TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The optically inert atom or molecule or parts of the optically inert molecule exhibits a spin-orbit coupling constant of greater than 1000 cm-1, preferably greater than 4000 cm-1. The optically inert atom or molecule in the emission range and/or in the highest occupied molecular orbital/lowest unoccupied molecular orbital-range of the organic molecule exhibits no absorption or emission. The optically inert atom or molecule comprises krypton- and xenon noble gases, bromine-containing substances, iodine-containing substances, metal atoms, metal nanoparticles, metal ions or gadolinium complexes. The composition at 300 K, exhibits a measured emission quantum yield of at least 30%, preferably greater than 90%. Krypton or xenon are used as an inert atom in the form a gas under normal pressure up to 2000 kPa.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The organic molecule in the composition exhibits delta E(S1-T1)-value between the lowest excited singlet and the underlying triplet state of less than 1500 cm-1, preferably less than 1000 cm-1. The organic molecule exhibits at least a conjugated organic group comprising aromatic, heteroaromatic or conjugated double bonds, at least one chemically-bonded donor groups with electron-donating effect, and at least one chemically bonded acceptor group with electron-withdrawing effect. The organic molecule exhibits no metal atom or metal ion. The organic hydrocarbon molecule is of formula (D1-B1-A) (I), (II) or (D1-B1-C-B1-A) (III). The numerical ratio between the organic molecules and the optically inert atoms or the molecules is 1:0.2-1:3, preferably 1:1. The organic molecule at 300 K, exhibits an emission decay time of less than 5 microseconds, preferably less than 500 nanoseconds.D1 = chemical group or substituent with single, dual or multi-electron-donating property;A = chemical group or substituent with single, dual or multi-electron electron-withdrawing property;B1 = basic structure made of conjugated organic groups of aromatic, heteroaromatic or conjugated double bonds; andC = group connected to B1, preferably chemically bonded alkenyl with less than 10 conjugated double bonds. EXAMPLE - No suitable example given.