Accurate predictions of the electronic excited states of BODIPY based dye sensitizers using spin-component-scaled double-hybrid functionals: a TD-DFT benchmark study

Abstract

The excitation energies of 13 BODIPY dye sensitizers are benchmarked by means of TD-DFT, using 36 functionals. Spin-component-scaled double-hybrid (DSD) functionals are found to show the best performance.

Assessment of time-dependent density functionals for the electronic excitation energies of organic dyes used in DSSCs

“…This approximation does not alter the electronic structure and spectra of these highly conjugated systems, and is a valid strategy used in order to reduce the computational cost. 44,107–109 The purpose of the long hydrophobic linear alkyl side chains is to prevent dye recombination with the semiconducting oxide electrode in operational electrochemical cell devices.…”

“…The resolution-of-the-identity (RI) approximation and the multi-grid approach were used in all calculations, as described in detail in our recent study. 44…”

“…In this contribution, our aim is to recommend a density functional that is accurate, efficient, and relatively fast for the theoretical prediction of the absorption electronic transitions of different organic dye sensitizers used in DSSC devices. In a recent benchmark study, we have tested 36 density functionals, including many double hybrid (DH) functionals, on a set of BODIPY based dye sensitizers, 44 and found that the spin-component-scaled double-hybrid functionals DSD-BLYP and DSD-PBEP86 perform very well, with mean absolute error (MAE) values of around 0.1 eV. 44 In the present work, we decided to extend the investigation of the TD-DFT benchmark to include other typical organic dyes that are experimentally designed to be used as light harvesting chromophores in DSSCs.…”

“…In a recent benchmark study, we have tested 36 density functionals, including many double hybrid (DH) functionals, on a set of BODIPY based dye sensitizers, 44 and found that the spin-component-scaled double-hybrid functionals DSD-BLYP and DSD-PBEP86 perform very well, with mean absolute error (MAE) values of around 0.1 eV. 44 In the present work, we decided to extend the investigation of the TD-DFT benchmark to include other typical organic dyes that are experimentally designed to be used as light harvesting chromophores in DSSCs. In fact, while there are many TD-DFT benchmark studies performed on organic dyes, 45–47 such important studies on push–pull dye sensitizers used in DSSCs are not abundant in the computational chemistry and modeling literature.…”

“…In fact, while there are many TD-DFT benchmark studies performed on organic dyes, 45–47 such important studies on push–pull dye sensitizers used in DSSCs are not abundant in the computational chemistry and modeling literature. 16,48–51 Moreover, except for the previously mentioned study, 44 the DH functionals are still not benchmarked against dye sensitizers in general and sensitizers used in DSSCs in particular. We therefore believe that this study will hopefully fill a gap in the field of computational electronic spectroscopy and materials science.…”