Quantifying the Contributions of Inner-Filter, Re-Absorption and Aggregation Effects in the Photoluminescence of High-Concentration Conjugated Polymer Solutions

Abstract

The optical properties of high-concentration solutions of conjugated molecules are dominated by inner-filter and re-absorption effects. We apply a simple model to isolate the contributions from these phenomena to the non-linearity of the observed photoluminescence (PL) intensity with concentration. Poly(9,9-dioctylflourene) (PFO) solutions were studied across a range of concentrations and in a number of different solvents. The model accurately predicts the behaviour of PFO in good solvents up to concentrations above 0.1 mg/ml. In solutions of PFO in poor solvents and at high concentrations where we find a significant amount of β-phase PFO present the model is less accurate. We attribute the difference between predicted PL behaviour and that observed to non-radiative energy transfer from the bulk “glassy” phase PFO to the β-phase PFO.

Publication
Journal of Luminescence
Silvia Giordani
Silvia Giordani
Full Professor Chair of Nanomaterials

My research interests are in the design, synthesis, and characterization of hybrid smart nanomaterials for biomedical, energy and environmental applications