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: An organic semiconductor device with low driving voltage is provided. The organic semiconductor device includes a layer containing an organic compound between a pair of electrodes. The layer containing an organic compound includes a hole-transport region. The hole-transport region includes a first layer and a second layer. The first layer is positioned between the anode and the second layer. When a potential gradient of a surface potential of an evaporated film is set as GSP (mV/nm), a value obtained by subtracting GSP of an organic compound in the second layer from GSP of an organic compound in the first layer is less than or equal to 20 (mV/nm).

Abstract: An organic compound having a hole-transport property and a low refractive index is provided. An organic compound represented by General Formula (G1) shown below is provided. In General Formula (G1), Ar1 represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms in a ring, n represents an integer of 0 or 1, and Ar2 represents an aryl group having 6 to 10 carbon atoms in a ring and includes at least one branched-chain or cyclic alkyl group having 3 to 12 carbon atoms. The total number of carbon atoms of the branched-chain or cyclic alkyl group in Ar2 is more than or equal to 6. R1 to R4 each independently represent an alkyl group having 1 to 6 carbon atoms. R11 to R14 and R21 to R24 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Any one of R15 to R18 and any one of R25 to R28 each represent a bond directly bonded to a nitrogen atom, and the others each independently represent a hydrogen atom or an alkyl group having 1 to 4 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: A light-emitting device with high emission efficiency is provided. The light-emitting device includes a first electrode, a second electrode, and an EL layer positioned between the first electrode and the second electrode. The EL layer includes at least a light-emitting layer, a first layer, a second layer, and a third layer. The first layer is positioned between the first electrode and the light-emitting layer. The third layer is positioned between the first layer and the light-emitting layer. The second layer is positioned between the first layer and the third layer. The first layer includes a first organic compound. The second layer includes a second organic compound. The third layer includes a third organic compound. The ordinary refractive index of the second organic compound is higher than the ordinary refractive index of the first organic and the ordinary refractive index of the third organic compound.

Abstract: A novel organic compound is provided. That is, a novel organic compound that is effective in improving element characteristics and reliability is provided. The organic compound is represented by General Formula (G1) having a dibenzobenzofuroquinoxaline skeleton or a dibenzobenzothienoquinoxaline skeleton. In General Formula (G1), Q represents O or S, at least one of R1 to R12 represents a first group having a substituted or unsubstituted condensed aromatic ring or condensed heteroaromatic ring having 3 to 30 carbon atoms, and the other or others of R1 to R12 each independently represent any one of hydrogen, a halogeno group, a hydroxy group, an amino group, a nitro group, and a group having 1 to 50 carbon atoms.

Abstract: A light-emitting device is provided. The light-emitting device includes an intermediate layer, a first light-emitting unit, and a second light-emitting unit. The intermediate layer includes a region interposed between the first light-emitting unit and the second light-emitting unit. The intermediate layer has a function of supplying an electron to one of the first light-emitting unit and the second light-emitting unit and supplying a hole to the other. The first light-emitting unit includes a first light-emitting layer, the first light-emitting layer includes a first light-emitting material, the second light-emitting unit includes a second light-emitting layer, the second light-emitting layer includes a second light-emitting material, the second light-emitting layer has a first distance from the first light-emitting layer, and the first distance is longer than or equal to 5 nm and shorter than or equal to 65 nm.

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 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: 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: A light-emitting device is provided. The light-emitting device includes an intermediate layer, a first light-emitting unit, and a second light-emitting unit. The intermediate layer includes a region interposed between the first light-emitting unit and the second light-emitting unit. The intermediate layer has a function of supplying an electron to one of the first light-emitting unit and the second light-emitting unit and supplying a hole to the other. The first light-emitting unit includes a first light-emitting layer, the first light-emitting layer includes a first light-emitting material, the second light-emitting unit includes a second light-emitting layer, the second light-emitting layer includes a second light-emitting material, the second light-emitting layer has a first distance from the first light-emitting layer, and the first distance is longer than or equal to 5 nm and shorter than or equal to 65 nm.

Abstract: A light-emitting device with low power consumption is provided. The 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 between the anode and the cathode. The EL layer includes a layer including a material with an ordinary refractive index higher than or equal to 1.50 and lower than 1.75 with respect to light with a wavelength longer than or equal to 455 nm and shorter than or equal to 465 nm. The first color conversion layer includes a first substance that absorbs light and emits light. An ordinary refractive index of the first color conversion layer with respect to light with a wavelength longer than or equal to 455 nm and shorter than or equal to 465 nm is higher than or equal to 1.40 and lower than or equal to 2.10. The first color conversion layer is on an optical path of the light emitted from the first light-emitting device to an outside of the light-emitting apparatus.

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 a light-emitting device with high emission efficiency. Provided is a light-emitting device including an anode, a cathode, and an EL layer positioned therebetween; the EL layer includes a light-emitting layer, a first layer, and a second layer; the first layer is positioned between the anode and the light-emitting layer; the first layer is in contact with the second layer; the second layer contains a monoamine compound having an arylamine structure; a first group, a second group, and a third group are bonded to a nitrogen atom included in the amine in the monoamine compound; the first group is a group including a carbazole structure; the second group is a group including a dibenzofuran structure or a dibenzothiophene structure; the third group includes an aromatic hydrocarbon structure having 6 to 18 carbon atoms or a heteroaromatic hydrocarbon structure having 4 to 26 carbon atoms; and a refractive index of the first layer is lower than a refractive index of the light-emitting layer.

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: 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 unit, and a first layer. The unit is positioned between the first electrode and the second electrode and includes a second layer, a third layer, and a fourth layer. The second layer is positioned between the third layer and the fourth layer and contains a light-emitting material. The third layer is positioned between the second layer and the second electrode, is in contact with the second layer, and contains a first material, and an organometallic complex of an alkali metal or an organometallic complex of an alkaline earth metal. The fourth layer is positioned between the first electrode and the second layer and contains a second material. The first layer is positioned between the first electrode and the unit and contains a second material and a material having an electron acceptor property. The second material has a first refractive index.

Abstract: A novel optical functional device that is highly convenient, useful, or reliable is provided. A light-emitting device includes a first electrode, a second electrode, and an EL layer. The first electrode has a first transmittance; the second electrode overlaps with the first electrode. The second electrode has a second transmittance higher than the first transmittance. The EL layer is interposed between the first electrode and the second electrode and includes a first region, a second region, and a third region. The first region is interposed between the second region and the third region. The second region is interposed between the first electrode and the first region and has a first refractive index. The third region is interposed between the first region and the second electrode and has a second refractive index. The second refractive index is lower than the first refractive index. The EL layer includes a first unit, a second unit, and an intermediate layer.

Abstract: A novel light-emitting device that is highly convenient, useful, or reliable is provided. The light-emitting device includes a function of emitting light, a first electrode, a second electrode, and a unit. The light has the maximum peak at a wavelength (lambda). The second electrode includes a region overlapping with the first electrode. The unit includes a region positioned between the first electrode and the second electrode. The unit includes a first layer, a second layer, and a third layer. The first layer includes a region positioned between the second layer and the third layer. The first layer contains a light-emitting material. The second layer includes a fourth layer and a fifth layer. The fifth layer includes a region positioned between the fourth layer and the first layer. The fourth layer contains a first organic compound. The first organic compound has a first refractive index with respect to light having the wavelength (lambda). The fifth layer is in contact with the fourth layer.

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.