Abstract: A novel light-emitting device that is highly convenient, useful, or reliable is provided. The light-emitting device includes a first electrode, a second electrode, a unit, and a first layer. The second electrode includes a region overlapping with the first electrode. The unit includes a region positioned between the first electrode and the second electrode. The unit includes a second layer and a third layer. The second layer includes a region where the third layer is positioned between the second layer and the first electrode. The second layer contains a light-emitting material. The first layer includes a region positioned between the third layer and the first electrode. The first layer contains a material having an acceptor property and a first material. The first layer includes a first region and a second region. The first region includes a region positioned between the second region and the first electrode. The first region contains the material having an acceptor property at a first concentration.

Abstract: Provided is a light-emitting device that can have sufficient device characteristics even with a smaller number of stacked layers in an EL layer and a thicker light-emitting layer than a conventional one by using, as an organic compound used for the EL layer of the light-emitting device, a material that can increase not only a property of carrier transport to the light-emitting layer but also a property of carrier injection from an electrode.

Abstract: A light-emitting element with a high current efficiency is provided. A low-power consumption light-emitting device is also provided. In addition, low-power consumption electronic device and lighting device are provided. The light-emitting element includes an EL layer between a pair of electrodes. The EL layer includes a light-emitting layer. The light-emitting layer includes a first light-emitting layer and a second light-emitting layer. The emission peak of the second light-emitting layer is at a shorter wavelength than that of the first light-emitting layer. The first light-emitting layer includes a host material and a guest material. The LUMO level of the guest material is in the range of ±0.1 eV of the LUMO level of the host material.

Abstract: A light-emitting element including a first electrode, a second electrode, and an EL layer provided between the first and second electrodes is provided. The first electrode includes a conductive layer, a first transparent conductive layer in contact with the conductive layer, and a second transparent conductive layer in contact with the first transparent conductive layer. The first transparent conductive layer contains a first oxide. The second transparent conductive layer contains a second oxide. The conductive layer has a function of reflecting light. The first oxide contains In and M (M represents Al, Si, Ti, Ga, Y, Zr, La, Ce, Nd, or Hf). The second oxide contains In. The resistivity of the second transparent conductive layer is lower than that of the first transparent conductive layer. The thickness of the second transparent conductive layer is greater than or equal to that of the first transparent conductive layer.

Abstract: A light-emitting element with a high current efficiency is provided. A low-power consumption light-emitting device is also provided. In addition, low-power consumption electronic device and lighting device are provided. The light-emitting element includes an EL layer between a pair of electrodes. The EL layer includes a light-emitting layer. The light-emitting layer includes a first light-emitting layer and a second light-emitting layer. The emission peak of the second light-emitting layer is at a shorter wavelength than that of the first light-emitting layer. The first light-emitting layer includes a host material and a guest material. The LUMO level of the guest material is in the range of ±0.1 eV of the LUMO level of the host material.

Abstract: A light-emitting element with a high current efficiency is provided. A low-power consumption light-emitting device is also provided. In addition, low-power consumption electronic device and lighting device are provided. The light-emitting element includes an EL layer between a pair of electrodes. The EL layer includes a light-emitting layer. The light-emitting layer includes a first light-emitting layer and a second light-emitting layer. The emission peak of the second light-emitting layer is at a shorter wavelength than that of the first light-emitting layer. The first light-emitting layer includes a host material and a guest material. The LUMO level of the guest material is in the range of ±0.1 eV of the LUMO level of the host material.

Abstract: A highly reliable light-emitting element which can keep favorable characteristics throughout long-time driving is provided. In addition, a light-emitting element with high color purity and high emission efficiency is provided. Furthermore, a light-emitting device having a long lifetime in which the light-emitting element is used is provided. Moreover, an electronic device and a lighting device each of which has a long lifetime are provided. In the light-emitting element including an EL layer between a pair of electrodes, the EL layer has a stacked-layer structure of a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer. The light-emitting layer includes an electron-transport material, a hole-transport material, and a light-emitting material. Furthermore, light emitted from the first light-emitting layer and light emitted from the third light-emitting layer have the same color and each have a longer wavelength than light emitted from the second light-emitting layer.

Abstract: A light-emitting element having high external quantum efficiency is provided. A light-emitting element having a long lifetime is provided. A light-emitting layer is provided between a pair of electrodes. The light-emitting layer is a stack of a first light-emitting layer, which contains at least a first phosphorescent compound, a first organic compound having an electron-transport property, and a second organic compound having a hole-transport property and is provided on the anode side, and a second light-emitting layer, which contains at least a second phosphorescent compound and the first organic compound having an electron-transport property. A combination of the first organic compound and the second organic compound forms an exciplex.

Abstract: A light-emitting element with high emission efficiency which includes a plurality of light-emitting layers and exhibits multi-color light emission is provided. The light-emitting element includes a first electrode, a second electrode, and an EL layer between the first electrode and the second electrode. The EL layer includes a first injection layer, a first light-emitting layer, and a second light-emitting layer in a first region, and a second injection layer, the first light-emitting layer, and the second light-emitting layer in a second region. The first light-emitting layer includes a first light-emitting material and a first host material, and the second light-emitting layer includes a second light-emitting material and a second host material. A color of light emitted from the first region is different from that of light emitted from the second region.

Abstract: To provide a novel light-emitting element or a novel light-emitting device with high emission efficiency and low power consumption, a light-emitting element having a plurality of light-emitting layers between a pair of electrodes includes a lower electrode, a first light-emitting layer over the lower electrode, a charge-generation layer over the first light-emitting layer, a second light-emitting layer over the charge-generation layer, and an upper electrode over the second light-emitting layer. An emission spectrum of the first light-emitting layer peaks at a longer wavelength than an emission spectrum of the second light-emitting layer. A distance of between a bottom surface of the upper electrode and a bottom surface of the first light-emitting layer is less than or equal to 130 nm.

