Abstract: The heat resistance of an organic semiconductor device including a step of forming an aluminum oxide film over and in contact with an organic semiconductor layer is improved. A heating step is performed after a layer containing an organometallic compound for a mask for an organic semiconductor layer, which is represented by General Formula (G1) below, is provided over the organic semiconductor layer. In General Formula (G1), Ar represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, X represents oxygen or sulfur, M represents a metal, n represents an integer greater than or equal to 1 and less than or equal to 5, and n is the same as the valence of the metal M. Note that when n is greater than or equal to 2, a plurality of Ars may be the same or different and Xs may be the same or different.

Abstract: An object is to provide a highly reliable display unit having a function of sensing light. The display unit includes a light-receiving device and a light-emitting device. The light-receiving device includes an active layer between a pair of electrodes. The light-emitting device includes a hole-injection layer, a light-emitting layer, and an electron-transport layer between a pair of electrodes. The light-receiving device and the light-emitting device share one of the electrodes, and may further share another common layer between the pair of electrodes. The hole-injection layer is in contact with an anode and contains a first compound and a second compound. The electron-transport property of the electron-transport layer is low; hence, the light-emitting layer is less likely to have excess electrons. Here, the first compound is the material having a property of accepting electrons from the second compound.

Abstract: A quinoxaline derivative that is a novel organic compound is provided. A quinoxaline derivative represented by General Formula (G1) has a structure in which a quinoxaline skeleton is bonded to the 9-position of an anthracene skeleton, the 10-position of the anthracene skeleton is bonded to a heteroaromatic ring, and the 3-position of the heteroaromatic ring is nitrogen. In General Formula (G1) shown above, a and b each independently represent a substituted or unsubstituted arylene group having 6 to 13 carbon atoms in a ring. In addition, m and n are each independently 0, 1, or 2.

Abstract: An organic compound that can provide a light-emitting device having a high hole-transport property and high reliability. An organic compound represented by General Formula (G1) shown below is provided. In General Formula (G1), X represents a sulfur atom or an oxygen atom, each of R1 to R22 independently represents any one of hydrogen, halogen, a nitrile group, an alkenyl group, a vinyl group, an alkynyl group, a straight-chain alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylsilyl group having 3 to 12 carbon atoms, an aryl group having 6 to 30 carbon atoms, and a heteroaryl group having 2 to 30 carbon atoms. At least one of R16 to R22 represents a naphthyl group, n represents an integer of 0 to 4, and Ar1 represents a fluorenyl group or a spirofluorenyl group.

Abstract: A light-emitting element which includes a plurality of light-emitting layers between a pair of electrodes and has low driving voltage and high emission efficiency is provided. A light-emitting element including first to third light-emitting layers between a cathode and an anode is provided. The first light-emitting layer includes a first phosphorescent material and a first electron-transport material; the second light-emitting layer includes a second phosphorescent material and a second electron-transport material; the third light-emitting layer includes a fluorescent material and a third electron-transport material; the first to third light-emitting elements are provided in contact with an electron-transport layer positioned on a cathode side; and a triplet excitation energy level of a material included in the electron-transport layer is lower than triplet excitation energy levels of the first electron-transport material and the second electron-transport material.

Abstract: Provided is a novel light-emitting element, a light-emitting element with a long lifetime, or a light-emitting element with high emission efficiency. The light-emitting element includes an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer containing a fluorescent substance and a host material, a first electron-transport layer containing a first electron-transport material, and a second electron-transport layer containing a second electron-transport material, which are in contact with each other and in this order. The LUMO level of each of the host material and the second electron-transport material is higher than the LUMO level of the first electron-transport material.

Abstract: To provide a display apparatus with high display quality. To provide a display apparatus which includes first and second light-emitting devices and in which the first and second light-emitting devices include a common electrode with a light-transmitting property, the first light-emitting device includes a first electrode, a first EL layer, and a first auxiliary electrode with a light-transmitting property, the second light-emitting device includes a second electrode, a second EL layer, and a second auxiliary electrode with a light-transmitting property, the first EL layer is between the first electrode and the common electrode, the second EL layer is between the second electrode and the common electrode, the first auxiliary electrode is between the first EL layer and the common electrode, the second auxiliary electrode is between the second EL layer and the common electrode, and the first auxiliary electrode has a larger thickness than the second auxiliary electrode.

