An OLED device comprises a light-emitting layer containing a hydrocarbon host material and a light-emitting material of Formula (1): ##STR00001## wherein: each Ar represents an independently selected aromatic group; each R.sup.1 represents an independently selected alkyl group or aromatic group; n is 1 or 2; Z.sup.a represents the atoms necessary to form an aromatic ring group; R represents hydrogen or a substituent group; Z represents hydrogen or a substituent group; and L.sup.1 and L.sup.2 represent independently selected substituent groups; provided that any two adjacent substituents of any of the above groups may join to form a ring.