excimer-luminescence 

in luminescence quenching
https://doi.org/10.1351/goldbook.E02244
An effect accompanying concentration quenching in some cases, namely the formation of a new bimolecular species which is capable of emission (excimer- and exciplex-luminescence).
Source:
PAC, 1984, 56, 231. (Nomenclature, symbols, units and their usage in spectrochemical analysis-Part VI: molecular luminescence spectroscopy) on page 235 [Terms] [Paper]