Abstract: A novel compound, a synthesis method thereof, and an organic device including the novel compound are provided. A compound represented by General Formula (G1) is provided. In General Formula (G1), each of R1, R2, and R5 to R7 independently represents any of hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 1 to 60 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 60 carbon atoms. R3 represents a condensed ring composed of 4 to 10 rings containing nitrogen as an element forming the ring, and R4 represents any of a substituted or unsubstituted condensed ring having 1 to 60 carbon atoms, a substituted or unsubstituted aryl group with a molecular weight of 78 or more, and a substituted or unsubstituted heteroaryl group with a molecular weight of 80 or more. At least one of A1 to A3 represents nitrogen, and each of the others represents substituted carbon.

Abstract: An object is to provide a highly reliable display unit having a function of sensing light. The display unit includes a light-receiving device and a light-emitting device. The light-receiving device includes an active layer between a pair of electrodes. The light-emitting device includes a hole-injection layer, a light-emitting layer, and an electron-transport layer between a pair of electrodes. The light-receiving device and the light-emitting device share one of the electrodes, and may further share another common layer between the pair of electrodes. The hole-injection layer is in contact with an anode and contains a first compound and a second compound. The electron-transport property of the electron-transport layer is low; hence, the light-emitting layer is less likely to have excess electrons. Here, the first compound is the material having a property of accepting electrons from the second compound.

Abstract: Provided is a novel light-emitting element, a light-emitting element with a long lifetime, or a light-emitting element with high emission efficiency. The light-emitting element includes an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer containing a fluorescent substance and a host material, a first electron-transport layer containing a first electron-transport material, and a second electron-transport layer containing a second electron-transport material, which are in contact with each other and in this order. The LUMO level of each of the host material and the second electron-transport material is higher than the LUMO level of the first electron-transport material.

Abstract: A novel light-emitting device, a light-emitting device with high emission efficiency, a light-emitting device with a long lifetime, or a light-emitting device with low driving voltage is provided. An EL layer includes a first layer, a second layer, a third layer, a light-emitting layer, and a fourth layer in this order from the anode side. The first layer contains a first organic compound and a second organic compound. The fourth layer contains a seventh organic compound. The first organic compound exhibits an electron-accepting property with respect to the second organic compound. A HOMO level of the second organic compound is higher than or equal to ?5.7 eV and lower than or equal to ?5.4 eV. The fourth layer includes a region where the amount of seventh organic compound is large and a region where the amount of seventh organic compound is small in the thickness direction.

Abstract: A novel compound for a host material is provided. A compound for a host material that is capable of increasing the lifetime of a light-emitting device is provided. A light-emitting device with a long lifetime is provided. A material whose thermophysical properties such as a glass transition temperature are high is provided. An anthracene compound for a host material represented by General Formula (G1) below is provided. (Note that in General Formula (G1), R1 to R7 each independently represent hydrogen or an aryl group having 1 to 25 carbon atoms.

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. A gap is provided between the second light-emitting device and the first light-emitting device. The first light-emitting device includes a first pixel electrode, a common electrode, and a first unit. The first unit is sandwiched between the first pixel electrode and the common electrode and contains a first organic compound L. The first organic compound L includes a plurality of 2,2?-bipyridine skeletons or a plurality of 1,10?-phenanthroline skeletons. The second light-emitting device includes a second pixel electrode, the common electrode, and a third unit. The third unit is sandwiched between the second pixel electrode and the common electrode. The third unit contains the first organic compound L. A gap is provided between the third unit and the first unit.

