Organic electroluminescent devices comprising host compounds

Abstract

The present invention relates to an organic electroluminescent device comprising a light-emitting layer B containing at least one host compound H of Formula (I) wherein each of X′ 1 and X′ 2 is independently from another selected from the group consisting of nitrogen and an optionally substituted carbon atom, and wherein at least one of R′ 1 -R′ 10 is CN and at least one of R A -R E is a substituted silane residue.

What is claimed is: 
     
         1 . An organic electroluminescent device comprising a light-emitting layer, organic electroluminescent device comprising:
 (i) 5-99% by weight of at least one host compound H comprising at least one of cyano- and silyl-substituted triphenyl-N-heteroaromatic-ring;   (ii) 0.1-10% by weight of at least one near-range charge transfer (NRCT) emitter compound E NRCT ; and   (iiia) 0.9-94.9% by weight of at least one further host compound D differing in structure from compound H; or   (iiib) 0.9-94.9% by weight of at least one thermally activated delayed fluorescence (TADF) compound E TADF  differing in structure from compound H; and   optionally   (iv) 0-94% by weight of a solvent.   
     
     
         2 . The organic electroluminescent device according to  claim 1 ,
 wherein the host compound H has a structure of the following Formula (I):   
       
         
           
           
               
               
           
         
         wherein: 
         each of X′ 1  and X′ 2  is independently from one another selected from the group consisting of N and CR Tz ; 
         R Tz  is at each occurrence independently from one another selected from the group consisting of hydrogen, deuterium, CN, CF 3 , C 1 -C 20 -alkyl, C 6 -C 18 -aryl, and C 7 -C 19 -alkaryl and, wherein C 6 -C 18 -aryl or C 7 -C 19 -alkaryl can at each occurrence be optionally substituted by a residue selected from the group consisting of C 1 -C 20 -alkyl, C 7 -C 19 -alkaryl, and C 6 -C 18 -aryl; 
         R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′w is independently from one another selected from the group consisting of hydrogen, deuterium, CN, CF 3 , C 6 -C 18 -aryl, C 7 -C 19 -alkaryl, and —SiR F R G R H , wherein C 6 -C 18 -aryl or C 7 -C 19 -alkaryl can at each occurrence be optionally substituted by a residue selected from the group consisting of C 1 -C 20 -alkyl, C 7 -C 19 -alkaryl, and C 6 -C 18 -aryl; 
         wherein at least one selected from the group consisting of R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10  is CN; 
         each of R F , R G  and R H  is selected from the group consisting of unsubstituted or substituted C 6 -C 18 -aryl, C 1 -C 20 -alkyl, C 7 -C 19 -alkaryl, C 1 -C 20 -heteroalkyl and C 3 -C 17 -heteroaryl; 
         R A , R B , R C , R D , and R E , is independently from one another selected from the group consisting of hydrogen, deuterium, CN, CF 3 , C 6 -C 18 -aryl, C 7 -C 19 -alkaryl, and —SiR K R M R N , wherein C 6 -C 18 -aryl or C 7 -C 19 -alkaryl can at each occurrence be optionally substituted by a residue selected from the group consisting of C 1 -C 20 -alkyl, C 7 -C 19 -alkaryl, and C 6 -C 18 -aryl; 
         each of R K , R M , and R N  is selected from the group consisting of unsubstituted or substituted C 6 -C 18 -aryl, C 7 -C 19 -alkaryl, C 1 -C 20 -heteroalkyl and C 3 -C 17 -heteroaryl; 
         wherein at least one selected from the group consisting of R A , R B , R C , R D  and R E  is —SiR K R M R N . 
       
     
     
         3 . The organic electroluminescent device according to  claim 2 , wherein at least one selected from the group consisting of X′ 1  and X′ 2  is N. 
     
     
         4 . The organic electroluminescent device according to  claim 2 , wherein exactly one among R A , R B , R C , R D  and R E  is —SiR K R M R N . 
     
     
         5 . The organic electroluminescent device according to  claim 2 , wherein R B  is —SiR K R M R N  and R A , R C , R D  and R E  are each hydrogen. 
     
     
         6 . The organic electroluminescent device according to  claim 2 , wherein the host compound H has a structure of the following Formula (II): 
       
         
           
           
               
               
           
         
         wherein R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10  are defined as in Formula (I). 
       
     
     
         7 . The organic electroluminescent device according to  claim 2 , wherein no more than two among R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10  are CN. 
     
