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 display device having a high display quality is provided. A display device that can perform desired display without image data conversion is provided. The display device includes a first pixel. The first pixel includes a first light-emitting element, a color conversion layer, and a first memory circuit. The first light-emitting element exhibits blue light. The color conversion layer has a function of converting light emitted by the first light-emitting element into light having a longer wavelength. A first image signal and a first correction signal are supplied to the first pixel. The first memory circuit has a function of retaining the first correction signal and a function of adding the first correction signal to the first image signal. The first pixel has a function of displaying an image using the first image signal and the first correction signal.

Abstract: An organic semiconductor device that can achieve high resolution and favorable reliability is provided. The organic semiconductor device is one of a plurality of light-emitting devices formed over an insulating layer, which includes a first electrode, a second electrode, and an organic compound layer. The organic compound layer is positioned between the first electrode and the second electrode. The organic compound layer includes a layer containing a first compound. When differential scanning calorimetry is performed on the first compound in such a manner that a cooling step is performed from the state in which the first compound is melted in a first heating step and a second heating step is successively performed, an exothermic peak is not observed in the cooling step and an exothermic peak and a melting point peak are not observed in the second heating step.

Abstract: A novel organometallic complex with high heat resistance is provided. The organometallic complex includes a structure represented by General Formula (G1) below, in which iridium and a ligand are included, the ligand includes a pyrazine skeleton, iridium is bonded to nitrogen at the 1-position of the pyrazine skeleton, an aryl group including a cyano group as a substituent is bonded at the 5-position of the pyrazine skeleton, and each of the 3-position and the 6-position of the pyrazine skeleton is independently bonded to any one of hydrogen, an alkyl group, and an alkoxy group. (In the formula, A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. In addition, Ar represents an aryl group having 6 to 25 carbon atoms and at least one cyano group as a substituent. Each of R1 and R2 independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms.

Abstract: To provide a storage battery including a carbon-based material. To provide a graphene compound film having desired ion conductivity and mechanical strength while preventing direct contact between electrodes in a storage battery. To achieve long-term reliability. A lithium-ion storage battery includes a positive electrode, a negative electrode, an exterior body, and a separator between the positive electrode and the negative electrode. In the lithium-ion storage battery, one of the positive electrode and the negative electrode is wrapped in a first film, and the positive electrode, the negative electrode, and the separator are stored in the exterior body. The first film may include a first region in which the first film includes a first functional group. The first film may further include a second region in which the first film includes a second functional group different from the first functional group. The first film may be a graphene compound film.

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: A novel compound is provided. The compound is represented by General Formula (G1). In General formula (G1), each of Z1 to Z4 independently has a structure represented by General formula (Z-1) or General formula (Z-2). In General Formula (Z-1), each of X1 and X2 independently represents 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 with a bridge structure having 7 to 10 carbon atoms, and a trialkylsilyl group having 3 to 12 carbon atoms. Moreover, each of Ar1 and Ar2 independently represents an aromatic hydrocarbon group having 6 to 13 carbon atoms, and at least one of Ar1 and Ar2 includes a substituent that is the same as X1.

Abstract: A light-emitting element includes an EL layer between a pair of electrodes. The EL layer contains a first compound and a second compound. The first compound is a phosphorescent iridium metal complex having a LUMO level of greater than or equal to ?3.5 eV and less than or equal to ?2.5 eV, and the second compound is an organic compound having a pyrimidine skeleton. The light-emitting element includes an EL layer between a pair of electrodes. The EL layer contains a first compound and a second compound. The first compound is a phosphorescent iridium metal complex having a diazine skeleton, and the second compound is an organic compound having a pyrimidine skeleton.

Abstract: A novel organic compound having an emission spectrum peak at a wavelength longer than 850 nm and an absorption spectrum peak at a wavelength longer than 600 nm is provided. The organic compound is represented by General Formula (G1). In General Formula (G1), Ar1 to Ar4 each independently represent an aryl group having 6 to 13 carbon atoms in a ring. R1 to R8 each independently represent anyone of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aryl group having 6 to 13 carbon atoms in a ring, and a heteroaryl group having 3 to 13 carbon atoms in a ring. Q1 and Q2 each independently represent a group having a carbazole skeleton or a group having a triarylamine skeleton and having 18 to 30 carbon atoms in a ring. Furthermore, m and n each independently represent 0 or 1.

