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

Abstract

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 Δ G 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.