Density functional theory characterization and verification of high-performance indoline dyes with D-A-π-A architecture for dye-sensitized solar cells

摘要

Six indoline-based dyes 1-6 used in DSSCs with difference in π spacer were theoretically researched and verified using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) to shed light on how the additional (auxiliary) acceptor and it spacer order influence the performance of the dye. Key parameters associate with the short-circuit current density (J_(sc)) and open-circuit photo-voltage (V_(oc)), including light-harvesting efficiency LHE, electron injection driving force ΔG~(lnject), total reorganization energy λ_(totai) (λ_h and λ_e), the vertical dipole moment μ_(normal). the energy differences eV_(oc) between Elumo and E_(cb) as well as the extent of electron recombination were characterized. The theoretical results reveal that compared with dye 1, dyes 2—6 improve the performance potentially due to their auxiliary acceptor. These enable us to determine these factors related to the J_(Sc) and V_(oc) can be significantly influenced by the incorporated electron-withdrawing subunit into molecular backbone.