiliary acceptor on their properties. With a D-A2-π-A1 architecture of the investigated dyes, we have optimized their geometry, studied their frontier molecular orbitals and calculated their gap energies by using density functional theory (DFT). TD-DFT calculations were then used to determine the maximum absorption wavelength (λmax). The results show that insertion of π-conjugated linkers on the structure of the reference dye C213 has enhanced the maximum wavelength absorption (λmax) and decreases the gap energy, which is favorable for DSSC. Indeed, among the three designed compounds, C213-THp have shown the best wavelength value with λmax= 759 nm and a narrow gap energy with Egap=1,94 eV.