Light-emitting element and light-emitting device

Abstract

Organic materials doped with an alkali metal have been conventionally used for electron-transporting layers or electron injection layers which constitute light-emitting films in organic EL light-emitting elements which are used in displays or illuminating devices. Such conventional organic materials involve problems such that a strict process control is required since the alkali metal is highly reactive and thus likely to be formed into a hydroxide, such that the resulting light-emitting element or light-emitting device needs complete sealing, and such that life of the light-emitting element cannot be sufficiently long. The present invention uses an alkali metal-containing fullerene or an organic material doped with an alkali metal-containing fullerene for electron-transporting layers or electron injection layers which constitute light-emitting films in organic EL light-emitting elements. The alkali metal-containing fullerene or the organic material doped with an alkali metal-containing fullerene is not very reactive with moisture in the atmosphere or other impurities and thus the process control thereof is easy. Furthermore, even with a simple sealing structure, the resulting light-emitting element can have sufficiently long life.

Description

technical field [0001] The present invention relates to a light-emitting element and a light-emitting device using organic EL as a light-emitting material used in devices such as display devices and lighting devices. Background technique [0002] Non-Patent Document 1: AMD Application Note Vol. 1 (2002, December) P1-P19, About Alkali Metal Diffusion of OLEDs (AMD Application Note Vol. 1 Dec., 2002, P1-19, AlkaliMetal Dispenser for OLED). [0003] Patent Document 1: Japanese Unexamined Patent Publication No. 2001-6878, thin-film EL element and its driving method. [0004] Currently, various display devices such as liquid crystal displays and plasma displays featuring thin and flat panels are widely used as display devices replacing picture tubes. In addition, in recent years, the research and development of display devices using organic EL has been rapidly progressing, and this research has attracted attention as a strong candidate for next-generation display devices. Organ...

AI Technical Summary

Problems solved by technology

[0006] However, organic materials doped with alkali metals (used in the electron transport layer and electron injection layer) have the problem of high reactivity of alkali metals and easy formation of hydroxides.

Therefore, there are the following problems: in the manufacturing process of the light-emitting element, it must be strictly controlled to avoid the reaction of the organic material or the formed film doped with alkali metal with the water molecules and other impurities in the atmosphere; the light-emitting element or light-emitting device must be Completely sealed to avoid leakage of outside gas into the manufactured light-emitting element, reaction with water vapor, etc.

However, the electron affinity of cavity fullerene is small, and the electron injection efficiency is poor, so there is a problem of low luminous efficiency.

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