Semiconductor Energy Laboratory Co., Ltd.

Oki Electric Industry Co., Ltd.

Oki Semiconductor Co., Ltd.

Daisuke Kumaki

Satoshi Seo

Hisao Ikeda

Junichiro Sakata

Harue Nakashima

Ryoji Nomura

Hiroko Abe

Sachiko Kawakami

Yuji Iwaki

Tetsuo Tsutsui

Kumi Kojima

Shunpei Yamazaki

Hideko Inoue

Satoko Shitagaki

Takako Takasu

Yuji c/o Semiconductor Energy Laboratory Co Ltd Iwaki

Satoshi c/o Semiconductor Energy Laboratory Co Ltd Seo

Hisao Semiconductor Energy Laboratory Co Ikeda

Junichiro Semiconductor Energy Lab Co Sakata

Satoshi Semiconductor Energy Laboratory Co Seo

Satoshi c/oSemiconductor Energy Lab Co Ltd Seo

Satoshi Semiconductor Energy Lab Co Ltd Seo

Satoshi c/o Semicond Energy LabCoLtd Seo

In the present invention, a light-emitting element operating at low driving voltage, consuming low power, emitting light with good color purity and manufactured in high yields can be obtained. A light-emitting element is disclosed with a configuration composed of a first layer containing a light-emitting material, a second layer, a third layer are formed sequentially over an anode to be interposed between the anode and a cathode in such a way that the third layer is formed to be in contact with the cathode. The second layer is made from n-type semiconductor, a mixture including that, or a mixture of an organic compound having a carrier transporting property and a material having a high electron donor property. The third layer is made from p-type semiconductor, a mixture including that, or a mixture of an organic compound having a carrier transporting property and a material having a high electron acceptor property.

Light-emitting element

It is an object of the present invention to provide a light-emitting element having a layer containing a light-emitting material and a transparent conductive film between a pair of electrodes, in which electric erosion of the transparent conductive film and metal can be prevented, and also to provide a light-emitting device using the light-emitting element. According to one feature of the invention, a light-emitting element includes a first layercontaining a light-emitting material, a second layercontaining a material having a donor level, a third layerincluding a transparent conductive film, and a fourth layercontaining a hole-transporting medium between a first electrodeand a second electrode, in which the first layer, the second layer, the third layer, the fourth layer, and the second electrodeare provided sequentially, in which the second electrodehas a layer containing metal.

Light-emitting element and light-emitting device

An object of the present invention is to provide a light emitting element having slight increase in driving voltage with accumulation of light emitting time. Another object of the invention is to provide a light emitting element having slight increase in resistance value with increase in film thickness. A light emitting element of the invention includes a first layer for generating holes, a second layer for generating electrons and a third layer comprising a light emitting substance between first and second electrodes. The first and third layers are in contact with the first and second electrodes, respectively. The second and third layers are connected to each other so as to inject electrons generated in the second layer into the third layer when applying the voltage to the light emitting element such that a potential of the second electrode is higher than that of the first electrode.

Light emitting element and light emitting device using the same

One object of the present invention is to provide a light emitting element that includes an organic compound and an inorganic compound and has low driving voltage. The light emitting element of the invention includes a plurality of layers between a pair of electrodes, wherein the plurality of layers includes a layer that contains a carbazole derivative represented by a general formula (1) and an inorganic compound exhibiting an electron accepting property with respect to the carbazole derivative. By utilizing this structure, electrons are transported between the carbazole derivative and the inorganic compound and carriers are internally generated, and hence, the driving voltage of the light emitting element can be reduced. 

Light emitting element and light emitting device

A layer included in an electroluminescent element is required to be thickened to optimize light extraction efficiency of the electroluminescent element and to prevent short-circuit between electrodes. However, in a conventional element material, desired light extraction efficiency cannot be accomplished since drive voltage rises or power consumption is increased as the element material is thickened. A composite is formed by mixing a conjugated molecule having low ionization potential and a substance having an electron-accepting property to the conjugated molecule. A composite layer included in an element is formed using the composite as an element material. The composite layer is arranged between a first electrode and a light emitting layer or between a second electrode and a light emitting layer. The composite layer has high conductivity; therefore, drive voltage does not rise even if a film thickness is increased. Thus, an electroluminescent element which can prevent short-circuit of an electrode can be provided.

