On the Role of a Polymer Matrix in Enhancing Energy Transfer Efficiency Using Coumarin 6 and Rhodamine B as Donor and Acceptor Pairs

Abstract This study investigates the critical role of polymer matrices in optimizing luminescence and energy transfer, utilizing the commercial dyes Coumarin 6 (C6) and Rhodamine B (RhB) as a donor‐acceptor pair. Solution‐phase experiments revealed a dependence of energy transfer efficiency on solvent dielectric constant. Furthermore, embedding the dyes within Poly(methyl methacrylate) (PMMA) or Poly(vinyl butyral) (PVB) matrices significantly enhance energy transfer due to increased molecular proximity. A modified approach for calculating the overlap integral J(λ) was employed to analyze energy transfer in the solid state, providing insights beyond traditional Förster‐type calculations. Photostability studies demonstrated superior performance of PVB films compared to PMMA films under exposure to monochromatic (405 nm, 515 nm) and white light irradiation. Finally, a proof‐of‐concept device was developed to harness this enhanced energy transfer for light‐to‐electricity conversion, achieving a maximum efficiency of 7.28 %.