Abstract: A novel organometallic complex is provided. The organometallic complex is represented by General Formula (G1). In the organometallic complex represented by General Formula (G1), each of R1, R13, and R14 independently represents an alkyl group that has 1 to 6 carbon atoms and includes deuterium, each of R2 to R12 independently represents hydrogen (including deuterium) or an alkyl group that has 1 to 6 carbon atoms and includes deuterium, each of R15 to R21 independently represents hydrogen (including deuterium), and n represents 1 or 2.

Abstract: A novel organic compound, a benzofuropyrimidine derivative or a benzothienopyrimidine derivative is provided. The organic compound has a structure in which a benzothienocarbazolyl ring, a benzofurocarbazolyl ring, an indolocarbazolyl ring, or an indenocarbazolyl ring is bonded to the 8-position of a benzofuropyrimidine ring or a benzothienopyrimidine ring directly or through an aromatic hydrocarbon ring. That is, the organic compound is represented by General Formula (G1) below.

Abstract: A novel organic compound, a benzofuropyrimidine derivative or a benzothienopyrimidine derivative is provided. The organic compound has a structure in which a benzothienocarbazolyl ring, a benzofurocarbazolyl ring, an indolocarbazolyl ring, or an indenocarbazolyl ring is bonded to the 8-position of a benzofuropyrimidine ring or a benzothienopyrimidine ring directly or through an aromatic hydrocarbon ring. That is, the organic compound is represented by General Formula (G1) below.

Abstract: A light-emitting device with high emission efficiency is provided. The light-emitting device includes an anode, a cathode, and an EL layer positioned between the anode and the cathode. The EL layer includes a light-emitting layer and an electron-transport layer; the light-emitting layer includes a light-emitting material; the electron-transport layer includes an organic compound having an electron-transport property and a metal complex of an alkali metal; the ordinary refractive index of the organic compound having an electron-transport property in a peak wavelength of light emitted from the light-emitting material is greater than or equal to 1.50 and less than or equal to 1.75; and the ordinary refractive index of the metal complex of an alkali metal in the peak wavelength of the light emitted from the light-emitting material is greater than or equal to 1.45 and less than or equal to 1.70.

Abstract: A light-emitting device with high emission efficiency is provided. The light-emitting device includes an anode, a cathode, and an EL layer positioned between the anode and the cathode. The EL layer includes a light-emitting layer and an electron-transport layer; the light-emitting layer includes a light-emitting material; the electron-transport layer includes an organic compound having an electron-transport property and a metal complex of an alkali metal; the ordinary refractive index of the organic compound having an electron-transport property in a peak wavelength of light emitted from the light-emitting material is greater than or equal to 1.50 and less than or equal to 1.75; and the ordinary refractive index of the metal complex of an alkali metal in the peak wavelength of the light emitted from the light-emitting material is greater than or equal to 1.45 and less than or equal to 1.70.

Abstract: Provided is an inexpensive light-emitting device with high emission efficiency. Provided is a light-emitting device including an anode, a cathode, an EL layer positioned between the anode and the cathode; the EL layer includes a hole-transport region, a light-emitting layer, and an electron-transport region; the hole-transport region is positioned between the anode and the light-emitting layer; the electron-transport region is positioned between the cathode and the light-emitting layer; the hole-transport region contains any one of a sulfonic acid compound, a fluorine compound, and a metal oxide; the electron-transport region contains an organic compound having an electron-transport property; and an ordinary refractive index of the organic compound having an electron-transport property with respect to light with a wavelength greater than or equal to 455 nm and less than or equal to 465 nm is higher than or equal to 1.50 and lower than or equal to 1.75.

Abstract: An inexpensive light-emitting device with high emission efficiency is provided. A light-emitting device including an anode, a cathode, and an EL layer positioned between the anode and the cathode is provided. The EL layer includes a hole-transport region, a light-emitting layer, and an electron-transport region. The hole-transport region is positioned between the anode and the light-emitting layer. The electron-transport region is positioned between the cathode and the light-emitting layer. The hole-transport region contains a heteropoly acid and an organic compound having a ?-electron rich aromatic ring or contains a heteropoly acid and an organic compound having a ?-electron rich heteroaromatic ring. The electron-transport region contains an organic compound with an electron-transport property. The ordinary refractive index of the organic compound with an electron-transport property is higher than or equal to 1.50 and lower than or equal to 1.

Abstract: An electron-transport layer material with a low refractive index is provided. An organic compound represented by General Formula (G1) is provided. In General Formula (G1), one to three of Q1 to Q3 represent N and when one or two of Q1 to Q3 represent N, the remaining two or one of Q1 to Q3 represent CH. Furthermore, R0 represents any of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, and a group represented by Formula (G1-1). At least one of R1 to R15 represents a substituted or unsubstituted group including any one of a pyrimidinyl group, a pyrazinyl group, and a triazinyl group, and the others each independently represent any of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 carbon atoms forming a ring, and a substituted or unsubstituted pyridinyl group.

Abstract: A novel light-emitting device, a novel light-emitting apparatus, a novel electronic device, a novel display device, and a novel lighting device which are highly convenient, useful, or reliable are provided. The light-emitting device includes a first electrode, a second electrode, a first layer, and a second layer. The second electrode includes a region overlapping with the first electrode, the first layer includes a region sandwiched between the first electrode and the second electrode, the first layer includes a light-emitting material, the light-emitting material has a function of emitting photoluminescent light in a solution, the photoluminescent light has a first spectrum, the first spectrum has a maximum peak at a wavelength ?1, and the wavelength ?1 is in the range greater than or equal to 440 nm and less than or equal to 470 nm.

Abstract: A novel organic compound, a benzofuropyrimidine derivative or a benzothienopyrimidine derivative is provided. The organic compound has a structure in which a benzothienocarbazolyl ring, a benzofurocarbazolyl ring, an indolocarbazolyl ring, or an indenocarbazolyl ring is bonded to the 8-position of a benzofuropyrimidine ring or a benzothienopyrimidine ring directly or through an aromatic hydrocarbon ring. That is, the organic compound is represented by General Formula (G1) below.

Abstract: A light-emitting device with high emission efficiency is provided. The light-emitting device includes an anode, a cathode, and an EL layer positioned between the anode and the cathode. The EL layer includes a light-emitting layer and an electron-transport layer; the light-emitting layer includes a light-emitting material; the electron-transport layer includes an organic compound having an electron-transport property and a metal complex of an alkali metal; the ordinary refractive index of the organic compound having an electron-transport property in a peak wavelength of light emitted from the light-emitting material is greater than or equal to 1.50 and less than or equal to 1.75; and the ordinary refractive index of the metal complex of an alkali metal in the peak wavelength of the light emitted from the light-emitting material is greater than or equal to 1.45 and less than or equal to 1.70.

Abstract: A light-emitting device material with a low refractive index is provided. The light-emitting device material contains an organic compound which has a pyridine skeleton, a diazine skeleton, or a triazine skeleton and in which the proportion of carbon atoms forming a bond by sp3 hybrid orbitals is within a certain range. The light-emitting device material contains an organic compound including at least one six-membered heteroaromatic ring having 1 to 3 nitrogen atoms and a plurality of aromatic hydrocarbon rings each having 6 to 14 carbon atoms in a ring. At least two of the plurality of aromatic hydrocarbon rings are benzene rings. The organic compound has a plurality of hydrocarbon groups forming a bond by the sp3 hybrid orbitals. The ordinary refractive index of a layer containing the organic compound with respect to light with a wavelength in the range from 455 nm to 465 nm is 1.5 to 1.75.