Improving the electronic and optical properties of Carbz-PAHTDDT-based dyes through chemical modifications

Abstract: To investigate geometric and electronic structure, a theoretical study is performed on the Carbz-PAHTDDT (S9) organic dye sensitizer. This dye has a reported promising efficiency when coupled with ferrocene-based electrolyte composition. The present study indicated that the long-range correction to the theoretical model in the time-dependent density functional theory is important to produce accurate absorption wavelengths. In the present study, the chemical structure of the original Carbz-PAHTDDT dye on the {\pi}-conjugated bridge is also rationally changed to produce new dyes aiming at enhancing the spectral response as a desirable property of organic dyes in DSSC application. The theoretical studies on the new dyes have shown a significant red-shifting and broadening of their absorption spectra.