Abstract: A novel organic compound is provided. That is, a novel organic compound that is effective in improving reliability of a light-emitting element is provided. The organic compound includes a condensed ring including a pyrimidine ring and is represented by General Formula (G1). In General Formula (G1), A represents a group having 6 to 100 carbon atoms and includes at least one of an aromatic ring and a heteroaromatic ring. The aromatic ring and the heteroaromatic ring may each include a substituent. Furthermore, Q represents oxygen or sulfur. A ring X represents a substituted or unsubstituted naphthalene ring or a substituted or unsubstituted phenanthrene ring.

Abstract: A novel organometallic complex that improves emission efficiency of a light-emitting device is provided. The organometallic complex represented by General Formula (G1) is provided. In the formula, X represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aryl group. Furthermore, R1 to R3 each independently represent any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aryl group. Furthermore, n represents an integer greater than or equal to 1 and less than or equal to 4. The borate ligands may be the same or different from each other. Furthermore, n's may be the same or different from each other. In the case where n is 2 or more, X's, R1's, and R2's may be the same or different from each other.

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 long-lifetime light-emitting device is provided. The light-emitting apparatus includes a first light-emitting device and a first color conversion layer. The first color conversion layer contains a first substance. An EL layer of the first light-emitting device 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 second layer contains a third organic compound. The third layer contains a fourth organic compound. The light-emitting layer contains a fifth organic compound and a sixth organic compound. The fourth layer contains a seventh organic compound. The first organic compound is an organic compound having an electron accepting property to the second organic compound. The fifth organic compound is an emission center substance. The 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.

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: A light-emitting element having a long lifetime is provided. A light-emitting element exhibiting high emission efficiency in a high luminance region is provided. A light-emitting element includes a light-emitting layer between a pair of electrodes. The light-emitting layer contains a first organic compound, a second organic compound, and a phosphorescent compound. The first organic compound is represented by a general formula (G0). The molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000. The second organic compound is a compound having an electron-transport property. In the general formula (G0), Ar1 and Ar2 each independently represent a fluorenyl group, a spirofluorenyl group, or a biphenyl group, and Ar3 represents a substituent including a carbazole skeleton.

Abstract: A light-emitting device with high emission efficiency and reliability is provided. The light-emitting device includes first and second fluorescent light-emitting layers. A host material used in the first fluorescent light-emitting layer has a function of converting triplet excitation energy into light emission, a guest material used in the first light-emitting layer has a molecular structure including a luminophore and a protecting group, and one molecule of the guest material includes five or more protecting groups. The introduction of the protecting groups into the molecule inhibits transfer of triplet excitation energy by the Dexter mechanism from the host material to the guest material. An alkyl group or a branched-chain alkyl group is used as the protecting groups. The materials are selected such that the triplet excitation energy level of the host material in the second light-emitting layer is lower than the triplet excitation energy level of the guest material in the second light-emitting layer.

Abstract: An unsaturated hydrocarbon production apparatus includes: a light collecting device configured to collect sunlight, and to convert the sunlight into solar heat; and a heating furnace configured to heat a raw material gas containing at least any one selected from the group consisting of methane and hydrogen, methane and oxygen, and ethane with the solar heat generated by the light collecting device to 700° C. or more and 2,000° C. or less.

Abstract: A lightweight flexible light-emitting device which is able to possess a curved display portion and display a full color image with high resolution and the manufacturing process thereof are disclosed. The light-emitting device comprises: a plastic substrate; an insulating layer with an adhesive interposed therebetween; a thin film transistor over the insulating layer; a protective insulating film over the thin film transistor, a color filter over the protective insulating film; and a white-emissive light-emitting element formed over and being in contact with the thin film transistor.

Abstract: Provided is a video display device wearable on the head of a user, wherein the video display device includes a video display unit capable of switching two or more display methods, a control unit for indicating a display method to the video display unit, a first detection unit for detecting the motion of the head of a user, a second detection unit for detecting the motion of the point of view of the user, and a motion determination unit for determining the motion state of the device user by using the output from the first detection unit and the output from the second detection unit. The control unit indicates a change of display methods to the video display unit in accordance with the determination result of the motion determination unit.

Abstract: Provided is a light-emitting element with high external quantum efficiency, or a light-emitting element with a long lifetime. The light-emitting element includes, between a pair of electrodes, a light-emitting layer including a guest material and a host material, in which an emission spectrum of the host material overlaps with an absorption spectrum of the guest material, and phosphorescence is emitted by conversion of an excitation energy of the host material into an excitation energy of the guest material. By using the overlap between the emission spectrum of the host material and the absorption spectrum of the guest material, the energy smoothly transfers from the host material to the guest material, so that the energy transfer efficiency of the light-emitting element is high. Accordingly, a light-emitting element with high external quantum efficiency can be achieved.

