Organic electroluminescence device

Abstract

An organic electroluminescence device that includes an anode, an emitting layer that includes a host and a fluorescent dopant, an electron transporting zone, a cathode, a blocking layer adjacent to the emitting layer in the electron transporting zone where the blocking layer includes an aromatic heterocyclic derivative with an azine ring and where the triplet energy E T b (eV) of the aromatic heterocyclic derivative is larger than a triplet energy E T h (eV) of the host.

1 . An organic electroluminescence device, comprising in sequential order an anode, an emitting layer, a blocking layer, and a cathode, wherein
 the emitting layer comprises a host and a fluorescent dopant,   the blocking layer comprises an aromatic heterocyclic derivative,   a triplet energy E T   b  (eV) of the aromatic heterocyclic derivative is larger than a triplet energy E T   h  (eV) of the host,   the aromatic heterocyclic derivative is represented by formula (BL-4), formula (BL-5) or formula (BL-6);   
       
         
           
           
               
               
           
         
         wherein in formula (BL-4), D 1  to D 4  each represent a cyclic structure being fused to form a D 1  to D 4  ring, at least one of D 1  to D 4  are structured to have a hetero atom, another fused ring optionally being formed in such a manner as to cross-couple the adjacent Ds in the D 1  to D 4  ring; 
         R represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group, or residues of combination of two or more thereof; 
         when n is 1, R′ represents the same as R, 
         when n is 2 to 6, R′ represents a linking group selected from a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, and a substituted or unsubstituted heteroarylene group, and residues of combination of two or more thereof, or 
         R′ directly bonds two D 1  to D 4  rings in a single bond; 
         m is an integer of 0 to 11; 
         n is an integer of 1 to 5; and 
         when a plurality of D 1  to D 4  rings and Rs are present, the plurality of D 1  to D 4  rings and Rs are each the same or different, 
       
       
         
           
           
               
               
           
         
         wherein in the formula (BL-5), E 1  to E 4  each represent a cyclic structure being fused to form a E 1  to E 4  ring, at least one of E 1  to E 4  being structured to have a hetero atom, another fused ring optionally being formed in such a manner as to cross-couple the adjacent substituents on each of E 1  to E 4  in the E 1  to E 4  ring; 
         R represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group, or residues of combination of two or more thereof; 
         R′ represents the same as R when n is 1, 
         R′ represents a linking group selected from a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, and residues of combination of two or more thereof when n is 2 to 6, or 
         R′ directly bonds two E 1  to E 4  rings in a single bond; 
         (m+1) is an integer of 0 to 11; 
         n is an integer of 1 to 5; and 
         when a plurality of E 1  to E 4  rings and Rs are present, the plurality of E 1  to E 4  rings and Rs each are the same or different, 
       
       
         
           
           
               
               
           
         
         wherein in the formula (BL-6) F 1  to F 5  each represent a cyclic structure being fused to form a F 1  to F 5  ring, at least one of F 1  to F 5  being structured to have a hetero atom, another fused ring optionally being formed in such a manner as to cross-couple adjacent substituents on each of F 1  to F 5  in the F 1  to F 5  ring; 
         R represents a group selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group, or residues of combination of two or more thereof; 
         R′ represents the same as R when n is 1, 
         R′ represents a linking group selected from a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, and a substituted or unsubstituted heteroarylene group, and residues of combination of two or more thereof when n is 2 to 6, or 
         R′ directly bonds two F 1  to F 5  rings in a single bond; 
         m is an integer of 0 to 13; 
         n is an integer of 1 to 5; 
         when a plurality of F 1  to F 5  rings and Rs are present, the plurality of F 1  to F 5  rings and Rs each are the same or different. 
       
     
     
         2 - 14 . (canceled) 
     
     
         15 . The organic electroluminescence device of  claim 1 , wherein the aromatic heterocyclic derivative is represented by the formula (BL-4). 
     
     
         16 . The organic electroluminescence device of  claim 15 , wherein the D 1  to D 4  ring is a fused ring structure represented by a structure selected from: 
       
         
           
           
               
               
           
         
         wherein X represents CR″ or N; 
         Y represents one of O, S, NR″ and C(R″) 2 , at least one of Y in a single structure is O, S or NR″; 
         Z represents CR″ or N, at least one Z is N; and 
         one R″ is a bonding portion to R′ and the other R″s each are a hydrogen atom or independently chosen from the substituents for R. 
       
     
     
         17 . The organic electroluminescence device of  claim 1 , wherein the aromatic heterocyclic derivative is represented by the formula (BL-5). 
     
     
         18 . The organic electroluminescence device of  claim 17 , wherein the E 1  to E 4  ring is a fused ring structure represented by a structure selected from: 
       
         
           
           
               
               
           
         
         wherein X represents CR″ or N; 
         Y represents one of O, S, NR″ and C(R″) 2 , at least one Y is in a single structure being O, S or NR″; 
         Z represents CR″ or N, at least one Z representing N; and 
         one R″ is a bonding portion to R′ and the other R″s each are a hydrogen atom or independently chosen from the substituents for R. 
       