Abstract: A method for removing oxygen from an oxygen adduct of anthracene, which is generated by irradiation with ultraviolet rays, is provided. Alternatively a method for manufacturing an electronic device or a display device with favorable reliability is provided. A method for manufacturing an electronic device, including a step of irradiating a layer including an organic compound including an anthracene structure with ultraviolet rays at an energy density higher than or equal to 1 mJ/cm2 and lower than or equal to 1000 mJ/cm2 in an atmosphere where oxygen exists and a step of performing heating at a temperature higher than or equal to 80° C. in an atmosphere with an oxygen concentration lower than or equal to 300 ppm is provided.

Abstract: A light-emitting device with a long lifetime is provided. In a light-emitting device that includes an EL layer between a pair of electrodes, a light-emitting layer included in the EL layer has a functional stacked-layer structure, whereby the efficiency and reliability of the light-emitting device can be increased.

Abstract: A light-emitting element that includes a fluorescent material and has a high emission efficiency is provided. A light-emitting element in which a delayed fluorescence component due to TTA accounts for a high proportion of emissive components is provided. A novel light-emitting device with a high emission efficiency and a low power consumption is provided. A light-emitting element includes an anode, a cathode, and an EL layer. The EL layer includes a light-emitting layer including a host material and an electron-transport layer including a first material in contact with the light-emitting layer. The LUMO level of the first material is lower than that of the host material. The proportion of a delayed fluorescence component due to TTA is greater than or equal to 10 percent of the light emission from the EL layer. The proportion of the delayed fluorescence component due to TTA may be greater than or equal to 15 percent of the light emission.

Abstract: A novel light-emitting device is provided. Alternatively, a light-emitting device with high emission efficiency is provided. Alternatively, a light-emitting device having a long lifetime is provided. Alternatively, a light-emitting device having low driving voltage is provided. A light-emitting device including an EL layer including a first layer, a second layer, a third layer, a light-emitting layer, and a fourth layer in this order from the anode side is provided. The first layer includes a first organic compound and a second organic compound. The fourth layer includes a seventh organic compound. The first organic compound exhibits an electron-accepting property with respect to the second organic compound. The HOMO level of the second organic compound is from ?5.7 eV to ?5.4 eV. The HOMO level of the seventh organic compound is ?6.0 eV or higher.

Abstract: A novel mixed material for a light-emitting device with improved heat resistance is provided. The mixed material for a light-emitting device includes a first heteroaromatic compound and a second heteroaromatic compound. The first heteroaromatic compound includes a first heteroaromatic ring. The first heteroaromatic ring includes a ring including two or more nitrogen atoms and any one of a benzene ring and a pyridine ring or a ring including a diazine ring or a triazine ring. The second heteroaromatic compound includes a second heteroaromatic ring. The second heteroaromatic ring includes a ring including two or more nitrogen atoms and any one of a benzene ring and a pyridine ring or a ring including a diazine ring or a triazine ring. A structure of the first heteroaromatic ring is different from a structure of the second heteroaromatic ring.

Abstract: An increase in the voltage of an organic semiconductor device including a step of forming an aluminum oxide film over and in contact with an organic semiconductor layer is inhibited. A layer containing an organometallic compound for a mask for an organic semiconductor layer, which is represented by General Formula (G1) below, is provided between the organic semiconductor layer and the aluminum oxide film. In General Formula (G1), Ar represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, X represents oxygen or sulfur, M represents a metal, n represents an integer greater than or equal to 1 and less than or equal to 5, and n is the same as the valence of the metal M. Note that when n is greater than or equal to 2, a plurality of Ars may be the same or different and Xs may be the same or different.

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 first unit, and a first layer, and the first unit is held between the first electrode and the second electrode and includes a second layer, a third layer, and a fourth layer. The second layer is held between the third layer and the fourth layer, and the second layer contains a light-emitting material. The fourth layer is held between the second layer and the second electrode and contains a first organic compound. The first organic compound has a ?-electron deficient heteroaromatic ring skeleton and a ?-electron rich heteroaromatic ring skeleton and has a HOMO level higher than or equal to ?6.0 eV and lower than or equal to ?5.6 eV. The first layer is held between the first electrode and the first unit, is in contact with the first electrode, and contains a second organic compound and a third organic compound.