简介 |
PROBLEM TO BE SOLVED : To obtain an LED element having high emission intensity and a long life.
SOLUTION : The LED element is equipped with a luminescent medium containing a rare earth complex with a compound represented by formula (1) (X and Y are each the same or different atom selected from the group consisting of O, S and Se; R1, R2, R3, R4, R5 and R6 are each selected from the group consisting of a ≤20 straight-chain or branched-chain structure-containing alkyl group, alkoxy group, phenyl group, biphenyl group, naphthyl group, heterocyclic group and their substituted groups and R1 and R6 are not the same; n is an integer of ≥2 and ≤20; Z and W are each selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom and an alkyl group and the same or different) as a ligand. |