Light-Emitting Device, Light-Emitting Apparatus, Electronic Device, and Lighting Device

Abstract

A light-emitting device with low driving voltage and favorable reliability is provided. The light-emitting device includes an electron-injection layer between a cathode and a light-emitting layer. The electron-injection layer is a mixed film of a metal and an organic compound having a function of interacting with the metal as a tridentate or tetradentate ligand, and the metal atom and the organic compound form SOMO.

1 . A compound represented by Formula (G1): 
       
         
           
           
               
               
           
         
         wherein each of X 1  and X 2  represents a nitrogen atom, 
         wherein one of X 3  and X 4  represents a nitrogen atom, 
         wherein the other of X 3  and X 4  represents:
 a nitrogen atom, or 
 a carbon atom bonding to any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms, and a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms, 
 
         wherein one of X 5  and X 6  represents a nitrogen atom, 
         wherein the other of X 5  and X 6  represents:
 a nitrogen atom, or 
 a carbon atom bonding to any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms, and a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms, 
 
         wherein each of R 1  to R 4  independently represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms, and a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms, 
         wherein Ar represents one of a pyrimidine group, a pyrazine group and a pyridazine group, 
         wherein the one of a pyrimidine group, a pyrazine group and a pyridazine group is substituted with an aryl group, and 
         wherein the triazine ring including X 1  and X 2  bonds to the one of a pyrimidine group, a pyrazine group and a pyridazine group. 
       
     
     
         2 . The compound according to  claim 1 , wherein each of X 3  and X 6  represents a nitrogen atom. 
     
     
         3 . The compound according to  claim 1 ,
 wherein each of X 3  and X 6  represents a nitrogen atom, and   wherein each of X 4  and X 6  represents a carbon atom bonding to hydrogen or a phenyl group.   
     
     
         4 . The compound according to  claim 1 ,
 wherein the other of X 3  and X 4  represents a carbon atom bonding to hydrogen or a phenyl group, and   wherein the other of X 5  and X 6  represents a carbon atom bonding to hydrogen or a phenyl group.   
     
     
         5 . The compound according to  claim 1 , wherein Ar represents a pyrimidine group substituted by the aryl group. 
     
     
         6 . The compound according to  claim 1 , wherein the one of a pyrimidine group, a pyrazine group and a pyridazine group is substituted by a phenyl group. 
     
     
         7 . The compound according to  claim 1 ,
 wherein each of the carbon atom in the other of X 3  and X 4  is substituted by a phenyl group, and   wherein each of the carbon atom in the other of X 5  and X 6  is substituted by a phenyl group.   
     
     
         8 . The compound according to  claim 1 , wherein Formula (G1) is Formula (105): 
       
         
           
           
               
               
           
         
       
     
     
         9 . A light-emitting device comprising:
 the compound according to  claim 1 .   
     
     
         10 . A light-emitting device comprising:
 a first electrode;   a light-emitting layer over the first electrode;   an electron-injection layer over the light-emitting layer, the electron-injection layer comprising:
 the compound according to  claim 1 ; and 
 a metal belonging to any of Group 3 to Group 13 of a periodic table; and 
   a second electrode.   
     
     
         11 . The light-emitting device according to  claim 10 , wherein the metal is Ag or Cu. 
     
     
         12 . An electronic device comprising:
 the light-emitting device according to  claim 9 .   
     
     
         13 . A lighting device comprising:
 the light-emitting device according to  claim 9 .