How Does Light Scattering Affect luminescence?

M. GABRIELA LAGORIO AND ENRIQUE SAN ROMÁN

JOURNAL OF CHEMICAL EDUCATION

American Chemical Society

Lugar: Wisconsin; Año: 2002 vol. 79 p. 1362 - 1367

0021-9584

Many articles connected with the topic of molecular fluorescence in solution have been published in the educational literature. Helpful papers for teaching purposes may be found in this Journal (1?6). However, no information about spectral analysis and quantum yield determinations in the presence of light scattering is found. This situation usually appears when dealing with most solid materials. Despite the increasing importance that the luminescence of solids has in our daily life (in textiles, printings, paints, etc.), it usually remains unclear how to elucidate fluorescence data from such systems. As a general rule, students are far more familiar with solution physical chemistry than with solid-state physical chemistry. Concerning photochemistry, this probably results from the complexity that arises when light scattering is introduced. This article attempts to fill this vacancy by explaining how to work with such systems and showing quantitative corrections to account for light re-absorption and re-emission processes. For didactical reasons we present the approach for scattering media compared to the well-known treatment for non-scattering materials. This presentation is suitable for a graduate-level course in fluorescence as well as for a spectroscopy course for undergraduate students in the last year of their university study. Experimental details for obtaining true emission and excitation spectra are presented. Frequent artifacts and misinterpretations are also discussed. The analysis follows closely a treatment developed in our laboratory (7). scattering media compared to the well-known treatment for non-scattering materials. This presentation is suitable for a graduate-level course in fluorescence as well as for a spectroscopy course for undergraduate students in the last year of their university study. Experimental details for obtaining true emission and excitation spectra are presented. Frequent artifacts and misinterpretations are also discussed. The analysis follows closely a treatment developed in our laboratory (7). Journal (1?6). However, no information about spectral analysis and quantum yield determinations in the presence of light scattering is found. This situation usually appears when dealing with most solid materials. Despite the increasing importance that the luminescence of solids has in our daily life (in textiles, printings, paints, etc.), it usually remains unclear how to elucidate fluorescence data from such systems. As a general rule, students are far more familiar with solution physical chemistry than with solid-state physical chemistry. Concerning photochemistry, this probably results from the complexity that arises when light scattering is introduced. This article attempts to fill this vacancy by explaining how to work with such systems and showing quantitative corrections to account for light re-absorption and re-emission processes. For didactical reasons we present the approach for scattering media compared to the well-known treatment for non-scattering materials. This presentation is suitable for a graduate-level course in fluorescence as well as for a spectroscopy course for undergraduate students in the last year of their university study. Experimental details for obtaining true emission and excitation spectra are presented. Frequent artifacts and misinterpretations are also discussed. The analysis follows closely a treatment developed in our laboratory (7). scattering media compared to the well-known treatment for non-scattering materials. This presentation is suitable for a graduate-level course in fluorescence as well as for a spectroscopy course for undergraduate students in the last year of their university study. Experimental details for obtaining true emission and excitation spectra are presented. Frequent artifacts and misinterpretations are also discussed. The analysis follows closely a treatment developed in our laboratory (7).