Abstract: Emission efficiency of a light-emitting element is improved. The light-emitting element has a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first light-emitting layer and a second light-emitting layer. The first light-emitting layer includes a fluorescent material and a host material. The second light-emitting layer includes a phosphorescent material, a first organic compound, and a second organic compound. An emission spectrum of the second light-emitting layer has a peak in a yellow wavelength region. The first organic compound and the second organic compound form an exciplex.

Abstract: A novel display apparatus that is highly convenient, useful, or reliable is provided. The display apparatus includes a first light-emitting device and a second light-emitting device, and the second light-emitting device is adjacent to the first light-emitting device. The first light-emitting device includes a first unit emitting light, a second unit emitting light, a first intermediate layer, and a first layer. The first intermediate layer is interposed between the second unit and the first unit. The first layer is interposed between the first intermediate layer and the first unit. In the first layer, unpaired electrons are able to be observed at a spin density greater than or equal to 1×1016 spins/cm3 and less than or equal to 1×1018 spins/cm3. The second light-emitting device includes a third unit emitting light, a fourth unit emitting light, a second intermediate layer, and a second layer. The second intermediate layer is interposed between the fourth unit and the third unit.

Abstract: A light-emitting device, an electronic device, or a lighting device with low power consumption and high reliability is provided. The light-emitting device includes a first light-emitting element, a second light-emitting element, a third light-emitting element, and a fourth light-emitting element. The first to fourth light-emitting elements include the same EL layer between an anode and a cathode. The EL layer includes a first light-emitting layer and a second light-emitting layer. The first light-emitting layer contains a fluorescent substance. The peak wavelength of an emission spectrum of the fluorescent substance in a toluene solution of the fluorescent substance is 440 nm to 460 nm, preferably 440 nm to 455 nm. The second light-emitting layer contains a phosphorescent substance. The first light-emitting element exhibits blue emission. The second light-emitting element exhibits green emission. The third light-emitting element exhibits red emission.

Abstract: A novel light-emitting device with high emission efficiency is provided. A light-emitting device with a high blue index (BI) is provided. A light-emitting device with low power consumption is provided. A light-emitting device including a first electrode and a second electrode which are a reflective electrode and a semi-transmissive and semi-reflective electrode, and an EL layer sandwiched between the first electrode and the second electrode, where the EL layer contains an emission center substance, where when the emission center substance in the EL layer includes only one kind of substance, photon energy of a peak wavelength of light emitted from the light-emitting device is designed from an average value of photon energy of light emitted by the emission center substance in a solution state and emission edge energy on a short wavelength side of an emission spectrum of the emission center substance in the solution state.

Abstract: A light-emitting device with a high resolution and high efficiency is provided. The light-emitting device includes a first EL layer, an intermediate layer, and a second EL layer between first and second electrodes. The first EL layer is provided between the first electrode and the intermediate layer, and the second EL layer is provided between the second electrode and the intermediate layer. Side surfaces of the first EL layer, the intermediate layer, and the second EL layer are substantially aligned. The first EL layer includes a layer having an electron-transport property. The intermediate layer is provided in contact with the layer having an electron-transport property. The intermediate layer includes a first organic compound and an alkali metal or a compound of an alkali metal. The layer having an electron-transport property includes a second organic compound. The second organic compound has a higher glass transition temperature than the first organic compound.

Abstract: A light-emitting device includes a light-emitting layer containing a light-emitting substance and a first organic compound. The light-emitting substance is an organometallic complex containing a central metal and ligands. One of the ligands includes a skeleton formed by a ring A1 and a pyridine ring bonded to each other. The ring A1 represents an aromatic ring or a heteroaromatic ring. The pyridine ring includes an alkyl group having 1 to 6 carbon atoms and being substituted with deuterium. The first organic compound includes an electron-transport skeleton and first and second substituents that are bonded to the electron-transport skeleton. The electron-transport skeleton includes a heteroaromatic ring having two or more nitrogen atoms. The first substituent includes one or both of an aromatic ring and a heteroaromatic ring. The second substituent includes a skeleton having a hole-transport property.

