A method of forming an electroluminescent device comprising the steps of: providing a substrate comprising a first electrode for injecting charge carriers of a first type; forming an electroluminescent layer having a surface by depositing onto the substrate a composition comprising a host material and a light-emitting dopant monomer of formula (I): A-C--(X).sub.n (I) wherein X represents a polymerisable group; A represents a light-emitting group; C represents a bond or a spacer group and n is an integer; rendering at least some of the electroluminescent layer insoluble in a solvent by polymerising the monomer of formula (I); exposing the electroluminescent layer to the solvent; and depositing a second electrode capable of injecting charge carriers of a second type over the electroluminescent layer.