Pioneer Electronic Corporation

Teruichi Watanabe

Kenichi Nagayama

Tohru Namiki

Hitoshi Sato

Masanao Shinkai

Hitoshi Satoh

An organic electroluminescent device comprises an anode, a positive-hole transport layer made of an organic compound, an emitting layer made of an organic compound, and a cathode which are layered in sequence, further comprising an electron-injecting layer containing at least one of alkaline earth metal oxides and disposed between the emitting layer and the cathode. This device emits light at a high luminance and a high efficiency upon application of a low voltage together with reduction of the decrement of luminance in the running of emitting light of the device. Selection scope for cathode materials is expanded because of the device is free from the restriction of a low work function for the cathode layer. The cathode can be made a transparent electrode such as ITO. Anode and cathode lines may be formed with low resistance material. As a result, emitting efficiency and life time of the device is improved.

Organic electroluminescent device

Disclosed are organic EL elements having high environmental stability as well as high luminous efficiency and luminance. In an organic EL element comprising a transparent anode, a hole-carrying layer, a light-emitting layer and an alloy cathode consisting of a first metal Li and a stabilizing second metal Al, all laminated on a substrate, the concentration of the first metal Li contained in the alloy region with a predetermined thickness from the interface between the alloy cathode and the organic layer is controlled to a minute amount ranging from 0.005 wt. % to 0.3 wt. %. In another organic EL element comprising a transparent anode, a hole-carrying layer, a light-emitting layer and an alloy cathode consisting of a first metal Sr and a stabilizing second metal Mg, all laminated on a substrate, the concentration of the first metal Sr contained in the alloy region with a predetermined thickness from the interface between the alloy cathode and the organic layer (light-emitting layer or electron-carrying layer) is controlled to a minute amount ranging from 10 wt. % to 40 wt. %.

Organic electroluminescent element

An organic electroluminescent device comprises a cathode, an emitting layer of organic compound including a quinoline derivative, a positive-hole transport layer of organic compound and an anode which are laminated in sequence, further comprising a metal film having a work function equal to or lower than that of the anode and partially disposed between the anode and the positive-hole transport layer. This device achieves a high luminance efficiency per se. The existence of the metal film reduces resistance values of whole anodes. The entering efficiency of the positive-hole carrier is partially decreased due to the metal film line. This metal film line decreases the waste electric current that does not contribute the emission of the emitting layer.

Disclosed is an organic electroluminescent display apparatus that has small panels each constituted by forming light-emitting sections, each comprising an organic electroluminescent layer, a transparent electrode and a metal electrode, on one major surface of the substrate. The transparent electrode has an extending portion formed to continuously extend from one major surface of the substrate to one side surface. The associated transparent electrodes of adjoining small panels are electrically connected via an anisotropic conductive sheet which has a conductivity only in the thickness direction. This design can narrow the non-light emitting area of each joint of the small panels.

Growing community of inventors

Tsurugashima, Japan

Teruichi Watanabe