self-absorption effect in luminescence spectroscopy

https://dx.doi.org/10.1351/goldbook.S05580
The reabsorption of luminescence by the analyte and interfering impurities within the excitation volume.
Source:
PAC, 1984, 56, 231 (Nomenclature, symbols, units and their usage in spectrochemical analysis-Part VI: molecular luminescence spectroscopy) on page 244