Abstract: A display apparatus having a function of emitting visible light and infrared light and a light detection function is provided. The display apparatus includes a first light-emitting device, a second light-emitting device, and a light-receiving device in a display portion. The first light-emitting device emits both visible light and infrared light and the second light-emitting device emits visible light. The light-receiving device has a function of absorbing at least part of visible light and infrared light. The first light-emitting device includes a first pixel electrode, a first light-emitting layer, a second light-emitting layer, and a common electrode. The second light-emitting device includes a second pixel electrode, a third light-emitting layer, and the common electrode. The light-receiving device includes a third pixel electrode, an active layer, and the common electrode. The first light-emitting layer includes a light-emitting material emitting infrared light.

Abstract: A novel light-emitting device with a microcavity structure which can improve the emission efficiency compared to the conventional one is provided. In a light-emitting device with a microcavity structure that emits light in a near-infrared range, reflectance of one or both of a first electrode (reflective electrode) and a second electrode (semi-transmissive and semi-reflective electrode) with respect to light in a near-infrared range (e.g., light with a wavelength of 850 nm) is higher than the reflectance thereof with respect to light in a visible light range (greater than or equal to 400 nm and less than 750 nm).

Abstract: To provide a light-emitting element with high emission efficiency and low driving voltage. The light-emitting element includes a guest material and a host material. A LUMO level of the host material is higher than a LUMO level of the host material, and a HOMO level of the guest material is lower than a HOMO level of the host material. The guest material has a function of converting triplet excitation energy into light emission. The difference between a singlet excitation energy level and a triplet excitation energy level of the host material is greater than 0 eV and less than or equal to 0.2 eV. The energy difference between the LUMO level and the HOMO level of the host material is larger than or equal to light emission energy of the guest material.

Abstract: An object is to provide an organic compound with a low refractive index. Alternatively, a novel organic compound with a low refractive index and an electron-donating property is provided. Alternatively, an EL device with high emission efficiency is provided. An organic compound having an arylamine skeleton including a fluorine atom or an acridine skeleton including a fluorine atom and an EL device using the organic compound are provided. The EL device preferably includes a hole-injection layer containing the organic compound having an arylamine skeleton including a fluorine atom or an acridine skeleton including a fluorine atom and a substance showing an electron-accepting property with respect to the organic compound.

Abstract: A light-emitting device with high outcoupling efficiency is provided. In the light-emitting device including a light-emitting layer between a pair of electrodes, a low refractive index layer containing an organic compound and an inorganic compound is provided between the light-emitting layer and an anode or between the light-emitting layer and a cathode, and the low refractive index layer has a refractive index of less than or equal to 1.80 at a wavelength of light extracted from the light-emitting layer.

Abstract: Providing a light-emitting element emitting light in a broad emission spectrum. A combination of a first organic compound and a second organic compound forms an exciplex. The first organic compound has a function of converting triplet-excitation energy into light emission. The lowest triplet excitation level of the second organic compound is higher than or equal to the lowest triplet excitation level of the first organic compound, and the lowest triplet excitation level of the first organic compound is higher than or equal to the lowest triplet excitation level of the exciplex. Light emission from a light-emitting layer includes light emission from the first organic compound and light emission from the exciplex.

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.

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 novel organometallic complex is provided. One embodiment of the present invention provides a novel organometallic complex having a high quantum yield. An Ir complex has a structure including a 1H-naphtho[1,2-d]imidazole skeleton as a ligand and being represented by General Formula (G-1) below. Of Ns included in the 1H-naphtho[1,2-d]imidazole skeleton, N that is not bonded to Ir is bonded to a substituted or unsubstituted aryl group. In General Formula (G-1), each of R1 to R10 independently represents any of hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, and an electron-withdrawing group, and Ar represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms.

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: The emission efficiency of a light-emitting device that emits near-infrared light is increased. The reliability of a light-emitting device that emits near-infrared light is increased. A light-emitting device using an organic compound that emits light having a maximum peak wavelength greater than or equal to 760 nm and less than or equal to 900 nm is provided. An organometallic complex represented by General Formula (G1) is provided. In the formula, each of R1 to R11 independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms; at least two of R1 to R4 and at least two of R5 to R9 represent an alkyl group having 1 to 6 carbon atoms; X represents a substituted or unsubstituted benzene ring or naphthalene ring; n is 2 or 3; and L represents a monoanionic ligand.

