Light-emitting material comprising orthometalated iridium complex, light-emitting device, high efficiency red light-emitting device, and novel iridium complex

Abstract

A light-emitting material comprises a compound having a partial structure represented by the following formulas (8), (20) and tautomers thereof: wherein the variables are as defined in the specification.

1 . An organic light-emitting device comprising a light-emitting layer or a plurality of organic compound layers containing a light-emitting layer between a pair of electrodes, wherein at least one layer comprises at least one material having a partial structure selected from the following formula (20) and a tautomer thereof:  
     
       
         
         
             
             
         
       
     
     wherein Z 201  represents an atomic group for forming an aryl ring, Z 401  represents an atomic group for forming an aryl or heteroaryl ring, L 203  is a nitrogen-containing heterocyclic ligand to coordinate Ir metal as bidentate ligand, m203 represents 3 and n203 represents 0, and m203 and n203 represents the number of ligands required to satisfy coordination number 6 of iridium.  
   
   
       2 . The organic light-emitting device according to  claim 1 , wherein Z 401  represents an atomic group for forming an aryl ring.  
   
   
       3 . The organic light-emitting device according to  claim 2 , wherein Z 401  is a phenyl group.  
   
   
       4 . The organic light-emitting device according to  claim 1 , wherein Z 201  is a phenyl group, naphthyl group, anthryl group, phenanthryl group or pyrenyl group.  
   
   
       5 . The organic light-emitting device according to  claim 4 , wherein Z 401  is a phenyl group.