Luminescence device and display apparatus

Abstract

In a luminescence device formed of one or plural layers of organic film between a cathode and an anode, at least one layer is a luminescence layer, and a luminescence molecule of a metal coordination compound having a basic structure represented by formula (1) ML m L′ n and having a substituent on at least one of cyclic groups incorporated as a guest in a host material at a concentration of at least 8 wt. %, which is higher than a concentration at which a luminescence molecule of a similar structure but having no substituent exhibits a maximum luminescence efficiency to form the luminescence layer. As a result, a high-efficiency luminescence device is provided, which is less liable to cause concentration extinction even when a luminescence molecule is contained at a high concentration relative to the host material in the luminescence layer.

1 . An organic luminescence device, comprising: a pair of electrodes each disposed on a substrate, and at least one luminescence layer comprising an organic compound disposed between the electrodes; 
 wherein the luminescence layer comprises a non-luminescent first organic compound and a phosphorescent second organic compound represented by formula (1) shown below, and the second organic compound is present at a concentration of at least 8 wt. % in the luminescence layer:      ML m L′ n    (1),    wherein M is a metal atom of Ir, Pt, Rh or Pd; L and L′ are mutually different bidentate ligands; m is 1, 2 or 3; n is 0, 1 or 2 with the proviso that m+n is 2 or 3; a partial structure ML m  is represented by formula (2) shown below and a partial structure ML′ n  is represented by formula (3), (4) or (5) shown below:                          wherein N and C are nitrogen and carbon atoms, respectively; A and A′ are respectively a cyclic group capable of having a substituent and bonded to the metal atom M via the carbon atom; B, B′ and B″ are respectively a cyclic group represented by a formula of (6)-(14) shown below capable of having a substituent and connected to the metal atom M via the nitrogen atom:                                            {wherein the substituent is selected from a halogen atom, a cyano group, a nitro group, a trialkylsilyl group (of which the alkyl groups are independently a linear or branched alkyl group having 1 to 8 carbon atoms), a linear or branched alkyl group having 1 to 20 carbon atoms (of which the alkyl group can include one or non-neighboring two or more methylene groups that can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C— and the alkyl group can include a hydrogen atom that can be replaced with a fluorine atom), or an aromatic cyclic group capable of having a substituent (of which the substituent is selected from a halogen atom, a cyano group, a nitro group, a linear or branched alkyl group having 1 to 20 carbon atoms (of which the alkyl group can include one or non-neighboring two or more methylene groups that can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C— and the alkyl group can include a hydrogen atom that can be replaced with a fluorine atom)};    A and B, and A′ and B′ are respectively bonded to each other via a covalent bond;    E and G are independently a linear or branched alkyl group having 1 to 20 carbon atoms (of which the alkyl group can include a hydrogen atom that can be optionally replaced with a fluorine atom), or an aromatic cyclic group capable of having a substituent (of which the substituent is selected from a halogen atom, a cyano group, a nitro group, a trialkylsilyl group (of which the alkyl groups are independently a linear or branched alkyl group having 1 to 8 carbon atoms), a linear or branched alkyl group having 1 to 20 carbon atoms (of which the alkyl group can include one or non-neighboring two or more methylene groups that can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C— and the alkyl group can include a hydrogen atom that can be replaced with a fluorine atom)},    J is a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms (of which the alkyl group can include a hydrogen atom that can be optionally replaced with a fluorine atom), or an aromatic cyclic group capable of having a substituent {of which the substituent is selected from a halogen atom, a cyano group, a nitro group, a trialkylsilyl group (of which the alkyl groups are independently a linear or branched alkyl group having 1 to 8 carbon atoms), or a linear or branched alkyl group having 1 to 20 carbon atoms (of which the alkyl group can include one or non-neighboring two or more methylene groups that can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C— and the alkyl group can include a hydrogen atom that can be replaced with a fluorine atom)};    wherein the compound represented by the formula (1) includes at least one cyclic group having a substituent.