Abstract: The present invention provides a light-emitting element having a structure in which the drive voltage is comparatively low and a light-emitting element in which the increase in the drive voltage over time is small. Further, the present invention provides a display device in which the drive voltage and the increase in the drive voltage over time are small and which can resist long-term use. A layer in contact with an electrode in a light-emitting element is a layer containing a P-type semiconductor or a hole-generating layer such as an organic compound layer containing a material having electron-accepting properties. The light-emitting layer is sandwiched between the hole-generating layers, and an electron-generating layer is sandwiched between the light-emitting layer and the hole-generating layer on a cathode side.

Abstract: 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.

Abstract: It is an object of the present invention to provide a light-emitting element having, between a pair of electrodes, a layer containing a light-emitting material and a transparent conductive film, wherein the electric erosion of the transparent conductive film and reflective metal can be prevented and to provide a light-emitting device using the light-emitting element. According to the present invention, a first layer 102 containing a light-emitting material, a second layer 103 containing an N-type semiconductor, a third layer 104 including a transparent conductive film, and a fourth layer 105 containing a hole-transporting medium are provided between an anode 101 and a cathode 106, wherein the first layer 102, the second layer 103, the third layer 104, the fourth layer 105, and the cathode 106 are provided in order, and wherein the cathode has a layer containing reflective metal.

Abstract: 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 with increase in film thickness. In an aspect of the invention, a light emitting element includes a first layer, a second layer and a third layer between mutually-facing first and second electrodes. The first layer is provided to be closer to the first electrode than the second layer. The third layer is provided to be closer to the second electrode than the second layer. The first layer contains a bipolar substance and a substance exhibiting an electron accepting ability with respect to the bipolar substance. The second layer contains a bipolar substance and a substance exhibiting an electron donating ability with respect to the bipolar substance. The third layer contains a light emitting substance.

Abstract: 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.

Abstract: 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 (I). 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.

Abstract: 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.

Abstract: An object is to provide a light emitting element with low drive voltage which contains an organic compound and an inorganic compound. One feature of a light emitting element of the present invention is to include a layer containing a light emitting material between a pair of electrodes, in which the layer containing a light emitting material has a layer containing a carbazole derivative represented by General Formula (1) and an inorganic compound which exhibits an electron accepting property to the carbazole derivative represented by General Formula (1). With such a structure, the inorganic compound accepts electrons from the carbazole derivative, carriers are generated internally, and a drive voltage of the light emitting element can be reduced.

Abstract: 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.

Abstract: 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.

Abstract: 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 mth light emitting layer (m is a natural number of 1?m?n) and the m+1th light emitting layer. The first and second layers are contacted to each other. The first layer contain 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.

Abstract: The present invention provides a light-emitting element having less increase in driving voltage with the accumulation of light-emission time, and provides a light-emitting element having less increase in resistance value with the increase in film thickness. A light-emitting element includes a first layer, a second layer and a third layer between a first electrode and a second electrode. The first layer is provided to be closer to the first electrode than the second layer, and the third layer is provided to be closer to the second electrode than the second layer. The first layer is a layer including an aromatic amine compound and a substance showing an electron accepting property to the aromatic amine compound. The second layer includes a substance of which an electron transporting property is stronger than a hole transporting property, and a substance showing an electron donating property to the aforementioned substance.

Abstract: 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 with increase in film thickness. In an aspect of the invention, a light emitting element includes a first layer, a second layer and a third layer between mutually-facing first and second electrodes. The first layer is provided to be closer to the first electrode than the second layer. The third layer is provided to be closer to the second electrode than the second layer. The first layer contains a bipolar substance and a substance exhibiting an electron accepting ability with respect to the bipolar substance. The second layer contains a bipolar substance and a substance exhibiting an electron donating ability with respect to the bipolar substance. The third layer contains a light emitting substance.

Abstract: 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.

Abstract: 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.

Abstract: The present invention provides a light-emitting element having less increase in driving voltage with the accumulation of light-emission time, and provides a light-emitting element having less increase in resistance value with the increase in film thickness. A light-emitting element includes a first layer, a second layer and a third layer between a first electrode and a second electrode. The first layer is provided to be closer to the first electrode than the second layer, and the third layer is provided to be closer to the second electrode than the second layer. The first layer is a layer including an aromatic amine compound and a substance showing an electron accepting property to the aromatic amine compound. The second layer includes a substance of which an electron transporting property is stronger than a hole transporting property, and a substance showing an electron donating property to the aforementioned substance.

Abstract: 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 with increase in film thickness. In an aspect of the invention, a light emitting element includes first, second and layers between mutually-facing first and second electrodes. The first layer is provided to be closer to the first electrode than the second layer. The third layer is provided to be closer to the second electrode than the second layer. The first layer contains a bipolar substance and a substance exhibiting an electron accepting ability with respect to the bipolar substance. The second layer contains a bipolar substance and a substance exhibiting an electron donating ability with respect to the bipolar substance. The third layer contains a light emitting substance.

Abstract: 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.

Abstract: An object of the invention is to provide a highly reliable light emitting element with low drive voltage and longer life than a conventional light emitting element, and a display device using the light emitting element. 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.

Abstract: 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.