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

Abstract: 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 π spacer order influence the performance of the dye. Key parameters associate with the short-circuit current density (J sc) and open-circuit photovoltage (V oc), including light-harvesting efficiency LHE, electron injection driving force ΔG inject, total reorganization energy λ total (λ h and λ e), the vertical dipole moment μ normal, the energy differences eV oc between E LUMO 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. [Copyright &y& Elsevier]