     
         8 . The organic electroluminescent device according to  claim 2 , wherein exactly one among R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10  is CN and the remaining residues selected from R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10  are each hydrogen. 
     
     
         9 . The organic electroluminescent device according to  claim 2 , wherein R′ 2  is CN and R′ 1 , R′ 3 , R′ 4 , R′ 5 , R′ 6 , R′ 7 , R′ 8 , R′ 9 , and R′ 10  are each hydrogen. 
     
     
         10 . The organic electroluminescent device according to  claim 1 , wherein the NRCT emitter compound E NRCT  consists of a structure according to Formula (In): 
       
         
           
           
               
               
           
         
         wherein 
         n n  is 0 or 1; 
         m=1-n n ; 
         X 1  is N or B; 
         X 2  is N or B; 
         X 3  is N or B; 
         W is selected from the group consisting of Si(R 3 ) 2 , C(R 3 ) 2  and BR 3 ; 
         each of R 1 , R 2  and R 3  is independently from each other selected from the group consisting of:
 C 1 -C 5 -alkyl, which is optionally substituted with one or more substituents R 6 ; 
 C 6 -C 60 -aryl, which is optionally substituted with one or more substituents R 6 ; and 
 C 3 -C 57 -heteroaryl, which is optionally substituted with one or more substituents R 6 ; 
 
         each of R I , R II , R III , R IV , R V , R VI , R VII , R VIII , R IX , R X , and R XI  is independently from one another selected from the group consisting of: 
         hydrogen, 
         deuterium, 
         N(R 5 ) 2 , 
         OR 5 , 
         Si(R 5 ) 3 , 
         B(OR 5 ) 2 , 
         OSO 2 R 5 , 
         CF 3 , 
         CN, 
         halogen,
 which is optionally substituted with one or more substituents R 5  and 
 wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ; 
 
         C 1 -C 40 -alkoxy,
 which is optionally substituted with one or more substituents R 5  and 
 wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ; 
 
         C 1 -C 40 -thioalkoxy,
 which is optionally substituted with one or more substituents R 5  and 
 wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ; 
 
         C 2 -C 40 -alkenyl,
 which is optionally substituted with one or more substituents R 5  and 
 wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ; 
 
         C 2 -C 40 -alkynyl,
 which is optionally substituted with one or more substituents R 5  and 
 wherein one or more non-adjacent CH 2 -groups are each optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S or CONR 5 ; 
 
         C 6 -C 60 -aryl,
 which is optionally substituted with one or more substituents R 5 ; and 
 
         C 3 -C 57 -heteroaryl,
 which is optionally substituted with one or more substituents R 5 ; 
 
         R 5  is at each occurrence independently from one another selected from the group consisting of: hydrogen, deuterium, OPh, CF 3 , CN, F, 
         C 1 -C 5 -alkyl,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 1 -C 5 -alkoxy,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 1 -C 5 -thioalkoxy,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 2 -C 5 -alkenyl,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 2 -C 5 -alkynyl,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 6 -C 18 -aryl,
 which is optionally substituted with one or more C 1 -C 5 -alkyl substituents; 
 
         C 3 -C 17 -heteroaryl,
 which is optionally substituted with one or more C 1 -C 5 -alkyl substituents; 
 
         N(C 6 -C 18 -aryl) 2 , 
         N(C 3 -C 17 -heteroaryl) 2 ; and 
         N(C 3 -C 17 -heteroaryl)(C 6 -C 18 -aryl); 
         R 6  is at each occurrence independently from one another selected from the group consisting of hydrogen, deuterium, OPh, CF 3 , CN, F, 
         C 1 -C 5 -alkyl,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 1 -C 5 -alkoxy,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 1 -C 5 -thioalkoxy,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 2 -C 5 -alkenyl,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 2 -C 5 -alkynyl,
 wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF 3 , or F; 
 
         C 6 -C 18 -aryl,
 which is optionally substituted with one or more C 1 -C 5 -alkyl substituents; 
 
         C 3 -C 17 -heteroaryl,
 which is optionally substituted with one or more C 1 -C 5 -alkyl substituents; 
 
         N(C 6 -C 18 -aryl) 2 , 
         N(C 3 -C 17 -heteroaryl) 2 ; and 
         N(C 3 -C 17 -heteroaryl)(C 6 -C 18 -aryl); 
         wherein two or more of the substituents selected from the group consisting of R I , R II , R III , R IV , R V , R VII , R VIII , R IX , R X  and R XI  that are positioned adjacent to one another each optionally form a mono- or polycyclic, aliphatic, aromatic and/or benzo-fused ring system with the another; and 
         wherein at least one selected from the group consisting of X 1 , X 2  and X 3  is B and at least one selected from the group consisting of X 1 , X 2  and X 3  is N. 
       
