LIGHT EMITTING MATERIAL, COMPOSITION AND DEVICE

摘要

A light-emitting composition comprises a first fluorescent organic emitter and a phosphorescent organic emitter. The first fluorescent organic emitter has a peak wavelength in the range of 490-560 nm and a triplet excited state energy level is higher than a triplet excited state energy level of the phosphorescent organic emitter. The first fluorescent emitter is preferably selected from compounds of formulae (la)-(Id): wherein each Ar independently represents an aryl or heteroaryl group, R represents H or a substituent and wherein any of the rings of formulae (la) - (Id), including any ring of any Ar group, are unsubstituted or independently substituted with one or more substituents.