LIGHT EMITTING ELEMENT

• US 20130105787A1
• Filed: 06/24/2011
• Published: 05/02/2013
• Est. Priority Date: 07/13/2010
• Status: Abandoned Application

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Tominaga, Tsuyoshi, Tanaka, Daisaku, Matsuki, Shinichi
• Application Number:
  US13/809,798
• Publication Number:
  US 20130105787A1
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: C07D 209/86 with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the ring system
• CPC Class Codes: H10K 2101/40 Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole

Abstract

Provided is an organic thin film light emitting element which has achieved all of improved luminous efficiency, improved driving voltage and improved durability life. Specifically provided is a light emitting element which comprises a hole transport layer and an electron transport layer between a positive electrode and a negative electrode and emits light by means of electrical energy. The light emitting element is characterized in that: the hole transport layer of the light emitting element contains a compound represented by general formula (1); the electron transport layer contains a donor compound; and the donor compound is an alkali metal, an inorganic salt containing an alkali metal, a complex of an alkali metal and an organic substance, an alkaline earth metal, an inorganic salt containing an alkaline earth metal, or a complex of an alkaline earth metal and an organic substance. (In the formula, R¹-R²⁰ each represents one group selected from the group consisting of hydrogen, deuterium, an alkyl group, a cycloalkyl group, an amino group, an aryl group, a heterocyclic group, a heteroaryl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, analkoxy group, an alkylthio group, an arylether group, an arylthioether group, a halogen, a cyano group, a —P(═O)R²⁴R²⁵ group and a silyl group; R²⁴ and R²⁵ each represents an aryl group or a heteroaryl group; and these substituents may be further substituted, or adjacent two substituents may combine together to form a ring. Meanwhile, R²¹-R²³ may be the same or different and each represents one group selected from the group consisting of an alkyl group, a cycloalkyl group, an aryl group and a heteroaryl group; and these substituents maybe further substituted.)

Claims

1. A light-emitting element for emitting light by means of electric energy, in which at least a hole transport layer and an electron transport layer exist between an anode and a cathode, wherein the hole transport layer of the light-emitting element contains a compound represented by the following general formula (1), while the electron transport layer contains a donor compound, the donor compound being an alkali metal, an inorganic salt containing an alkali metal, a complex comprising an alkali metal and an organic substance, an alkaline earth metal, an inorganic salt containing an alkaline earth metal or a complex comprising an alkaline earth metal and an organic substance.

2. A light-emitting element, according to claim 1, wherein a hole injection layer exists between the hole transport layer and the anode and consists of an acceptor compound alone or contains an acceptor compound

3. A light-emitting element, according to claim 2, wherein the acceptor compound is a metal oxide or a cyano group-containing compound.

4. A light-emitting element, according to any one of claims 1 through 3, wherein the electron transport layer contains a phenanthroline derivative.

5. A light-emitting element, according to any one of claims 1 through 3, wherein the electron transport layer contains a compound having a pyrene skeleton or anthracene skeleton.

6. A light-emitting element, according to claim 5, wherein the compound having a pyrene skeleton or anthracene skeleton has a heteroaryl ring structure containing an electron-acceptable nitrogen.