Recently I red an article "Surface Enhanced Fluorescence". It is a topical review by Emmanuel Fort and Samuel Gresillon. Here it is: http://turroserver.chem.columbia.edu/surfaceplasmons/pdf/53_JPD_41_1_2008_SEFSRev.pdf
On the 8th page of pdf there's such thing stated:
The energy is transferred to electron–hole pairs of the metal (excitons) which act as energy acceptors.
How is it possible? I was searching for knowledge about excitons and it seems that they can't exist in metals. Even princeton says so: https://www.princeton.edu/~achaney/tmve/wiki100k/docs/Exciton.html Not a single word about metals.
So... can I treat this article seriously? Or maybe there's something I'm missing? Can an exciton exist in metal?