Light-emitting element, light-emitting device, electronic device, and lighting device

Alight-emitting element comprising:

• an anode;
• a cathode;
• and
• an EL layer positioned between the anode and the cathode,
• wherein the EL layer includes a light-emitting layer, a hole-transport layer, and a hole-injection layer,
• wherein the hole-transport layer is positioned between the light-emitting layer and the anode,
• wherein the hole-injection layer is positioned between the hole-transport layer and the anode,
• wherein the hole-injection layer includes an organic compound having an acceptor property, and
• wherein the hole-transport layer includes an organic compound represented by General Formula (G1),
• wherein R1 to R8 independently represent any one of hydrogen, a hydrocarbon group having 1 to 6 carbon atoms, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms, and
• wherein one of A and B represents a group represented by General Formula (g1) and the other represents any one of hydrogen, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, a hydrocarbon group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms,
• wherein Ar1 and Ar2 independently represent any one of a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms and a group represented by General Formula (g2), and
• wherein a substituent of the substituted aromatic hydrocarbon group having 6 to 60 carbon atoms is any of a hydrocarbon group having 1 to 6 carbon atoms, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms, a dibenzofuranyl group, a dibenzothiophenyl group, a benzonaphthofuranyl group, and a benzonaphthothiophenyl group,
• wherein R11 to R18 independently represent any one of hydrogen, a hydrocarbon group having 1 to 6 carbon atoms, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms, and
• wherein one of Z1 and Z2 is bonded to a nitrogen atom in General Formula (g1) and the other represents any one of hydrogen, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, a hydrocarbon group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms,
• wherein the hole-transport layer includes a first layer, a second layer, and a third layer,
• wherein the first layer is positioned between the hole-injection layer and the second layer,
• wherein the third layer is positioned between the second layer and the light-emitting layer,
• wherein the first layer is in contact with the hole-injection layer,
• wherein the third layer is in contact with the light-emitting layer,
• wherein the first layer includes a first hole-transport material,
• wherein the second layer includes the organic compound,
• wherein the third layer includes a third hole-transport material,
• wherein the light-emitting layer includes a host material and a light-emitting material,
• wherein a HOMO level of the organic compound is deeper than a HOMO level of the first hole-transport material,
• wherein a HOMO level of the host material is deeper than the HOMO level of the organic compound, and
• wherein a difference between the HOMO level of the organic compound and a HOMO level of the third hole-transport material is less than or equal to 0.3 eV.

Alight-emitting element comprising:

• an anode;
• a cathode;
• and
• an EL layer positioned between the anode and the cathode,
• wherein the EL layer includes a light-emitting layer, a hole-transport layer, and a hole-injection layer,
• wherein the hole-transport layer is positioned between the light-emitting layer and the anode,
• wherein the hole-injection layer is positioned between the hole-transport layer and the anode,
• wherein the hole-injection layer includes an organic compound having an acceptor property, and
• wherein the hole-transport layer includes an organic compound represented by General Formula (G1),
• wherein R1 to R8 independently represent any one of hydrogen, a hydrocarbon group having 1 to 6 carbon atoms, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms, and
• wherein one of A and B represents a group represented by General Formula (g1) and the other represents any one of hydrogen, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, a hydrocarbon group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms,
• wherein Ar1 and Ar2 independently represent any one of an unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms, in the case Ar1 and Ar2 have a substituent, the substituent excludes a dinaphthothiophenyl group, and a group represented by General Formula (g2),
• wherein R11 to R18 independently represent any one of hydrogen, a hydrocarbon group having 1 to 6 carbon atoms, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms, and
• wherein one of Z1 and Z2 is bonded to a nitrogen atom in General Formula (g1) and the other represents any one of hydrogen, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, a hydrocarbon group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms,
• wherein the hole-transport layer includes a first layer, a second layer, and a third layer,
• wherein the first layer is positioned between the hole-injection layer and the second layer,
• wherein the third layer is positioned between the second layer and the light-emitting layer,
• wherein the first layer is in contact with the hole-injection layer,
• wherein the third layer is in contact with the light-emitting layer,
• wherein the first layer includes a first hole-transport material,
• wherein the second layer includes the organic compound,
• wherein the third layer includes a third hole-transport material,
• wherein the light-emitting layer includes a host material and a light-emitting material,
• wherein a HOMO level of the organic compound is deeper than a HOMO level of the first hole-transport material,
• wherein a HOMO level of the host material is deeper than the HOMO level of the organic compound, and
• wherein a difference between the HOMO level of the organic compound and a HOMO level of the third hole-transport material is less than or equal to 0.3 eV.

A light-emitting element comprising:

• an anode;
• a cathode;
• and
• an EL layer positioned between the anode and the cathode,
• wherein the EL layer includes a light-emitting layer, a hole-transport layer, and a hole-injection layer,
• wherein the hole-transport layer is positioned between the light-emitting layer and the anode,
• wherein the hole-injection layer is positioned between the hole-transport layer and the anode,
• wherein the hole-injection layer includes an organic compound having an acceptor property, and
• wherein the hole-transport layer includes an organic compound represented by General Formula (G1),
• wherein R1 to R8 independently represent any one of hydrogen, a hydrocarbon group having 1 to 6 carbon atoms, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms,
• wherein one of A and B represents a group represented by General Formula (g1) and the other represents any one of hydrogen, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, a hydrocarbon group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms,
• wherein Ar1 and Ar2 independently represent any one of a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms, in the case Ar1 and Ar2 have a substituent, the substituent excludes a dinaphthothiophenyl group, and a group represented by General Formula (g2),
• wherein R11 to R18 independently represent any one of hydrogen, a hydrocarbon group having 1 to 6 carbon atoms, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms, and
• wherein one of Z1 and Z2 is bonded to a nitrogen atom in General Formula (g1) and the other represents any one of hydrogen, a cyclic hydrocarbon group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, halogen, a haloalkyl group having 1 to 6 carbon atoms, a hydrocarbon group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms,
• wherein the hole-transport layer includes a first layer, a second layer, and a third layer,
• wherein the first layer is positioned between the hole-injection layer and the second layer,
• wherein the third layer is positioned between the second layer and the light-emitting layer,
• wherein the first layer is in contact with the hole-injection layer,
• wherein the third layer is in contact with the light-emitting layer,
• wherein the first layer includes a first hole-transport material,
• wherein the second layer includes the organic compound,
• wherein the third layer includes a third hole-transport material,
• wherein the light-emitting layer includes a host material and a light-emitting material,
• wherein a HOMO level of the organic compound is deeper than a HOMO level of the first hole-transport material,
• wherein a HOMO level of the host material is deeper than the HOMO level of the organic compound, and
• wherein a difference between the HOMO level of the organic compound and a HOMO level of the third hole-transport material is less than or equal to 0.3 eV.