Phosphorescent material and electroluminescent device using thereof

A phosphorescent light emitting material, the material is a complex compound comprises a beta-diketonate ligand, a sulfoxide ligand and a triple charge rare earth group metal ion, the phosphorescent light emitting material has a following structure : wherein M is a triple charge rare earth group metal ion, R2 is hydrogen, R1 and R3 are selected from the group consisting of, hydrogen, C1 to C8 straight chain alkyl groups, C3 to C8 branch chain alkyl groups, heterocyclic groups and C6 to C14 aryl groups, and R4 and R5 are selected from the group consisting of substituted alkyl group, an unsubstituted alkyl group, an aryl group and a heterocyclic group.