Abstract: A light-emitting element having high external quantum efficiency is provided. A light-emitting element having a long lifetime is provided. A light-emitting element includes a light-emitting layer between a pair of electrodes. The light-emitting layer contains at least a phosphorescent compound, a first organic compound (host material) having an electron-transport property, and a second organic compound (assist material) having a hole-transport property. The light-emitting layer has a stacked-layer structure including a first light-emitting layer and a second light-emitting layer, and the first light-emitting layer contains a higher proportion of the second organic compound than the second light-emitting layer. In the light-emitting layer (the first light-emitting layer and the second light-emitting layer), a combination of the first organic compound and the second organic compound forms an exciplex.

Abstract: A highly reliable light-emitting element which can keep favorable characteristics throughout long-time driving is provided. In addition, a light-emitting element with high color purity and high emission efficiency is provided. Furthermore, a light-emitting device having a long lifetime in which the light-emitting element is used is provided. Moreover, an electronic device and a lighting device each of which has a long lifetime are provided. In the light-emitting element including an EL layer between a pair of electrodes, the EL layer has a stacked-layer structure of a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer. The light-emitting layer includes an electron-transport material, a hole-transport material, and a light-emitting material. Furthermore, light emitted from the first light-emitting layer and light emitted from the third light-emitting layer have the same color and each have a longer wavelength than light emitted from the second light-emitting layer.

Abstract: A light-emitting element with high reliability that can keep favorable characteristics after long-time driving is provided. In addition, a light-emitting device having a long lifetime including the light-emitting element is provided. Moreover, an electronic device and a lighting device having a long lifetime are provided. In a light-emitting element including an EL layer between a pair of electrodes, a light-emitting layer included in the EL layer has a stacked-layer structure which is different from the conventional structure, whereby the light-emitting element can keep favorable characteristics after long-time driving even in the case where carrier balance is changed over time due to driving of the light-emitting element or a light-emitting region is shifted due to the change.

Abstract: A tandem light-emitting element in which generation of crosstalk can be suppressed even when the element is applied to a high-definition display is provided. In the tandem light-emitting element, a layer in contact the anode side of an intermediate layer contains 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen).

Abstract: To provide a novel light-emitting device with high productivity, the light-emitting device includes a first light-emitting element, a second light-emitting element, and a third light-emitting element. In the first light-emitting element, a first lower electrode, a first transparent conductive layer, a first light-emitting layer, a second light-emitting layer, and an upper electrode are stacked in this order. In the second light-emitting element, a second lower electrode, a second transparent conductive layer, the first light-emitting layer, the second light-emitting layer, and the upper electrode are stacked in this order. In the third light-emitting element, a third lower electrode, a third transparent conductive layer, the second light-emitting layer, and the upper electrode are stacked in this order. The first transparent conductive layer includes a first region. The second transparent conductive layer includes a second region as thick as the third transparent conductive layer.

Abstract: A light-emitting device in which different electrodes in a work function are used in a first light-emitting element and a second light-emitting element are provided. A light-emitting device includes a first light-emitting element and a second light-emitting element. The first light-emitting element includes a first electrode, an EL layer, and a second electrode in this order. The second light-emitting element includes a third electrode, the EL layer, and the second electrode in this order. The EL layer includes a first light-emitting layer, a layer, and a second light-emitting layer in this order. The structure of the first light-emitting layer is different from the structure of the second light-emitting layer. The first light-emitting element and the second light-emitting element are different in a carrier-injection property.

Abstract: A tandem light-emitting element in which generation of crosstalk can be suppressed even when the element is applied to a high-definition display is provided. In the tandem light-emitting element, a layer in contact the anode side of an intermediate layer contains 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen).

Abstract: A light-emitting element with high emission efficiency which includes a plurality of light-emitting layers and exhibits multi-color light emission is provided. The light-emitting element includes a first electrode, a second electrode, and an EL layer between the first electrode and the second electrode. The EL layer includes a first injection layer, a first light-emitting layer, and a second light-emitting layer in a first region, and a second injection layer, the first light-emitting layer, and the second light-emitting layer in a second region. The first light-emitting layer includes a first light-emitting material and a first host material, and the second light-emitting layer includes a second light-emitting material and a second host material. A color of light emitted from the first region is different from that of light emitted from the second region.

Abstract: A light-emitting element having high external quantum efficiency is provided. A light-emitting element having a long lifetime is provided. A light-emitting layer is provided between a pair of electrodes. The light-emitting layer is a stack of a first light-emitting layer, which contains at least a first phosphorescent compound, a first organic compound having an electron-transport property, and a second organic compound having a hole-transport property and is provided on the anode side, and a second light-emitting layer, which contains at least a second phosphorescent compound and the first organic compound having an electron-transport property. A combination of the first organic compound and the second organic compound forms an exciplex.

Abstract: To provide a light-emitting element with low drive voltage. The light-emitting element includes a first electrode, a second electrode, and an EL layer. The first electrode includes a first conductive layer and a second conductive layer including a region in contact with the first conductive layer. The first conductive layer has a function of reflecting light, and the second conductive layer has a function of transmitting light. The second conductive layer includes an oxide containing In and M (M represents one or more of Al, Si, Ti, Ga, Y, Zr, La, Ce, Nd, and Hf). The EL layer includes an organic acceptor material in a region in contact with the second conductive layer.