Carbazole Derivative, and Light-Emitting Element, Light-Emitting Device, and Electronic Device Using Carbazole Derivative

Abstract

To provide a light-emitting element having high luminous efficiency and to provide a light-emitting device and an electronic device which consumes low power and is driven at low voltage, a carbazole derivative represented by the general formula (1) is provided. In the formula, α 1 , α 2 , α 3 , and α 4 each represent an arylene group having less than or equal to 13 carbon atoms; Ar 1 and Ar 2 each represent an aryl group having less than or equal to 13 carbon atoms; R 1 represents any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, and a substituted or unsubstituted biphenyl group; and R 2 represents any of an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, and a substituted or unsubstituted biphenyl group. In addition, l, m, and n are each independently 0 or 1.

1 . A carbazole derivative represented by a general formula (1), 
     
       
         
         
             
             
         
       
       wherein α 1 , α 2 , α 3 , and α 4  each represent an arylene group having less than or equal to 13 carbon atoms, 
       wherein Ar 1  and Ar 2  each represent an aryl group having less than or equal to 13 carbon atoms, 
       wherein R 1  represents any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, and a substituted or unsubstituted biphenyl group, 
       wherein R 2  represents any of an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, and a substituted or unsubstituted biphenyl group, and 
       wherein l, m, and n are each independently 0 or 1. 
     
   
   
       2 . A carbazole derivative according to  claim 1 , wherein α 1  to α 4  in the general formula (1) are represented by any of general formulas (2-1) to (2-12), 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       wherein R 11  to R 16 , R 21  to R 30 , R 31  to R 38 , and R 41  to R 45  each represent any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, and a biphenyl group, 
       wherein R 46  and R 47  each represent any of an alkyl group having 1 to 6 carbon atoms and a phenyl group, and 
       wherein R 48  represents any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, and a biphenyl group. 
     
   
   
       3 . A carbazole derivative according to  claim 2 , wherein R 46  and R 47  are connected to each other. 
   
   
       4 . A carbazole derivative according to any one of  claims 1  to  3 , wherein Ar 1  and Ar 2  in the general formula (1) are represented by any of general formulas (3-1) to (3-6), 
     
       
         
         
             
             
         
       
       wherein R to R 56 , R 61  to R 70 , R 71  to R 81  and R 85  to R 85  each represent any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, and a biphenyl group, 
       wherein R 86  and R 87  each represent any of an alkyl group having 1 to 6 carbon atoms and a phenyl group, and 
       wherein R 88  and R 89  each represent any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, and a biphenyl group. 
     
   
   
       5 . A carbazole derivative according to  claim 4 , wherein R 86  and R 87  are connected to each other. 
   
   
       6 . A carbazole derivative according to any one of  claims 1  to  3 , wherein R 1  in the general formula (1) are represented by any of general formulas (4-1) to (4-9) and R 2  in the general formula (1) is represented by any of the general formulas (4-2) to (4-9), 
     
       
         
         
             
             
         
       
       wherein R 51  to R 70  each represent any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, and a biphenyl group. 
     
   
   
       7 . The carbazole derivative according to  claim 1 , wherein the carbazole derivative is represented by a structural formula (5). 
     
       
         
         
             
             
         
       
     
   
   
       8 . The carbazole derivative according to  claim 1 , wherein the carbazole derivative is represented by a structural formula (6). 
     
       
         
         
             
             
         
       
     
   
   
       9 . The carbazole derivative according to  claim 1 , wherein the carbazole derivative is represented by a structural formula (7). 
     
       
         
         
             
             
         
       
     
   
   
       10 . The carbazole derivative according to  claim 1 , wherein the carbazole derivative is represented by a structural formula (8). 
     
       
         
         
             
             
         
       
     
   
   
       11 . A light-emitting element comprising:
 a pair of electrodes; and   an EL layer containing a carbazole derivative,   wherein the carbazole derivative is represented by a general formula (1),   
     
       
         
         
             
             
         
       
       wherein α 1 , α 2 , α 3 , and α 4  each represent an arylene group having less than or equal to 13 carbon atoms, 
       wherein Ar 1  and Ar 2  each represent an aryl group having less than or equal to 13 carbon atoms, 
       wherein R 1  represents any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, and a substituted or unsubstituted biphenyl group, 
       wherein R 2  represents any of an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, and a substituted or unsubstituted biphenyl group, and 
       wherein l, m, and n are each independently 0 or 1. 
     
   
   
       12 . The light-emitting element according to  claim 11 ,
 wherein the EL layer at least includes a light-emitting layer and a hole-transporting layer, and   wherein the carbazole derivative is contained in the hole-transporting layer.   
   
   
       13 . The light-emitting element according to  claim 11 ,
 wherein the pair of electrodes consist of an anode and a cathode,   wherein the EL layer at least includes a light-emitting layer, a hole-transporting layer, and a hole-injecting layer,   wherein the hole-injecting layer is formed in contact with the anode, and   wherein the carbazole derivative is contained in the hole-injecting layer.   
   
   
       14 . The light-emitting element according to  claim 13 , wherein an inorganic compound which exhibits an electron-accepting property with respect to the carbazole derivative are further contained in the hole-injecting layer. 
   
   
       15 . The light-emitting element according to  claim 14 , wherein the inorganic compound is an oxide of a transition metal. 
   
   
       16 . The light-emitting element according to  claim 14  or  15 , wherein the inorganic compound is one or more kinds of titanium oxide, vanadium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, and silver oxide. 
   
   
       17 . A light-emitting device formed using the light-emitting element according to any one of  claims 11  to  15 . 
   
   
       18 . An electronic device formed using the light-emitting device according to  claim 17 .