     
     
         19 . The organic electroluminescence device of  claim 1 , wherein the aromatic heterocyclic derivative is represented by the formula (BL-6). 
     
     
         20 . The organic electroluminescence device of  claim 19 , wherein the F 1  to F 5  ring is a fused ring structure represented by a structure selected from: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein X represents CR″ or N; 
         Y represents one of O, S, NR″ and C(R″) 2 , at least one Y is in a single structure being O, S or NR″; 
         Z represents CR″ or N, at least one Z representing N; and 
         one R″ is a bonding portion to R′ and the other R″s each are a hydrogen atom or independently chosen from the substituents for R. 
       
     
     
         21 . The organic electroluminescence device of  claim 1 , wherein the triplet energy E T   h  (eV) of the host is less than a triplet energy E T   d  (eV) of the dopant. 
     
     
         22 . The organic electroluminescence device of  claim 1 , wherein the triplet energy E T   b  (eV) of the aromatic heterocyclic derivative and the triplet energy E T   h  (eV) of the host satisfy E T   h +0.2<E T   b . 
     
     
         23 . The organic electroluminescence device of  claim 1 , wherein the triplet energy E T   b  (eV) of the aromatic heterocyclic derivative is greater than a triplet energy E T   alq  (eV) of tris(8-quinolinolato)aluminum complex. 
     
     
         24 . The organic electroluminescence device according to  claim 1 , wherein the dopant exhibits a fluorescent emission of a main peak wavelength of less than or equal to 550 nm. 
     
     
         25 . The organic electroluminescence device according to  claim 1 , wherein
 a hole transporting zone is positioned between the anode and the emitting layer,   a hole transporting layer is adjacent to the emitting layer in the hole transporting zone, and   wherein a triplet energy E T   ho  (eV) of the hole transporting layer is greater than the triplet energy E T   h  (eV) of the host.   
     
     
         26 . The organic electroluminescence device according to  claim 1 , wherein
 an electron injecting layer is positioned between the blocking layer and the cathode,   the electron injecting layer is made of the same material as a material of the blocking layer, and   a donor is doped in the electron injecting layer.   
     
     
         27 . The organic electroluminescence device according to  claim 1 , wherein the dopant is an aminopyrene derivative. 
     
     
         28 . The organic electroluminescence device according to  claim 1 , wherein
 an electron injecting layer is positioned between the blocking layer and the cathode, and   the electron injecting layer is made of a material different from a material of the blocking layer.   
     
     
         29 . The organic electroluminescence device according to  claim 15 , wherein an electron injecting layer is positioned between the blocking layer and the cathode, and
 an affinity Ab (eV) of the blocking layer and an affinity Ae (eV) of the electron injecting layer satisfy a relationship of Ae−Ab<0.2.   
     
     
         30 . The organic electroluminescence device according to  claim 17 , wherein
 an electron injecting layer is positioned between the blocking layer and the cathode, and   an affinity Ab (eV) of the blocking layer and an affinity Ae (eV) of the electron injecting layer satisfy a relationship of Ae−Ab<0.2.   
     
     
         31 . The organic electroluminescence device according to  claim 19 , wherein
 an electron injecting layer is positioned between the blocking layer and the cathode, and   an affinity Ab (eV) of the blocking layer and an affinity Ae (eV) of the electron injecting layer satisfy a relationship of Ae−Ab<0.2.   
     
     
         32 . The organic electroluminescence device according to  claim 1 , wherein n is 1. 
     
     
         33 . The organic electroluminescence device according to  claim 1 , wherein at least one R represents a group selected from a substituted or unsubstituted aryl group, a substituted or unsubstituted pyrimidine group and a substituted or unsubstituted triazine group, or residues of combination of two or more thereof. 
     
     
         34 . The organic electroluminescence device according to  claim 15 , wherein n in the formula (BL-4) is 1. 
     
     
         35 . The organic electroluminescence device according to  claim 15 , wherein n in the formula (BL-4) is 1, and
 at least one R in the formula (BL-4) represents a group selected from a substituted or unsubstituted aryl group, a substituted or unsubstituted pyrimidine group and a substituted or unsubstituted triazine group, or residues of combination of two or more thereof.   
     
     
         36 . The organic electroluminescence device according to  claim 17 , wherein n in the formula (BL-5) is 1. 
     
     
         37 . The organic electroluminescence device according to  claim 17 , wherein n in the formula (BL-5) is 1, and
 at least one R in the formula (BL-5) represents a group selected from a substituted or unsubstituted aryl group, a substituted or unsubstituted pyrimidine group and a substituted or unsubstituted triazine group, or residues of combination of two or more thereof.   
     
     
         38 . The organic electroluminescence device according to  claim 19 , wherein n in the formula (BL-6) is 1. 
     
     
         39 . The organic electroluminescence device according to  claim 19 , wherein n in the formula (BL-6) is 1, and
 at least one R in the formula (BL-6) represents a group selected from a substituted or unsubstituted aryl group, substituted or unsubstituted pyrimidine group and a substituted or unsubstituted triazine group, or residues of combination of two or more thereof.