Direct visualization of the charge transfer state dynamics in dilute-donor organic photovoltaic blends.

ABSTRACT: The interconversion dynamics between charge transfer state charges (CTCs) and separated charges (SCs) is still an unresolved issue in the field of organic photovoltaics. Here, a transient absorption spectroscopy (TAS) study of a thermally evaporated small-molecule:fullerene system (α6T:C₆₀) in different morphologies (dilute intermixed and phase separated) is presented. Spectral decomposition reveals two charge species with distinct absorption characteristics and different dynamics. Using time-dependent density functional theory, these species are identified as CTCs and SCs, where the spectral differences arise from broken symmetry in the charge transfer state that turns forbidden transitions into allowed ones. Based on this assignment, a kinetic model is formulated allowing the

SUBMITTER: Moore GJ 

PROVIDER: S-EPMC11561185 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature