Organic electroluminescent element

An organic electroluminescent element comprising:

• an anode, a cathode, the anode and the cathode facing each other, and one or more light-emitting layers disposed between the anode and the cathode, wherein
• at least one light-emitting layer contains a host material represented by formula (1) and a thermally activated delayed fluorescence material represented by formula (2):
• wherein, L1 represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 36 carbon atoms, a substituted or unsubstituted carborane group, or a linked ring group formed by linking any 2 to 6 rings selected from among rings of such an aromatic hydrocarbon group, aromatic heterocyclic group, and carborane group;
• R1's each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 8 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 36 carbon atoms, a substituted or unsubstituted carborane group, or a linked ring group formed by linking 2 or 3 rings of such an aromatic hydrocarbon group, aromatic heterocyclic group, or carborane group, and at least one R1 is a substituted or unsubstituted carbazolyl group;
• and n represents an integer of 1 to 2:
• wherein, Z is a group represented by formula (2a), and in formula (2a), the ring A is an aromatic hydrocarbon ring represented by formula (2b), the ring B is a heterocycle represented by formula (2c), and the ring A and the ring B are each fused to an adjacent ring at any position;
• L2 represents an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic heterocyclic group having 3 to 18 carbon atoms, and when a+b is 2, L2 may be a single bond;
• Ar1 and Ar2 each independently represent a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms, or a linked aromatic group formed by linking 2 to 6 aromatic rings of aromatic groups selected from among the aromatic hydrocarbon group and the aromatic heterocyclic group;
• R2's independently represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms, or a linked aromatic group formed by linking 2 or 3 aromatic rings of aromatic groups selected from among the aromatic hydrocarbon group and the aromatic heterocyclic group;
• and a represents an integer of 1 to 3, b represents an integer of 0 to 3, c and d independently represent an integer of 0 to 4, and j represents an integer of 0 to 2.