Effect of Length of Ethylene Glycol Sigma-Linkers on Triphenylamine-Based Dimers Used As Molecular Donors for Organic Solar Cells

The direct comparison of two push-pull based dimers prepared in only three steps from commercially and affordable building blocks is reported herein. Built around similar absorbing units, two ethylene glycol sigma-connectors of different lengths were used to investigate, and rationalize, their impact on the optical, self-assembly and therefore photovoltaic properties. With significant differences from the charge transport, morphology and therefore power conversion efficiencies, results gathered in this study emphasized the potential of such simple yet efficient strategy to fine tune the processability of an active compound. Two push-pull based dimers, built around similar absorbing units and linked by two ethylene glycol sigma-connectors of different lengths are reported herein. Effects on the optical, self-assembly and therefore photovoltaic properties are rationalized, highlighting significant differences from the charge transport, morphology of the active layers and therefore power conversion efficiencies.image