Abstract: To provide a light-emitting element with high emission efficiency and low driving voltage. The light-emitting element includes a guest material and a host material. A LUMO level of the host material is higher than a LUMO level of the host material, and a HOMO level of the guest material is lower than a HOMO level of the host material. The guest material has a function of converting triplet excitation energy into light emission. The difference between a singlet excitation energy level and a triplet excitation energy level of the host material is greater than 0 eV and less than or equal to 0.2 eV. The energy difference between the LUMO level and the HOMO level of the host material is larger than or equal to light emission energy of the guest material.

Abstract: Provided is a light-emitting element including a fluorescence-emitting material with high emission efficiency. The light-emitting element includes a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first organic compound, a second organic compound, and a guest material. The first organic compound has a function of emitting a thermally activated delayed fluorescence at room temperature. The guest material has a function of emitting fluorescence. A HOMO level of the first organic compound higher than or equal to a HOMO level of the second organic compound. A LUMO level of the first organic compound is lower than or equal to a LUMO level of the second organic compound.

Abstract: An electronic device with high outcoupling efficiency or a high light-trapping effect is provided. The electronic device includes a first layer and a second layer between a first electrode and a second electrode, the first layer is included between the first electrode and the second layer, the first layer includes a first organic compound and a first substance, the refractive index of a thin film of the first organic compound is higher than or equal to 1 and lower than or equal to 1.75, the first substance has an electron-accepting property, and the second layer has a function of emitting or absorbing light.

Abstract: Providing a novel organometallic complex represented by Structure Formula (G1). A1 to A4 independently represent an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. R1 to R5 independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and a cyano group, wherein at least one of R1 to R5 represents a cyano group. R11 to R14 independently represent an alkyl group having 2 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. R15 and R16 independently represent any one of hydrogen, a methyl group, and an ethyl group. Note that R11 and R12 may be bonded to each other to form a ring, and R13 and R14 may be bonded to each other to form a ring.

Abstract: A highly reliable light-emitting element having high emission efficiency is provided. The light-emitting element includes a light-emitting layer including a first organic compound and a guest material. The first organic compound has a substituted or unsubstituted carbazole skeleton. In the light-emitting layer, the weight ratio of a hydrocarbon group substitution product in which at least one of hydrogen atoms in the first organic compound is substituted by a hydrocarbon group having 1 to 6 carbon atoms to the first organic compound is greater than 0 and less than or equal to 0.1.

Abstract: In a light-emitting element, a layer including an organic compound includes a light-emitting layer; the light-emitting layer includes a tris iridium complex; and on the assumption that there is a rectangle which covers the iridium complex and in which at least one atom of the iridium complex is located over each of four sides when the iridium complex is two-dimensionally seen from a direction of a C3 symmetry axis of the iridium complex, A×B/C2 is greater than or equal to 2.5, where A represents a maximum length of a long side of the rectangle, B represents a length of a short side of the rectangle when the length of the long side of the rectangle is A, and C represents a width in the direction of the C3 symmetry axis when the iridium complex is two-dimensionally seen from a normal direction of the C3 symmetry axis.

Abstract: A light-emitting element having low driving voltage and high emission efficiency is provided. In the light-emitting element, a combination of a guest material and a host material forms an exciplex. The guest material is capable of converting triplet excitation energy into light emission. Light emission from the light-emitting layer includes light emission from the guest material and light emission from the exciplex. The percentage of the light emission from the exciplex to the light emission from the light-emitting layer is greater than 0 percent and less than or equal to 60 percent. The energy after subtracting the energy of light emission from the exciplex from the energy of light emission from the guest material is greater than 0 eV and less than or equal to 0.23 eV.

Abstract: A light-emitting apparatus with low power consumption is provided. A light-emitting apparatus including a first light-emitting device and a first color conversion layer. The first light-emitting device includes an anode, a cathode, and an EL layer positioned between the anode and the cathode. The EL layer includes a layer including a material with a refractive index lower than or equal to 1.75 at 467 nm. The first color conversion layer includes a first substance capable of emission by absorbing light. Light emitted from the first light-emitting device enters the first color conversion layer.

Abstract: To provide a light-emitting element with high emission efficiency and low driving voltage. The light-emitting element includes a guest material and a host material. A LUMO level of the guest material is lower than a LUMO level of the host material. An energy difference between the LUMO level and a HOMO level of the guest material is larger than an energy difference between the LUMO level and a HOMO level of the host material. The guest material has a function of converting triplet excitation energy into light emission. An energy difference between the LUMO level of the guest material and the HOMO level of the host material is larger than or equal to energy of light emission of the guest material.