An electroluminescent device includes a light-emitting layer containing a host material and: (a) a compound of Formula (1): X.sup.1--Ar.sup.1--C(R.sub.1).dbd.C(R.sub.2)--Ar.sup.2 (1) wherein: Ar.sup.1 represents a divalent aromatic group; Ar.sup.2 represents an aromatic group; X.sup.1 represents at least one electron-donating group; R.sub.1 and R.sub.2 independently represent hydrogen or a substituent; and (b) a light-emitting boron complex having an absorption spectrum that overlaps with the emission spectrum of compound (1). The device serves to improve luminance efficiency while maintaining good color purity.