Light emitting device and electronic appliance using the same

摘要

The light emitting element includes a first electrode and a second electrode, between which a light emitting layer, a hole transporting layer provide in contact with the light emitting layer, an electron transporting layer provided in contact with the light emitting layer, and a mixed layer provided between the electron transporting layer and the second electrode. The mixed layer includes an electron transporting substance and a substance showing an electron donating property with respect to the electron transporting substance. The light emitting layer includes an organometallic complex represented in General Formula (1) and a host. R1 and R2 each represent an electron-withdrawing substituent group. R3 and R4 each represent any of hydrogen or an alkyl group having 1 to 4 carbon atoms. L represents any of a monoanionic ligand having a beta-diketone structure, a monoanionic bidentate chelating ligand having a carboxyl group, or a monoanionic bidentate chelating ligand having a phenolic hydroxyl group.;

主权项

1. A light emitting device comprising:
a light emitting layer between a first electrode and a second electrode; a hole transporting layer between the first electrode and the light emitting layer; an electron transporting layer between the second electrode and the light emitting layer; and a mixed layer comprising an electron transporting material and an electron donating material between the electron transporting layer and the second electrode, wherein the mixed layer is separated from the light emitting layer by the electron transporting layer interposed therebetween, wherein the electron transporting layer includes a same material as the electron transporting material in the mixed layer, and wherein the light emitting layer comprises a host material and an organometallic complex, the organometallic complex comprising: an iridium metal; a first ligand and a second ligand, each comprising: a first ring comprising a first nitrogen, a second nitrogen, and a first to fourth carbon, wherein the first nitrogen binds with the first carbon and the fourth carbon, the second nitrogen binds with the second carbon and the third carbon, the first carbon binds with the second carbon, and the third carbon binds with the fourth carbon; a second ring comprising a first to sixth carbon, wherein the first carbon binds with the second carbon and the sixth carbon, the fourth carbon binds with the third carbon and the fifth carbon, the second carbon binds with the third carbon, the fifth carbon binds with the sixth carbon, and the third carbon, the fifth carbon, and the sixth carbon bind with a first to third hydrogen, respectively; a third ring comprising a first to sixth carbon, wherein the first carbon binds with the second carbon and the sixth carbon, the fourth carbon binds with the third carbon and the fifth carbon, the second carbon binds with the third carbon, the fifth carbon binds with the sixth carbon, and the second carbon, the third carbon, the fifth carbon, and the sixth carbon bind with a first to fourth hydrogen, respectively; wherein the first ring is a hetero aromatic ring, and wherein each of the second ring and the third ring is an aromatic ring, R1 representing an electron-drawing group; R2 representing an electron-drawing group; R3 representing any one of a hydrogen and an alkyl group having 1 to 4 carbon atoms; and R4 representing any one of a hydrogen and an alkyl group having 1 to 4 carbon atoms, wherein the first carbon of the first ring binds with the first carbon of the second ring, wherein the second carbon of the first ring binds with the first carbon of the third ring, wherein the R1 binds with the fourth carbon of the third ring, wherein the R2 binds with the fourth carbon of the second ring, wherein the R3 binds with the third carbon of the first ring, and wherein the R4 binds with the fourth carbon of the first ring; and L representing a monoanionic ligand, wherein the first ligand, the second ligand, and the L are bound to the iridium metal between the iridium metal and the first nitrogen of the first ring and the second carbon of the second ring of the first ligand, the first nitrogen of the first ring and the second carbon of the second ring of the second ligand, and the L to form the organometallic complex.