Table 2. General Photoluminescent Properties of Organic and Inorganic Species^a.

	organic	inorganic
	e.g. perylenes, coumarins, rhodamines, and quinolines.	e.g. metal complexes and rare earth metal oxides.
photoluminescent quantum yield	variable, but generally high; highly dependent upon the solvent/environment	variable, but generally quite low
molar absorbance	variable, but generally high	variable, depending on ligand structure
emission spectra	broad, around 40–70 nm half-width	narrow, around 10 nm half-width
stokes shift	variable, commonly around 10–100 nm	quite large, around 100–200 nm
photoluminescent lifetime	short, around 0.5–5 ns	long, can be up to 1 ms
photostability	variable, but generally poor	relatively high
toxicity	variable, but often low	less definitive data available, can be quite high

^aAdapted with permission from ref (41). Copyright 2009 Springer.