| 主权项 |
1. A light emitting device, wherein at least an emissive layer exists between an anode and a cathode and emits light by means of electric energy and at least an electron transporting layer exists between the emissive layer and the cathode, the emissive layer comprising a light emitting device material comprising at least one host material and at least one dopant material, wherein the at least one host material includes a member selected from the group consisting of compounds represented by formulae (H-1) and (H-2):and the at least one dopant material includes a pyrromethene compound represented by the following formula (1): wherein R1 to R4 each may be the same or different and are selected from the group consisting of hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an arylether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen, a cyano group, an amino group, a silyl group, and a ring structure formed between adjacent substituents, Ar1 to Ar5 each represent an aryl group, provided that Ar1≠Ar2 or Ar3≠Ar4, wherein ≠ means that the groups are different in structure and wherein at least one of Ar1 to Ar4 is an unsubstituted phenyl group, an unsubstituted naphthyl group, or a phenyl or naphthyl group having at least one substituent selected from the group consisting of a methyl group, a methoxy group, a tert-butyl group, and a naphthyl group; and wherein the electron transporting layer comprises a compound represented by formula (E-1): |
