ORGANIC ELECTROLUMINESCENT DEVICE
An organic electroluminescent device is provided and includes: a pair of electrodes; and at least one organic layer between the pair of electrodes, the at least one organic layer including a light-emitting layer. At least one of the at least one organic layers contains an iridium complex having a 5-membered heterocyclic structure consisting of a carbon atom and a nitrogen atom, and a deuterium atom on an SP2 carbon atom in the iridium complex.
1 . An organic electroluminescent device comprising:
a pair of electrodes; and
at least one organic layer between the pair of electrodes, the at least one organic layer including a light-emitting layer,
wherein at least one of the at least one organic layers contains an iridium complex having a 5-membered heterocyclic structure consisting of a carbon atom and a nitrogen atom, and a deuterium atom on an SP2 carbon atom in the iridium complex.
2 . The organic electroluminescent according to claim 1 , wherein the 5-membered heterocyclic structure is a 5-membered heterocyclic structure including two nitrogen atoms.
3 . The organic electroluminescent according to claim 1 , wherein the iridium complex is a compound represented by formula (1):
wherein R 11 to R 17 each independently represents a hydrogen atom or a substituent, at least one of R 11 to R 17 is a deuterium atom; L 11 represents a ligand and; n 11 represents an integer of from 1 to 3 and n 12 represents an integer of from 0 to 4, provided that n 11 and n 12 represent integers so that the coordination number of Ir is 6.
4 . The organic electroluminescent device according to claim 1 , wherein the iridium complex is a compound represented by formula (2):
wherein R 21 to R 27 each independently represents a hydrogen atom or a substituent, at least one of R 21 to R 24 , R 26 and R 27 is a deuterium atom; L 21 represents a ligand and; n 21 represents an integer of from 1 to 3 and n 22 represents an integer of from 0 to 4, provided that n 21 and n 22 represent integers so that the coordination number of Ir is 6.
5 . The organic electroluminescent device according to claim 1 , wherein the iridium complex is a compound represented by formula (3):
wherein R 31 to R 37 each independently represents a hydrogen atom or a substituent, at least one of R 31 to R 36 is a deuterium atom; L 31 represents a ligand and; n 31 represents an integer of from 1 to 3 and n 32 represents an integer of from 0 to 4, provided that n 31 and n 32 represent integers so that the coordination number of Ir is 6.
6 . The organic electroluminescent device according to claim 1 , wherein the light-emitting layer contains pyrrole as a host material.
7 . The organic electroluminescent device according to claim 1 , satisfying a relationship: 0≦the number of hydrogen atoms on the SP2 carbon atom/the number of deuterium atoms on the SP2 carbon atom≦1.
8 . The organic electroluminescent device according to claim 1 , wherein the light-emitting layer contains a host material having a minimum triplet excitation state, and an energy level T 1 in the minimum triplet excitation state is from 60 to 90 kcal/mol.