     
     
         11 . The organic electroluminescent device according to  claim 10 , wherein X 1 , and X 3  each are N and X 2  is B and n n =0. 
     
     
         12 . The organic electroluminescent device according to  claim 1 , a small full width at half maximum (FWHM) of a main emission peak of the light-emitting layer is below 0.50 eV. 
     
     
         13 . The organic electroluminescent device according to  claim 1 ,
 wherein the host compound H has a lowest unoccupied molecule orbital LUMO(H) having an energy E LUMO (H) and the at least one further host compound D has a lowest unoccupied molecule orbital LUMO(D) having an energy E LUMO (D),   wherein E LUMO (H)<E LUMO (D).   
     
     
         14 . The organic electroluminescent device according to  claim 1 ,
 wherein the at least one further host compound D comprises at least one chemical moiety selected from the group consisting of carbazole, dibenzofuran, dibenzothiophene, triphenylsilane, ether oxide, and/or spirobifluorene.   
     
     
         15 . The organic electroluminescent device according to  claim 1 , wherein the TADF compound E TADF  consists of a structure according to Formula (Is): 
       
         
           
           
               
               
           
         
         wherein n is at each occurrence independently from one another 1 or 2; 
         X s  is SiPh 3 , CN or CF 3 ; 
         Ar EWG  is at each occurrence independently from one another a structure according to one of Formulas IIsa to IIsm 
       
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein # s  represents the binding site of the single bond linking Ar EWG  to the substituted central phenyl ring of Formula (1s); 
         R t  is at each occurrence independently from one another selected from the group consisting of hydrogen, deuterium, C 1 -C 5 -alkyl, wherein one or more hydrogen atoms are optionally substituted by deuterium, and C 6 -C 18 -aryl, which is optionally substituted with one or more substituents R 6s ; 
         R s  is at each occurrence independently from one another selected from the group consisting of hydrogen, deuterium, N(R 5s ) 2 , OR 5s , 
         SR 5s , Si(R 5s ) 3 , CF 3 , CN, F, 
         C 1 -C 40 -alkyl which is optionally substituted with one or more substituents R 5s  and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5s C═CR 5s , C≡C, Si(R 5s ) 2 , Ge(R 5s ) 2 , Sn(R 5s ) 2 , C═O, C═S, C═Se, C═NR 5s , P(═O)(R 5s ), SO, SO 2 , NR 5s , O, S or CONR 5s ; 
         C 1 -C 40 -thioalkoxy which is optionally substituted with one or more substituents R 5s  and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5s C═CR 5s , C≡C, Si(R 5s ) 2 , Ge(R 5s ) 2 , Sn(R 5s ) 2 , C═O, C═S, C═Se, C═NR 5s , P(═O)(R 5s ), SO, SO 2 , NR 5s , O, S or CONR 5s ; and 
         C 6 -C 60 -aryl which is optionally substituted with one or more substituents R 5s ; 
         C 3 -C 57 -heteroaryl which is optionally substituted with one or more substituents R 5s ; 
         R 5s  is at each occurrence independently from one another selected from the group consisting of hydrogen, deuterium, N(R 6s ) 2 , OR 6s , SR 6s , Si(R 6s ) 3 , CF 3 , CN, F, 
         C 1 -C 40 -alkyl which is optionally substituted with one or more substituents R 6s  and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 6s C═CR 6s , C≡C, Si(R 6s ) 2 , Ge(R 6s ) 2 , Sn(R 6s ) 2 , C═O, C═S, C═Se, C═NR 6s , P(═O)(R 6s ), SO, SO 2 , NR 6s , O, S or CONR 6s ; 
         C 6 -C 60 -aryl which is optionally substituted with one or more substituents R 6s ; and 
         C 3 -C 57 -heteroaryl which is optionally substituted with one or more substituents R 6s ; 
         R 6s  is at each occurrence independently from one another selected from the group consisting of hydrogen, deuterium, OPh, CF 3 , CN, F, 
         C 1 -C 5 -alkyl, wherein one or more hydrogen atoms are optionally, independently from each other substituted by deuterium, CN, CF 3 , or F; 
         C 1 -C 5 -alkoxy, 
         wherein one or more hydrogen atoms are optionally, independently from each other substituted by deuterium, CN, CF 3 , or F; 
         C 1 -C 5 -thioalkoxy, 
         wherein one or more hydrogen atoms are optionally, independently from each other substituted by deuterium, CN, CF 3 , or F; 
         C 6 -C 18 -aryl which is optionally substituted with one or more C 1 -C 5 -alkyl substituents; 
         C 3 -C 17 -heteroaryl which is optionally substituted with one or more C 1 -C 5 -alkyl substituents; 
         N(C 6 -C 18 -aryl) 2 ; 
         N(C 3 -C 17 -heteroaryl) 2 , and 
         N(C 3 -C 17 -heteroaryl)(C 6 -C 18 -aryl); 
         R d  is at each occurrence independently from one another selected from the group consisting of hydrogen, deuterium, N(R 5s ) 2 , OR 5s , SR 5S , Si(R 5s ) 3 , CF 3 , CN, F, 
         C 1 -C 40 -alkyl which is optionally substituted with one or more substituents R 5s  and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5s C═CR 5s , C≡C, Si(R 5s ) 2 , Ge(R 5s ) 2 , Sn(R 5s ) 2 , C═O, C═S, C═Se, C═NR 5s , P(═O)(R 5s ), SO, SO 2 , NR 5s , O, S or CONR 5s ; 
         C 1 -C 40 -thioalkoxy which is optionally substituted with one or more substituents R 5s  and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5s C═CR 5s , C≡C, Si(R 5s ) 2 , Ge(R 5s ) 2 , Sn(R 5s ) 2 , C═O, C═S, C═Se, C═NR 5s , P(═O)(R 5s ), SO, SO 2 , NR 5s , O, S or CONR 5s ; and 
         C 6 -C 60 -aryl which is optionally substituted with one or more substituents R 5s ; C 3 -C 57 -heteroaryl which is optionally substituted with one or more substituents R 5s ; 
         wherein the one or more substituents R s  or R 5s  independently from each other optionally form a mono- or polycyclic, (hetero)aliphatic, (hetero)aromatic and/or benzo-fused ring system with the one or more substituents R s  or R 5s  and 
         wherein the one or more substituents R d  independently from each other optionally form a mono- or polycyclic, (hetero)aliphatic, (hetero)aromatic and/or benzo-fused ring system with the one or more substituents R d . 
       
