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 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: A novel organic compound represented by General Formula (G1) is provided. In General Formula (G1), X1 and X2 each independently represent a secondary or tertiary alkyl group having 3 to 6 carbon atoms and having a branched carbon atom which is bonded to a phenyl group. In addition, Ar1 represents a substituted or unsubstituted condensed aromatic ring skeleton having 10 to 60 carbon atoms and composed of two or more rings or a substituted or unsubstituted condensed heteroaromatic ring skeleton having 8 to 60 carbon atoms and composed of two or more rings. Furthermore, Ar2 represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms. Moreover, n represents any of 1 to 3, and in the case where n is 2 or more, two or more groups bonded to Ar1 may be identical or different.

Abstract: A novel organic compound with favorable thermophysical properties is provided. An organic compound represented by General Formula (G1) is provided. At least one of X1 to X5 is a secondary or tertiary alkyl group having 3 to 6 carbon atoms in which a carbon atom bonded to a phenyl group branches. Each of R1 to R7 is independently any of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, and an unsubstituted or alkyl-substituted aryl group having 6 to 13 carbon atoms. Ar1 represents a substituted or unsubstituted condensed heteroaromatic ring skeleton having 8 to 60 carbon atoms and composed of two or more aromatic rings, and Ar2 represents a substituted or unsubstituted aryl group having 6 to 25 carbon atoms. Furthermore, n is any of 1 to 3.

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 composite material including an organic compound and an inorganic compound and having a high carrier-transport property is provided. A composite material having a high carrier-injection property to an organic compound is provided. A composite material in which light absorption due to charge transfer interaction is unlikely to occur is provided. A light-emitting element having high emission efficiency is provided by including the composite material. A light-emitting element having a low drive voltage is provided. A light-emitting element having a long lifetime is provided. A composite material including a heterocyclic compound having a dibenzothiophene skeleton or a dibenzofuran skeleton and an inorganic compound exhibiting an electron-accepting property with respect to the heterocyclic compound is provided.

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 is provided. An organic compound that emits light with excellent chromaticity is provided. An organic compound in which one or two groups represented by the following general formula (g1) are bonded to any one of a naphthobisbenzofuran skeleton, a naphthobisbenzothiophene skeleton, and a naphthobenzofuranobenzothiophene skeleton is provided.

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: An object is to provide a light-emitting element with a favorable lifetime.

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 light-emitting element with high emission efficiency and high reliability is provided. The light-emitting element includes a light-emitting layer containing a first organic compound, a second organic compound, and a guest material. The first organic compound has a nitrogen-containing six-membered heteroaromatic skeleton. In the light-emitting layer, the weight ratio of an organic compound having a nitrogen-containing five-membered heterocyclic skeleton with an NH group, a secondary amine skeleton with an NH group, or a primary amine skeleton with an NH group to the first organic compound is less than or equal to 0.03, or alternatively, the weight ratio of the organic compound having a nitrogen-containing five-membered heterocyclic skeleton with an NH group, a secondary amine skeleton with an NH group, or a primary amine skeleton with an NH group to the second organic compound is less than or equal to 0.01.

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 object is to provide a light-emitting element having high light-emission efficiency by provision of a novel fluorene derivative as represented by General Formula (G1) below In the formula, R1 to R8 independently represent any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted biphenyl group. Further, ?1 to ?4 independently represent any of a substituted or unsubstituted arylene group having 6 to 12 carbon atoms. Furthermore, Ar1 and Ar2 independently represent any of an aryl group having 6 to 13 carbon atoms in a ring and Ar3 represents an alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. J, k, m, and n each independently represent 0 or 1.

Abstract: An object is to provide a light-emitting element with high emission efficiency which includes a novel carbazole derivative that has a wide energy gap and can be used for a transport layer or a host material in a light-emitting element. A carbazole derivative in which the 4-position of dibenzothiophene or dibenzofuran is bonded to the 2- or 3-position of carbazole has been able to be provided by use of the carbazole derivative. Further, a light-emitting element having high emission efficiency has been able to be provided by use of the carbazole derivative.

Abstract: A physical property prediction method that allows anyone to predict a physical property of an organic compound easily and accurately is provided. A physical property prediction system that allows anyone to predict a physical property of an organic compound easily and accurately is provided. Provided are a physical property prediction method including the step of learning a correlation between a molecular structure and a physical property of an organic compound and the step of predicting the target physical property value from the molecular structure of an object substance, and a physical property prediction system. A plurality of kinds of fingerprinting methods are used at the same time as notation methods of the molecular structure of the organic compound.

Abstract: A light-emitting element that contains a fluorescent compound, which has high efficiency is provided. A light-emitting element in which the proportion of delayed fluorescence to the total light emitted from the light-emitting element is higher than that in a conventional light-emitting element is provided. Emission efficiency of the light-emitting element containing a fluorescent compound can be improved by increasing the probability of TTA caused by an organic compound in an EL layer, converting energy of triplet excitons, which does not contribute to light emission, into energy of singlet excitons, and making the fluorescent compound emit light by energy transfer of the singlet excitons.

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 light-emitting element with high emission efficiency and high reliability is provided. The light-emitting element includes a light-emitting layer containing a first organic compound, a second organic compound, and a guest material. The first organic compound has a nitrogen-containing six-membered heteroaromatic skeleton. In the light-emitting layer, the weight ratio of an organic compound having a nitrogen-containing five-membered heterocyclic skeleton with an NH group, a secondary amine skeleton with an NH group, or a primary amine skeleton with an NH group to the first organic compound is less than or equal to 0.03, or alternatively, the weight ratio of the organic compound having a nitrogen-containing five-membered heterocyclic skeleton with an NH group, a secondary amine skeleton with an NH group, or a primary amine skeleton with an NH group to the second organic compound is less than or equal to 0.01.