| abstract |
A light-emitting composition comprises a polymer and a phosphorescent light-emitting material wherein the polymer comprises conjugating repeat units of formula (I) and up to 20 mol % of conjugation-blocking repeat units of repeat units of formula (II): wherein Ar 1 represents an aryl or heteroaryl group; R 1 , which may be the same or different in each occurrence, is a substituent; p is 0, 1, 2, 3 or 4; Ar 2 in each occurrence independently represents a substituted or unsubstituted aryl or heteroaryl group; and Sp 1 represents an acyclic spacer group that does not provide any conjugation path between the two groups Ar 2 . Preferably, Ar 1 is unsubstituted or substituted with one or more C 1-30 hydrocarbyl substituents. |