     
     
         16 . The organic electroluminescent device according to  claim 15 , wherein n=2 and X s  is CN. 
     
     
         17 . The organic electroluminescent device according to  claim 15 , wherein R s  is at each occurrence independently from one another selected from the group consisting of
 hydrogen, deuterium, Me,  i Pr,  t Bu, CN, CF 3 ,   Ph, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me,  i Pr,  t Bu, CN, CF 3  and Ph;   pyridinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me,  i Pr,  t Bu, CN, CF 3  and Ph;   pyrimidinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me,  i Pr,  t Bu, CN, CF 3  and Ph;   carbazolyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me,  i Pr,  t Bu, CN, CF 3  and Ph;   triazinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me,  i Pr,  t Bu, CN, CF 3  and Ph; and   N(Ph) 2 .   
     
     
         18 . An organic electroluminescent device comprising a light-emitting layer, the organic electroluminescent device comprising:
 (i) 5-99% by weight of at least one host compound H comprising at least one of cyano- and silyl-substituted triphenyl-N-heteroaromatic-ring;   (ii) 1-50% by weight of at least one emitter compound E differing in structure form compound H; and   optionally   (iii) 0-94% by weight of at least one further host compound D differing in structure from compound H; and   optionally   (iv) 0-10% by weight of at least one further emitter compound F differing in structure from compound H; and   optionally   (v) 0-94% by weight of a solvent; and   wherein the at least one emitter compound F is selected from a fluorescence emitter or a near-range charge transfer (NRCT) emitter.   
     
     
         19 . The organic electroluminescent device according to  claim 18 ,
 wherein the host compound H has a lowest unoccupied molecule orbital LUMO(H) having an energy E LUMO (H) and the at least one further host compound D has a lowest unoccupied molecule orbital LUMO(D) having an energy E LUMO (D),   wherein E LUMO (H)<E LUMO (D).   
     
     
         20 . The organic electroluminescent device according to  claim 18 ,
 wherein the at least one further host compound D comprises at least one chemical moiety selected from the group consisting of carbazole, dibenzofuran, dibenzothiophene, triphenylsilane, ether oxide, and/or spirobifluorene.