Light emitting element and electronic device using the same

A light emitting element of the invention includes n pieces of light emitting layers (n is a natural number) between first and second electrodes. A first layer and a second layer are provided between the mlight emitting layer (m is a natural number of 1&#x2266;m&#x2266;n) and the m+1light emitting layer. The first and second layers are contacted to each other. The first layer contains a substance that transports holes easily and a substance with an electron accepting property. The second layer contains a substance that transports electrons easily and a substance with an electron donating property. Molybdenum oxide is used as the substance with the electron accepting property.

An object of the present invention is to provide a composite material formed of an organic compound and an inorganic compound, and has an excellent carrier transporting property, an excellent carrier injecting property to the organic compound, as well as excellent transparency. A composite material of the present invention for achieving the above object is a composite material of an organic compound represented in the general formula below, and an inorganic compound. For the inorganic compound, an oxide of a transition metal, preferably an oxide of a metal belonging to groups 4 to 8 of the periodic table, in particular vanadium oxide, tantalum oxide, molybdenum oxide, tungsten oxide, rhenium oxide, and ruthenium oxide, can be used. 

Composite material, light emitting element and light emitting device

It is an object of the present invention to provide a material which is excellent in a hole injecting property and a hole transporting property, and to provide a light emitting element and a light emitting device using a material which is excellent in a hole injecting property and a hole transporting property. The present invention provides a carbazole derivative represented by a general formula (1). The carbazole derivative according to the present invention is excellent in the hole injecting property. By using the carbazole derivative according to the present invention as a hole injecting material for a hole injecting layer of a light emitting element, a driving voltage can be reduced. In addition, a lower driving voltage, improvement of the luminous efficiency, a longer life time, and higher reliability can be realized by applying the material to a light emitting element or a light emitting device.

Carbazole derivative, and light emitting element and light emitting device using the carbazole derivative

In the present invention, a light-emitting element operating at low driving voltage, consuming low power, emitting light with good color purity and manufactured in high yields can be obtained. A light-emitting element is disclosed with a configuration composed of a fist layer containing a light-emitting material, a second layer, a third layer are formed sequentially over an anode to be interposed between the anode and a cathode in such a way that the third layer is formed to be in contact with the cathode. The second layer is made from n-type semiconductor, a mixture including that, or a mixture of an organic compound having a carrier transporting property and a material having a high electron donor property. The third layer is made from p-type semiconductor, a mixture including that, or a mixture of an organic compound having a carrier transporting property and a material having a high electron acceptor property.

Light-emitting elements have a problem that their light-extraction efficiency is low due to scattered light or reflected light inside the light-emitting elements. The light-extraction efficiency of the light-emitting elements needs to be enhanced by a new method. According to the present invention, a light-emitting element includes a first layer generating holes, a second layer including a light-emitting layer for each emission color and a third layer generating electrons between an anode and a cathode, and the thickness of the first layer is different depending on each layer including the light-emitting layer for each emission color. A layer in which an organic compound and a metal oxide are mixed is used as the first layer, and thus, the driving voltage is not increased even when the thickness is increased, which is preferable.

Light emitting device

A light emitting element according to the invention comprises a plurality of layers which is interposed between a pair of electrodes, in which at least one of the plurality of layers is formed of a layer containing a light emitting material, and the layer containing a light emitting material is interposed between a layer containing an oxide semiconductor and/or metal oxide and a material having a higher hole transporting property than an electron transporting property, and a layer containing an oxide semiconductor and/or metal oxide, a material having a higher electron transporting property than a hole transporting property and a material which can donate electrons to the material having a higher electron transporting property than a hole transporting property.

Light emitting element and display device using the same

An object of the present invention is to provide a light emitting element or a light emitting device that can be formed without any regard for a work function of an electrode. Another object of the invention is to provide a light emitting element or a light emitting device in that the range of choice for a material of an electrode can be widened. In an aspect of the invention, a light emitting device includes first, second and third layers between mutually-facing first and second electrodes. The first layer has a donor level. The second layer is a single layer or a laminated body containing a light emitting substance. The third layer has an acceptor level. When a potential of the second electrode is set higher than that of the first electrode, holes generated in the second layer are injected in the third layer.

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Tokamachi, Japan

Daisuke Kumaki