Abstract: A novel compound represented by formula (G1) is provided. In formula (G1), A represents a substituted or unsubstituted condensed aromatic ring having 10 to 30 carbon atoms or a substituted or unsubstituted condensed heteroaromatic ring having 10 to 30 carbon atoms, and Z1 to Z3 each independently have a structure represented by formula (Z-1) or (Z-2). In formula (Z-1), X1 and X2 each independently represent any one of an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a cycloalkyl group having a bridge structure and having 7 to 10 carbon atoms, and a trialkylsilyl group having 3 to 12 carbon atoms. In addition, Ar1 to Ar4 each independently represent a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms, and at least one of Ar1 to Ar4 has the same substituent as X1 or X2.

Abstract: An EL layer includes a low refractive index layer comprising an organic compound and a light-emitting layer comprising a light-emitting substance. The organic compound has an ordinary refractive index of 1.50 to 1.75 with respect to light at 455 nm to 465 nm, or an ordinary refractive index of 1.45 to 1.70 with respect to light at 633 nm. Given that a wavelength corresponding to an intensity 1/e times a maximum peak intensity in an emission spectrum of the light-emitting substance is ?n, a shortest ?n in a range of wavelengths longer than a maximum peak wavelength ?max of the light-emitting substance is ?1, and a longest ?n in a range of wavelengths shorter than ?max is ?2, a difference between ?1 and ?2 is greater than or equal to 5 nm and less than or equal to 45 nm.

Abstract: An organic semiconductor device with low driving voltage is provided. The light-emitting device includes an anode, a cathode, and an EL layer between the anode and the cathode. The EL layer includes a hole-transport layer and alight-emitting layer. The hole-transport layer is positioned between the anode and the light-emitting layer. The hole-transport layer is not in contact with the anode. The hole-transport layer includes a transport layer material for a light-emitting device and the GSP_slope that is a potential gradient of a surface potential of an evaporated film of the material is higher than or equal to 20 (mV/nm).

Abstract: A light-emitting element having high emission efficiency which includes a fluorescent material as a light-emitting substance is provided. A light-emitting element includes a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a light-emitting layer. The light-emitting layer includes a host material and a guest material. The host material has a difference of more than 0 eV and less than or equal to 0.2 eV between a singlet excitation energy level and a triplet excitation energy level. The guest material is capable of emitting fluorescence. The triplet excitation energy level of the host material is higher than a triplet excitation energy level 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: A light-emitting device, an electronic device, and a display device each consume less power are provided. The light-emitting device includes a first light-emitting element, a second light-emitting element, and a third light-emitting element that share an EL layer. The EL layer includes a layer containing a light-emitting material that emits blue fluorescence and a layer containing a light-emitting material that emits yellow or green phosphorescence. Light emitted from the second light-emitting element enters a color filter layer or a second color conversion layer, and light emitted from the third light-emitting element enters a first color conversion layer.

Abstract: A light-emitting device with low driving voltage and favorable reliability is provided. The light-emitting device includes an electron-injection layer between a cathode and a light-emitting layer. The electron-injection layer is a mixed film of a metal and an organic compound having a function of interacting with the metal as a tridentate or tetradentate ligand, and the metal atom and the organic compound form SOMO.

Abstract: An organic compound that enables provision of a light-emitting device with high emission efficiency and high reliability is provided. An organic compound represented by General Formula (G1-1) below is provided. Note that in General Formula (G1-1) below, R1 to R10 each independently represent any one of hydrogen, an alkyl group having 3 to 10, inclusive, carbon atoms, and a substituted or unsubstituted cycloalkyl group having 3 to 10, inclusive, carbon atoms, and Ar1 and Ar2 each independently represent an aromatic hydrocarbon group having 6 to 13, inclusive, carbon atoms with a substituent. The Ar1 and the Ar2 each include, as the substituent, one or more of a cycloalkyl group having 3 to 12, inclusive, carbon atoms and a cycloalkyl group having a bridge structure and having 7 to 10, inclusive, carbon atoms.