Abstract: A green phosphorescent light-emitting device with a long lifetime is provided. The light-emitting device includes a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is between the first electrode and the second electrode. The light-emitting layer includes a first organic compound, a second organic compound, and a phosphorescent light-emitting substance. The first organic compound includes a heteroaromatic ring skeleton and an aromatic hydrocarbon group. The second organic compound includes a bicarbazole skeleton. The lowest triplet excited level of the first organic compound is derived from only the aromatic hydrocarbon group. The energy of the lowest triplet excited level of the second organic compound is higher than or equal to 2.20 eV and lower than or equal to 2.65 eV.

Abstract: Emission efficiency of a light-emitting element is improved. The light-emitting element has a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first light-emitting layer and a second light-emitting layer. The first light-emitting layer includes a fluorescent material and a host material. The second light-emitting layer includes a phosphorescent material, a first organic compound, and a second organic compound. An emission spectrum of the second light-emitting layer has a peak in a yellow wavelength region. The first organic compound and the second organic compound form an exciplex.

Abstract: To provide a light-emitting element in which an organic compound layer can be processed at once by a photolithography technique. A first electrode and an organic compound layer including an electron-injection layer are formed over an insulating surface. The electron-injection layer is the outermost layer of the organic compound layer and contains an organic compound having a basic skeleton and an acid dissociation constant pKa of greater than or equal to 1. A sacrificial layer and a mask are formed over the electron-injection layer and the sacrificial layer is processed into an island shape using the mask. With use of the island-shaped sacrificial layer as a mask, the organic compound layer is processed into an island shape to cover the first electrode. Part of the island-shaped sacrificial layer is removed with an acidic chemical solution to expose the electron-injection layer. A second electrode is formed to cover the electron-injection layer.

Abstract: A plurality of light-emitting elements having a structure in which an organic compound layer as a whole is processed with a photolithography technique is provided. A light-emitting element is formed over an insulating layer and includes a first electrode, a second electrode, and an organic compound layer. The organic compound layer is positioned between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer and an electron-injection layer. The electron-injection layer is in contact with the second electrode, and the electron-injection layer includes an organic compound having a basic skeleton and an acid dissociation constant pKa of 1 or more. Layers included in the organic compound layer have substantially the same contour, and the organic compound layer is separated from organic compound layers of the other light-emitting elements of the plurality of light-emitting elements.

Abstract: A composition for a light-emitting device is provided. The composition is formed by mixing a first organic compound having a benzofuropyrimidine skeleton, and a second organic compound represented by General Formula (Q1): R1 to R14 each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted monocyclic saturated hydrocarbon having 5 to 7 carbon atoms in a ring, a substituted or unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms in a ring, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms in a ring, or a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms in a ring. Furthermore, ?1 and ?2 each represent any of an unsubstituted ?-naphthyl group, an unsubstituted biphenyl group, and an unsubstituted terphenyl group, and at least one of ?1 and ?2 is an unsubstituted ?-naphthyl group.

Abstract: A light-emitting device with high resistance to heat in a fabrication process is provided. The light-emitting device includes an EL layer between an anode and a cathode, and the EL layer includes at least a light-emitting layer. The light-emitting device includes, between the light-emitting layer and the cathode, a first layer in contact with the light-emitting layer. The light-emitting layer includes a light-emitting substance, a first organic compound, and a second organic compound. The first layer includes a third organic compound different from the first organic compound and the second organic compound. The light-emitting substance emits green to yellow light. The third organic compound includes a bicarbazole skeleton and a heteroaromatic ring skeleton including one selected from a pyridine ring, a diazine ring, and a triazine ring.

Abstract: A light-emitting device with high heat resistance is provided. The light-emitting layer device includes an anode, a cathode; and an EL layer between the anode and the cathode. The EL layer includes a light-emitting layer and a first layer. The first layer is between the light-emitting layer and the cathode. The light-emitting layer is in contact with the first layer. The light-emitting layer includes a first organic compound and a light-emitting substance. The first layer includes a second organic compound. The light-emitting substance is a substance that emits blue light. The first organic compound is an organic compound including a fused aromatic hydrocarbon ring. The second organic compound is an organic compound including a heteroaromatic ring skeleton including one selected from a pyridine ring, a diazine ring, and a triazine ring; and a bicarbazole skeleton.