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 Förster mechanism, which is one of mechanisms of intermolecular energy transfer. Efficient energy transfer by Förster 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 novel organic compound is provided. Alternatively, an organic compound that emits light with favorable chromaticity is provided. Alternatively, an organic compound that emits blue light with favorable chromaticity is provided. Alternatively, a light-emitting element with favorable emission efficiency is provided. Alternatively, an organic compound with an excellent carrier-transport property is provided. The organic compound includes any of a substituted or unsubstituted dibenzofurobisbenzofuran skeleton, a substituted or unsubstituted dibenzothienobisbenzothiophene skeleton, a substituted or unsubstituted benzobisbenzothienobenzofuran skeleton, and a substituted or unsubstituted dibenzothienobisbenzofuran skeleton and one or two amino groups.

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: A triarylamine derivative represented by a general formula (G1) given below is provided. Note that in the formula, Ar represents either a substituted or unsubstituted phenyl group or a substituted or unsubstituted biphenyl group; ? represents a substituted or unsubstituted naphthyl group; ? represents either hydrogen or a substituted or unsubstituted naphthyl group; n and m each independently represent 1 or 2; and R1 to R8 each independently represent any of hydrogen, an alkyl group having 1 to 6 carbon atoms, or a phenyl group.

Abstract: A novel light-emitting device is provided. Alternatively, a light-emitting device with favorable emission efficiency is provided. Alternatively, a light-emitting device with a favorable lifetime is provided. Alternatively, a light-emitting device with a low driving voltage is provided. Provided is a light-emitting device including an anode, a cathode, and a layer including an organic compound that is positioned between the anode and the cathode, in which the layer including the organic compound includes a first layer, a second layer, and a light-emitting layer in this order from the anode side, the first layer includes a first substance and a second substance, the second layer includes a third substance, the first substance is an organic compound a HOMO level of which is higher than or equal to -5.8 eV and lower than or equal to -5.

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: A light-emitting element which has low driving voltage and high emission efficiency is provided. The light-emitting element includes, between a pair of electrodes, a hole-transport layer and a light-emitting layer over the hole-transport layer. The light-emitting layer contains a first organic compound having an electron-transport property, a second organic compound having a hole-transport property, and a light-emitting third organic compound converting triplet excitation energy into light emission. A combination of the first organic compound and the second organic compound forms an exciplex. The hole-transport layer contains at least a fourth organic compound whose HOMO level is lower than or equal to that of the second organic compound and a fifth organic compound whose HOMO level is higher than that of the second organic compound.

Abstract: To provide a light-emitting device with high emission efficiency and high reliability. A light-emitting layer of the light-emitting device includes a first substance emitting light from a doublet excited state based on f-d transition and a second substance that is a fluorescent substance. The longest-wavelength absorption edge among absorption edges in the absorption spectrum of the first substance is positioned at a wavelength shorter than the wavelength of the longest-wavelength absorption edge among absorption edges in the absorption spectrum of the second substance. The first substance has a short exciton lifetime and high exciton generation efficiency, and efficient energy transfer occurs between the first substance and the second substance; thus, the light-emitting device can have high emission efficiency and high reliability.

Abstract: A light-emitting device with high emission efficiency is provided. A light-emitting device with a low driving voltage is provided. The light-emitting device includes a first electrode, a first layer over the first electrode, a second layer over the first layer, a light-emitting layer over the second layer, and a second electrode over the light-emitting layer. The first layer includes a first organic compound, and the second layer includes a second organic compound. The proportion of carbon atoms forming bonds by the sp3 hybrid orbitals to the total number of carbon atoms in the first organic compound is higher than or equal to 23 percent and lower than or equal to 55 percent. The second organic compound contains fluorine.

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.