Electroluminescent device comprising in this order

(a) an anode

(b) a hole transporting layer

(c) a light-emitting layer

(d) optionally an electron transporting layer and

(e) a cathode

and a light-emitting substance, wherein the light-emitting substance is a diketopyrrolopyrrole represented by formula I or formula III ##STR1##

processes for the preparation of compounds I, its uses and compositions comprising the compounds I and/or III.