Abstract:
To provide a light-emitting element with an improved reliability, a light-emitting element with a high current efficiency (or a high quantum efficiency), and a novel dibenzo[f,h]quinoxaline derivative that is favorably used in a light-emitting element which is one embodiment of the present invention. A light-emitting element includes an EL layer between an anode and a cathode. The EL layer includes a light-emitting layer; the light-emitting layer contains a first organic compound having an electron-transport property and a hole-transport property, a second organic compound having a hole-transport property, and a light-emitting substance; the combination of the first organic compound and the second organic compound forms an exciplex; the HOMO level of the first organic compound is lower than the HOMO level of the second organic compound; and a difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is less than or equal to 0.4 eV.
Abstract:
A novel phosphorescent organometallic iridium complex is provided in which a coordination position of a ligand with respect to a metal can be controlled in synthesis. A novel phosphorescent organometallic iridium complex is provided which can keep high quantum efficiency and can emit phosphorescence in the blue to green wavelength region. A phosphorescent organometallic iridium complex which includes a structure represented by General Formula (G1) and whose ligand is a 4H-1,2,4-triazole compound which has an unsubstituted phenyl group at the 3-position, a substituted or unsubstituted phenyl group at the 4-position, and a phenyl group at the 5-position. In the phenyl group at the 5-position, an alkyl group is bonded to at least one of the ortho-positions, and the other of the ortho-positions, the meta-positions, and the para-position are substituted or unsubstituted.
Abstract:
A novel heterocyclic compound is provided. In particular, a novel heterocyclic compound which can improve the element characteristics of the light-emitting element is provided. The heterocyclic compound is represented by a general formula (G1) DBqAr1nAr2-A (G1) in which a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group and a substituted or unsubstituted benzobisbenzofuranyl group are bonded to each other via a substituted or unsubstituted arylene group. In the general formula (G1), DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group, Ar1 represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, n represents 0 or 1, Ar2 represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and A represents a substituted or unsubstituted benzobisbenzofuranyl group. When the arylene group represented by Ar1 and Ar2 has substituents, the substituents may be bonded to each other to form a ring.
Abstract:
A novel heterocyclic compound is provided. In particular, a novel heterocyclic compound which can improve the element characteristics of the light-emitting element is provided. The heterocyclic compound is represented by a general formula (G1) DBq-(Ar1)-n-Ar2-A (G1) in which a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group and a substituted or unsubstituted benzobisbenzofuranyl group are bonded to each other via a substituted or unsubstituted arylene group. In the general formula (G1), DBq represents a substituted or unsubstituted dibenzo [f,h] quinoxalinyl group, Ar1 represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, n represents 0 or 1, Ar2 represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and A represents a substituted or unsubstituted benzobisbenzofuranyl group. When the arylene group represented by Ar1 and Ar2 has substituents, the substituents may be bonded to each other to form a ring.
Abstract:
A novel phosphorescent organometallic iridium complex is provided in which a coordination position of a ligand with respect to a metal can be controlled in synthesis. A novel phosphorescent organometallic iridium complex is provided which can keep high quantum efficiency and can emit phosphorescence in the blue to green wavelength region. A phosphorescent organometallic iridium complex which includes a structure represented by General Formula (G1) and whose ligand is a 4H-1,2,4-triazole compound which has an unsubstituted phenyl group at the 3-position, a substituted or unsubstituted phenyl group at the 4-position, and a phenyl group at the 5-position. In the phenyl group at the 5-position, an alkyl group is bonded to at least one of the ortho-positions, and the other of the ortho-positions, the meta-positions, and the para-position are substituted or unsubstituted.
Abstract:
An organometallic complex that has high emission efficiency and high heat resistance and emits blue light is provided as a novel substance. In a light-emitting element including a light-emitting layer between a pair of electrodes, the light-emitting layer includes an organometallic complex, and the organometallic complex includes a central metal and two types of ligands coordinated to the central metal. One of the two types of ligands includes a triazole skeleton including nitrogen bonded to the central metal, and the other includes a nitrogen-containing five-membered heterocyclic skeleton including carbene carbon bonded to the central metal and nitrogen bonded to carbene carbon.
Abstract:
The organic compound represented by Formula G1 below has a structure in which the 2-position of a dibenzoquinazoline ring is directly, or via one or more arylene groups, bonded to a skeleton with a hole-transport property. In the formula, n represents any of 0 to 3, m represents 1 or 2, A represents a single bond, or a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, B represents a ring having a substituted or unsubstituted dibenzofuran skeleton, a substituted or unsubstituted dibenzothiophene skeleton, or a substituted or unsubstituted carbazole skeleton, and each of R1 to R14 independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.
Abstract:
An object is to provide a novel organometallic complex. Another object is to provide an organometallic complex exhibiting green to blue phosphorescence. Another object is to provide an organometallic complex having deep HOMO and exhibiting green to blue phosphorescence. Another object is to provide a light-emitting element with high emission efficiency. Another object is to provide a light-emitting element exhibiting green to blue phosphorescence and having low drive voltage. To provide an organometallic complex which includes a 1,2,4-triazole skeleton and in which an N-carbazolyl group is bonded to the 3-position of the 1,2,4-triazole skeleton via a phenylene group, a phenyl group is bonded to the 4-position of the 1,2,4-triazole skeleton, the 2-position of the 1,2,4-triazole skeleton coordinates to iridium, and the phenylene group is bonded to the iridium. To provide a light-emitting element including the organometallic complex as an emission center.
Abstract:
A light-emitting element with high emission efficiency is provided. In addition, a light-emitting element having a low driving voltage is provided. Furthermore, a novel compound which can be used for a transport layer, a host material, or a light-emitting material of a light-emitting element is provided. A novel compound including a benzothienopyrimidine skeleton is provided. Furthermore, a light-emitting element including a pair of electrodes and an EL layer sandwiched between the pair of electrodes is provided. The EL layer contains a substance including the benzothienopyrimidine skeleton.