Abstract: A light-emitting device having favorable heat resistance is provided. The light-emitting device includes an anode, a cathode, and an EL layer positioned between the first anode and the cathode. The EL layer includes a light-emitting layer and a first layer. The first layer is positioned between the light-emitting layer and the cathode. The light-emitting layer and the first layer are in contact with each other. The light-emitting layer contains a first organic compound, a second organic compound, and a light-emitting substance. The first layer contains a third organic compound. The first organic compound and the third organic compound each have an electron-transport property. The second organic compound has a hole-transport property. The light-emitting substance emits red light. The first organic compound is represented by General Formula (G100). The third organic compound is represented by General Formula (G300).

Abstract: One object of this invention is to provide a novel light-emitting device with low power consumption. The light-emitting device includes a first light-emitting element and a second light-emitting element. The first light-emitting element includes a first electrode, a second electrode, and a light-emitting layer. The second light-emitting element includes the first electrode, a third electrode, and the light-emitting layer. The second electrode comprises only a first conductive film, and the third electrode comprises a second conductive film and a third conductive film. The first electrode has a function of reflecting light. The second conductive film has functions of reflecting light and transmitting light. The first conductive film and the third conductive film each have a function of transmitting light.

Abstract: A display panel includes a plurality of light-emitting elements. Light emitted from a first light-emitting element has a CIE 1931 chromaticity coordinate x of greater than 0.680 and less than or equal to 0.720 and a CIE 1931 chromaticity coordinate y of greater than or equal to 0.260 and less than or equal to 0.320. Light emitted from a second light-emitting element has a CIE 1931 chromaticity coordinate x of greater than or equal to 0.130 and less than or equal to 0.250 and a CIE 1931 chromaticity coordinate y of greater than 0.710 and less than or equal to 0.810. Light emitted from a third light-emitting element has a CIE 1931 chromaticity coordinate x of greater than or equal to 0.120 and less than or equal to 0.170 and a CIE 1931 chromaticity coordinate y of greater than or equal to 0.020 and less than 0.060.

Abstract: A novel light-emitting device with high emission efficiency is provided. The light-emitting device includes a first electrode, a second electrode, an EL layer, and an insulating layer. The EL layer is positioned between the first electrode and the second electrode. The EL layer includes at least a light-emitting layer, an electron-transport layer, and an electron-injection layer. The electron-transport layer is positioned over the light-emitting layer. The insulating layer is in contact with an end portion of the light-emitting layer and an end portion of the electron-transport layer. The electron-injection layer is positioned over the electron-transport layer. The electron-injection layer includes an alkali metal compound and a reducing agent.

Abstract: Emission efficiency of a light-emitting element is improved. The light-emitting element has a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first light-emitting layer and a second light-emitting layer. The first light-emitting layer includes a fluorescent material and a host material. The second light-emitting layer includes a phosphorescent material, a first organic compound, and a second organic compound. An emission spectrum of the second light-emitting layer has a peak in a yellow wavelength region. The first organic compound and the second organic compound form an exciplex.

Abstract: To provide a light-emitting device not only including a light-emitting layer in which energy is efficiently transferred from a host material to a guest material but also having high reliability. In the light-emitting device, the light-emitting layer includes an organic compound having a specific naphthofuropyrazine skeleton as a host material and a light-emitting substance (e.g., an organometallic complex) whose T1 level (TG) is within a certain range as a guest material, thereby increasing not only the efficiency of energy transfer from the host material to the guest material but also the reliability.

Abstract: Emission efficiency of a light-emitting element is improved. The light-emitting element has a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first light-emitting layer and a second light-emitting layer. The first light-emitting layer includes a fluorescent material and a host material. The second light-emitting layer includes a phosphorescent material, a first organic compound, and a second organic compound. An emission spectrum of the second light-emitting layer has a peak in a yellow wavelength region. The first organic compound and the second organic compound form an exciplex.