Abstract: To provide a novel photoelectric conversion device that is highly convenient, useful, or reliable. The photoelectric conversion device includes a first electrode, a second electrode, and a first unit. The first unit is located between the first electrode and the second electrode. The first unit contains a first electron-donating material and a first electron-accepting material. The first electron-donating material is a condensed aromatic compound, and the first electron-accepting material has a perylene skeleton and two or more alkyl groups. The alkyl groups each independently have 1 to 13 carbon atoms.

Abstract: An object is to provide a light-emitting element which uses a plurality of kinds of light-emitting dopants and has high emission efficiency. In one embodiment of the present invention, a light-emitting device, a light-emitting module, a light-emitting display device, an electronic device, and a lighting device each having reduced power consumption by using the above light-emitting element are provided. Attention is paid to Forster mechanism, which is one of mechanisms of intermolecular energy transfer. Efficient energy transfer by Forster mechanism is achieved by making an emission wavelength of a molecule which donates energy overlap with the longest-wavelength-side local maximum peak of a graph obtained by multiplying an absorption spectrum of a molecule which receives energy by a wavelength raised to the fourth power.

Abstract: A furopyrazine derivative that is a novel organic compound is provided. The organic compound has a furopyrazine skeleton and is represented by General Formula (G1). In General Formula (G1), Q represents oxygen or sulfur, Ar1 represents a substituted or unsubstituted condensed aromatic ring, R1 and R2 independently represent hydrogen or a group having 1 to 100 total carbon atoms, and at least one of R1 and R2 has a hole-transport skeleton.

Abstract: To provide a light-emitting element with an improved reliability, a light-emitting element with a high current efficiency (or a high quantum efficiency), and a novel dibenzo[f,h]quinoxaline derivative that is favorably used in a light-emitting element which is one embodiment of the present invention. A light-emitting element includes an EL layer between an anode and a cathode. The EL layer includes a light-emitting layer; the light-emitting layer contains a first organic compound having an electron-transport property and a hole-transport property, a second organic compound having a hole-transport property, and a light-emitting substance; the combination of the first organic compound and the second organic compound forms an exciplex; the HOMO level of the first organic compound is lower than the HOMO level of the second organic compound; and a difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is less than or equal to 0.4 eV.

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: To provide a novel arylamine compound with a low refractive index. The provided arylamine compound includes at least one aromatic group. The aromatic group includes a first benzene ring, a second benzene ring, a third benzene ring, and at least three alkyl groups. The first benzene ring, the second benzene ring, and the third benzene ring are directly bonded in this order. The first benzene ring is bonded to nitrogen of amine. The first benzene ring may further include a substituted or unsubstituted phenyl group. The second benzene ring or the third benzene ring may further include an alkylated phenyl group. Each of first positions and third positions of two or more of the first to third benzene rings is independently bonded to another benzene ring, a benzene ring of the alkylated phenyl group, any of the at least three alkyl groups, or the nitrogen of the amine.

Abstract: A multicolor light-emitting element that utilizes fluorescence and phosphorescence and is advantageous for practical application is provided. The light-emitting element has a stacked-layer structure of a first light-emitting layer containing a host material and a fluorescent substance and a second light-emitting layer containing two kinds of organic compounds and a substance that can convert triplet excitation energy into luminescence. Note that light emitted from the first light-emitting layer has an emission peak on the shorter wavelength side than light emitted from the second light-emitting layer.

Abstract: The invention relates to: a light-emitting device which includes a first flexible substrate having a first electrode, a light-emitting layer over the first electrode, and a second electrode with a projecting portion over the light-emitting layer and a second flexible substrate having a semiconductor circuit and a third electrode electrically connected to the semiconductor circuit, in which the projecting portion of the second electrode and the third electrode are electrically connected to each other; a method for manufacturing the light-emitting device; and a cellular phone which includes a housing incorporating the light-emitting device and having a longitudinal direction and a lateral direction, in which the light-emitting device is disposed on a front side and in an upper portion in the longitudinal direction of the housing.

Abstract: To provide a light-emitting element which uses a fluorescent material as a light-emitting substance and has higher luminous efficiency. To provide a light-emitting element which includes a mixture of a thermally activated delayed fluorescent substance and a fluorescent material. By making the emission spectrum of the thermally activated delayed fluorescent substance overlap with an absorption band on the longest wavelength side in absorption by the fluorescent material in an S1 level of the fluorescent material, energy at an S1 level of the thermally activated delayed fluorescent substance can be transferred to the S1 of the fluorescent material. Alternatively, it is also possible that the S1 of the thermally activated delayed fluorescent substance is generated from part of the energy of a T1 level of the thermally activated delayed fluorescent substance, and is transferred to the S1 of the fluorescent material.