Compound for organic electroluminescent device and organic electroluminescent device using the same

Abstract

Disclosed is an organic electroluminescent device (organic EL device) which has improved luminous efficiency, sufficient driving stability and a simple structure. The organic EL device comprises a light-emitting layer between an anode and a cathode arranged on a substrate, and the light-emitting layer contains a phosphorescent dopant and a host material composed of a compound represented by formula (1) which has a carbazolyl group at each end. In the formula (1), each X independently represents an optionally substituted CH or N, and each L represents a direct bond, an ethylene group or an acetylene group.

Description

technical field The present invention relates to a compound for an organic electroluminescence element and an organic electroluminescence element using the same. Specifically, it relates to a thin-film device that emits light by applying an electric field to a light-emitting layer containing an organic compound. Background technique In general, an organic electroluminescence element (hereinafter referred to as an organic EL element) is composed of a light emitting layer and a pair of opposing electrodes sandwiching the layer as its simplest structure. That is, in the organic EL element, when an electric field is applied between both electrodes, electrons are injected from the cathode and holes are injected from the anode, and these recombine in the light-emitting layer to emit light. In recent years, development of organic EL elements using organic thin films has been advanced. In particular, in order to improve luminous efficiency, by optimizing the type of electrodes for...

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Problems solved by technology

However, the above-mentioned compound has high triplet excitation energy by having two o-carbazolylphenyl groups at the terminal, so the luminous efficiency is improved. , a large deformation occurs in the molecule, and in the case of electro-oxidation and reduction, it is difficult to generate non-localization between the aromatic rings, and excessive addition to the molecule is required, and the durability is not sufficient

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