Understanding Local‐Field Correction Factors in the Framework of the Onsager−Böttcher Model

• Published in: Chemphyschem 2019-02, Vol.20 (3), p.345-355
• Main Authors: Aubret, Antoine, Orrit, Michel, Kulzer, Florian
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Electric fields; Emitters; empty/virtual cavity model; Engineering Sciences; fluorescence lifetimes in dielectrics; local-field correction; nano-probes; Optical properties; Physics
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201800923

The determination of the appropriate local‐field factor for quantifying the response of a molecule to an external electric field is of major importance in optical spectroscopy. Although numerous studies have dealt with the evolution of the optical properties of emitters as a function of their environment, the choice of the model used to quantify local fields is still ambiguous, and sometimes even arbitrary. In this paper, we review the Onsager–Böttcher model, which introduces the polarizability of the probe molecule as the determinant parameter for the local field factor, and we establish a simple conceptual framework encompassing all commonly used models. Finally, a discussion of published experimental research illustrates the potential of the measurement of local electric fields in dense dielectric media, as well as the subtleties involved in their interpretation. Single molecules and other nano‐particles can serve as sensitive probes for condensed matter. A potential complication in the interpretation of such experiments is the field‐correction factor needed to relate the local field (experienced by the probe) to its macroscopic counterpart. We review a simple conceptual framework encompassing all commonly used models for obtaining local‐field factors, and we discuss experimental research that illustrates the potential of the measurement of local electric fields in dense dielectric media.