Monomer-excimer mixed fluorescence decays in the phasor space

• Type: Article in International Scientific Journal
• Date: 2017

Authors

Martelo, L (Author) Other; Fedorov, A (Author) Other; Berberan Santos, MN (Author) Other

Journal

Title: Journal of Luminescence

Vol. 192

Pages: 64-70

ISSN: 0022-2313

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 2 Citations

Other information

Authenticus ID: P-00N-4G9

DOI: 10.1016/j.jlumin.2017.06.026

Abstract (EN): Phasor plots (plots of the Fourier sine transform vs. the Fourier cosine transform, for one or several angular frequencies) of the fluorescence intensity decay are being increasingly used in studies of homogeneous and heterogeneous systems. In this work, the phasor approach is applied to monomer-excimer systems with a focus on mixed decays, i.e. decays with both monomer and excimer contributions. The phasors of mixed decays fall on a straight line delimited by the excimer and monomer phasors. With a fixed concentration, and by continuously increasing the emission wavelength, the phasor moves from pure monomer to pure excimer. M a certain intermediate wavelength, which is concentration-dependent, the phasor crosses the universal semicircle and the decay becomes single exponential. This is an interesting case of an exponential decay not corresponding to a single fluorescent species. All results are demonstrated experimentally with pyrene in methylcyclohexane at room temperature, for which a full phasor picture emerges, combining in a single diagram monomer, excimer and mixed decays measured at several concentrations, showing the graphical power of the phasor approach.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7