Abstract: A light-emitting element including a fluorescent material as a light-emitting material and having high emission efficiency is provided. The light-emitting element includes a pair of electrodes and an EL layer provided between the pair of electrodes. The EL layer includes a host material and a guest material. The host material is capable of exhibiting thermally activated delayed fluorescence at room temperature. The guest material is capable of exhibiting fluorescence. The second triplet excitation energy level of the guest material is higher than or equal to the lowest singlet excitation energy level of the guest material.

Abstract: A light-emitting element includes a light-emitting layer including a guest, an n-type host and a p-type host between a pair of electrodes, where the difference between the energy difference between a triplet excited state and a ground state of the n-type host (or p-type host) and the energy difference between a triplet excited state and a ground state of the guest is 0.15 eV or more. Alternatively, in such a light-emitting element, the LUMO level of the n-type host is higher than the LUMO level of the guest by 0.1 eV or more, or the HOMO level of the p-type host is lower than the HOMO level of the guest by 0.1 eV or more.

Abstract: A novel light-emitting device with high emission efficiency is provided. The light-emitting device includes a first electrode, a second electrode, an EL layer, and an insulating layer. The EL layer is positioned between the first electrode and the second electrode. The EL layer includes at least a light-emitting layer, an electron-transport layer, and an electron-injection layer. The electron-transport layer is positioned over the light-emitting layer. The insulating layer is in contact with an end portion of the light-emitting layer and an end portion of the electron-transport layer. The electron-injection layer is positioned over the electron-transport layer. The electron-injection layer includes an alkali metal compound and a reducing agent.

Abstract: An organic compound having a hole-transport property and a low refractive index is provided. An organic compound represented by General Formula (G1) is provided. In the formula, Ar12 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 having 3 to 12 carbon atoms in Ar12 is 6 to 36. Ar11 and Ar21 each represent a substituted or unsubstituted arylene group having 6 to 13 carbon atoms in a ring. Ar22 represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms in a ring. In addition, n and m each independently represent an integer of 0 or 1. Ar1 represents a phenyl group including at least one alkyl group having 1 to 6 carbon atoms. Ar2 represents a phenyl group including at least one alkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 4 carbon atoms.

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 element containing a light-emitting material with high light emission efficiency is provided. The light-emitting element includes a high molecular material and a guest material. The high molecular material includes at least a first high molecular chain and a second high molecular chain. The guest material has a function of exhibiting fluorescence or converting triplet excitation energy into light emission. The first high molecular chain and the second high molecular chain each include a first skeleton, a second skeleton, and a third skeleton, and the first skeleton and the second skeleton are bonded to each other through the third skeleton. The first high molecular chain and the second high molecular chain have a function of forming an excited complex.

Abstract: Emission efficiency of a light-emitting element is improved. The light-emitting element has a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first light-emitting layer and a second light-emitting layer. The first light-emitting layer includes a fluorescent material and a host material. The second light-emitting layer includes a phosphorescent material, a first organic compound, and a second organic compound. An emission spectrum of the second light-emitting layer has a peak in a yellow wavelength region. The first organic compound and the second organic compound form an exciplex.

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: A light-emitting device with high emission efficiency is provided. The light-emitting device includes an EL layer and a light-transmitting electrode. The EL layer includes a light-emitting layer and a low refractive index layer. The low refractive index layer is positioned between the light-emitting layer and the light-transmitting electrode. A cap layer is in contact with a surface of the light-transmitting electrode on the side opposite to the EL layer. The cap layer includes a high refractive index material having an ordinary refractive index of higher than or equal to 1.90 and lower than or equal to 2.40 and an ordinary extinction coefficient of higher than or equal to 0 and lower than or equal to 0.01. The low refractive index layer includes a low refractive index material having an ordinary refractive index of higher than or equal to 1.60 and lower than or equal to 1.70.

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 indices of the first organic compound and the third organic compound.

Abstract: A light-emitting device with high emission efficiency and reliability is provided. The light-emitting device includes first and second light-emitting units. The first light-emitting unit includes a first light-emitting layer; the first light-emitting layer includes a first material and a second material; the first material has a function of converting triplet excitation energy into light emission; the second material has a function of converting singlet excitation energy into light emission and includes a luminophore and five or more protecting groups; the luminophore is a condensed aromatic ring or a condensed heteroaromatic ring; the five or more protecting groups each independently have any one of an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 12 carbon atoms; and light emission is obtained from the second material.

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.