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 object is to provide a highly reliable display unit having a function of sensing light. The display unit includes a light-receiving device and a light-emitting device. The light-receiving device includes an active layer between a pair of electrodes. The light-emitting device includes a hole-injection layer, a light-emitting layer, and an electron-transport layer between a pair of electrodes. The light-receiving device and the light-emitting device share one of the electrodes, and may further share another common layer between the pair of electrodes. The hole-injection layer is in contact with an anode and contains a first compound and a second compound. The electron-transport property of the electron-transport layer is low; hence, the light-emitting layer is less likely to have excess electrons. Here, the first compound is the material having a property of accepting electrons from the second compound.

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: An object is to provide a highly reliable display unit having a function of sensing light. The display unit includes a light-receiving device and a light-emitting device. The light-receiving device includes an active layer between a pair of electrodes. The light-emitting device includes a hole-injection layer, a light-emitting layer, and an electron-transport layer between a pair of electrodes. The light-receiving device and the light-emitting device share one of the electrodes, and may further share another common layer between the pair of electrodes. The hole-injection layer is in contact with an anode and contains a first compound and a second compound. The electron-transport property of the electron-transport layer is low; hence, the light-emitting layer is less likely to have excess electrons. Here, the first compound is the material having a property of accepting electrons from the second compound.

Abstract: An organic compound that easily exhibits thermally activated delayed fluorescence (TADF) is provided. An organic compound represented by General Formula (G1) is provided. In General Formula (G1), R1 to R8 are each independently any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms, and a substituted or unsubstituted diarylamino group; at least one of R1 to R8 is a substituted or unsubstituted diarylamino group; a is a substituted or unsubstituted phenylene group; n is an integer of 0 to 4; and A represents a substituted or unsubstituted benzofuropyrimidine skeleton or benzothienopyrimidine skeleton.

Abstract: To increase emission efficiency of a fluorescent light-emitting element by efficiently utilizing a triplet exciton generated in a light-emitting layer. The light-emitting layer of the light-emitting element includes at least a host material and a guest material. The triplet exciton generated from the host material in the light-emitting layer is changed to a singlet exciton by triplet-triplet annihilation (TTA). The guest material (fluorescent dopant) is made to emit light by energy transfer from the singlet exciton. Thus, the emission efficiency of the light-emitting element is improved.

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: To provide a light-emitting element having high luminous efficiency and to provide a light-emitting device and an electronic device which consumes low power and is driven at low voltage, a carbazole derivative represented by the general formula (1) is provided. In the formula, ?1, ?2, ?3, and ?4 each represent an arylene group having less than or equal to 13 carbon atoms; Ar1 and Ar2 each represent an aryl group having less than or equal to 13 carbon atoms; R1 represents any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, and a substituted or unsubstituted biphenyl group; and R2 represents any of an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, and a substituted or unsubstituted biphenyl group. In addition, l, m, and n are each independently 0 or 1.

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: To increase emission efficiency of a fluorescent light-emitting element by efficiently utilizing a triplet exciton generated in a light-emitting layer. The light-emitting layer of the light-emitting element includes at least a host material and a guest material. The triplet exciton generated from the host material in the light-emitting layer is changed to a singlet exciton by triplet-triplet annihilation (TTA). The guest material (fluorescent dopant) is made to emit light by energy transfer from the singlet exciton. Thus, the emission efficiency of the light-emitting element is improved.

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 display device having a long lifetime is provided. The display device includes a first light-emitting device and a second light-emitting device. The first light-emitting device includes a first electrode and a common electrode. The second light-emitting device includes a second electrode and a common electrode. The first light-emitting device includes a first light-emitting layer and an electron-transport layer in this order from a side of one of the first electrode and the common electrode which functions as an anode. The second light-emitting device includes a second light-emitting layer between the second electrode and the common electrode. The first light-emitting layer contains a first organic compound emitting light of a first color. The second light-emitting layer contains a second organic compound emitting light of a second color. The electron-transport layer contains a third organic compound and a first substance. The third organic compound is an electron-transport material.

Abstract: A novel organic compound is provided. Alternatively, an organic compound that exhibits light emission with favorable chromaticity is provided. Alternatively, an organic compound that exhibits blue light emission with favorable chromaticity is provided. Alternatively, an organic compound with favorable emission efficiency is provided. Alternatively, an organic compound having a high carrier-transport property is provided. Alternatively, an organic compound with favorable reliability is provided. An organic compound including at least one amino group in which any one of a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, and a substituted or unsubstituted carbazolyl group is boneded to any one of a substituted or unsubstituted naphthobisbenzofuran skeleton, a substituted or unsubstituted naphthobisbenzothiophene skeleton, and a substituted or unsubstituted naphthobenzofuranobenzothiophene skeleton is provided.

Abstract: A light-emitting device with a long lifetime is provided. In a light-emitting device that includes an EL layer between a pair of electrodes, a light-emitting layer included in the EL layer has a functional stacked-layer structure, whereby the efficiency and reliability of the light-emitting device can be increased.

Abstract: A display device having a long lifetime is provided. A large-sized display device is provided. A display device includes a first light-emitting device and a second light-emitting device. The first light-emitting device includes a hole-injection layer, a first light-emitting layer, and an electron-transport layer. The second light-emitting device includes a second light-emitting layer. The hole-injection layer contains a first compound and a second compound. The first light-emitting layer contains a third compound that emits light of a first color. The second light-emitting layer contains a fourth compound that emits light of a second color. The electron-transport layer contains a fifth compound. The first compound has a property of accepting electrons from the second compound. The second compound has a HOMO level higher than or equal to ?5.7 eV and lower than or equal to ?5.4 eV. The fifth compound has a HOMO level higher than or equal to ?6.

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 light-emitting device that is highly convenient, useful, or reliable is provided. An organic compound in which a substituted or unsubstituted naphtho[2,3-c]carbazolyl group or a substituted or unsubstituted benzo[c]naphtho[2,3-g]carbazolyl group is bonded to a substituted or unsubstituted 9H-carbazolyl group or a substituted or unsubstituted anthryl group through a substituted or unsubstituted arylene group. The arylene group has 6 to 13, inclusive, carbon atoms.

Abstract: A display panel is provided. The display panel includes a display region, an insulating film, and a sealing film; the display region includes a pixel; and the pixel includes a display element and a color conversion layer. The insulating film covers the display element, the sealing film includes a region, the color conversion layer is sandwiched between the region and the insulating film, and the sealing film includes a region that is on the outside of the display region and in contact with the insulating film. The display element includes a first layer, a second layer, a third layer, and a fourth layer. The first layer contains a first material and a second material, the second layer contains a third material, the third layer contains a light-emitting material and a fourth material, the fourth layer contains a fifth material and a sixth material, the first material has a HOMO level higher than or equal to ?5.7 eV and lower than or equal to ?5.

Abstract: A novel organic compound is provided. Alternatively, an organic compound that exhibits light emission with favorable chromaticity is provided. Alternatively, an organic compound that exhibits blue light emission with favorable chromaticity is provided. Alternatively, an organic compound with favorable emission efficiency is provided. Alternatively, an organic compound having a high carrier-transport property is provided. Alternatively, an organic compound with favorable reliability is provided. An organic compound including at least one amino group in which any one of a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, and a substituted or unsubstituted carbazolyl group is bonded to any one of a substituted or unsubstituted naphthobisbenzofuran skeleton, a substituted or unsubstituted naphthobisbenzothiophene skeleton, and a substituted or unsubstituted naphthobenzofuranobenzothiophene skeleton is provided.

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.