Organic electroluminescent device

1 . An organic electroluminescent device comprising a light-emitting layer B comprising:

(i) a first compound H N , which has a lowermost excited singlet state energy level S1 N , a lowermost excited triplet state energy level T1 N ,

(ii) a second compound E B , which has a lowermost excited singlet state energy level S1 E and a lowermost excited triplet state energy level T1 E , and

(iii) a third compound S B , which has a lowermost excited singlet state energy level S1 S and a lowermost excited triplet state energy level T1 S

wherein the relations expressed by the following formulas (1) to (3) apply:

S 1 E >S 1 S   (1)

S 1 N >S 1 S   (2)

S 1 S <2.95 eV  (3),

wherein the second compound E B comprises a structure according to Formula I-TADF:

wherein

n is 1 or 2;

X is selected from the group of Ar EWG , CN or CF 3 ;

Z is selected from the group of a direct bond, CR 3 R 4 , C═CR 3 R 4 , C═O, C═NR 3 , NR 3 , O, SiR 3 R 4 , S, S(O) and S(O) 2 ;

Ar EWG is selected from one of Formulas IIa to IIk;

wherein # represents the binding site of the single bond linking Ar EWG to the substituted central phenyl ring of Formula I-TADF;

each of R 1 and R 2 is independently from 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 6 ;

each of R a , R 3 and R 4 is independently from another selected from the group consisting of:

hydrogen, deuterium, N(R 5 ) 2 , OR 5 , SR 5 , Si(R 5 ) 3 , CF 3 , CN, F,

C 1 -C 40 -alkyl,

which is optionally substituted with one or more substituents R 5 and wherein one or more non-adjacent CH 2 -groups are 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 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 ; and

C 6 -C 60 -aryl,

which is optionally substituted with one or more substituents R 5 ; C 3 -C 57 -heteroaryl which is optionally substituted with one or more substituents R 5 ;

R 5 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R 6 ) 2 , OR 6 , SR 6 , Si(R 6 ) 3 , CF 3 , CN, F,

C 1 -C 40 -alkyl,

which is optionally substituted with one or more substituents R 6 and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 6 C═CR 6 , C≡C, Si(R 6 ) 2 , Ge(R 6 ) 2 , Sn(R 6 ) 2 , C═O, C═S, C═Se, C═NR 6 , P(═O)(R 6 ), SO, SO 2 , NR 6 , O, S or CONR 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 ;

R 6 is at each occurrence independently from 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 12 -heteroaryl)(C 6 -C 18 -aryl);

R d is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R 5 ) 2 , OR S , SR S , Si(R 5 ) 3 , CF 3 , CN, F,

C 1 -C 40 -alkyl,

which is optionally substituted with one or more substituents R 5 and wherein one or more non-adjacent CH 2 -groups are 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 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 ; and

C 6 -C 60 -aryl,

which is optionally substituted with one or more substituents R 5 ; C 3 -C 57 -heteroaryl which is optionally substituted with one or more substituents R 5 ;

wherein the substituents R a , R 3 , R 4 or R 5 independently from each other optionally may form a mono- or polycyclic, aliphatic, aromatic and/or benzo-fused ring system with one or more substituents R a , R 3 , R 4 or R 5 and

wherein the one or more substituents R d independently from each other optionally may form a mono- or polycyclic, aliphatic, aromatic and/or benzo-fused ring system with one or more substituents R d .

2 . The organic electroluminescent device according to claim 1 , wherein the second compound E B exhibits a ΔE ST value, which corresponds to the energy difference between the lowermost excited singlet state (S1) and the lowermost excited triplet state (T1), of less than 0.4 eV; and wherein the third compound S B exhibits an emission with a full width at half maximum (FWHM) below 0.35 eV, in PMMA with 5% by weight of the third compound S B .

3 . The organic electroluminescent device according to claim 1 , wherein said organic electroluminescent device is a device selected from the group consisting of an organic light emitting diode, a light emitting electrochemical cell, and a light-emitting transistor.

4 . The organic electroluminescent device according to claim 1 , wherein the second compound E B is an organic TADF material.

5 . The organic electroluminescent device according to claim 1 , wherein the device exhibits an emission maximum λ max (D) of 440 to 475 nm.

6 . The organic electroluminescent device according to claim 1 , wherein the light-emitting layer B comprises:

(i) 10-96.5% by weight of the first compound H N ;

(ii) 3-50% by weight of the second compound E B ; and

(iii) 0.5-30% by weight of the third compound S B ; and

(iv) optionally 0-74% by weight of one or more solvents.

7 . The organic electroluminescent device according to claim 1 , wherein the light-emitting layer B comprises:

(i) 40-74% by weight of the first compound H N ;

(ii) 15-30% by weight of the second compound E B ; and

(iii) 1-5% by weight of the third compound S B ; and

(iv) optionally 0-34% by weight of one or more solvents.

8 . An organic electroluminescent device comprising a light-emitting layer B comprising:

(i) a first compound H N , which has a lowermost excited singlet state energy level S1 N , a lowermost excited triplet state energy level T1 N ,

(ii) a second compound E B , which has a lowermost excited singlet state energy level S1 E and a lowermost excited triplet state energy level T1 E , and

(iii) a third compound S B , which has a lowermost excited singlet state energy level S1 S and a lowermost excited triplet state energy level T1 S

wherein the relations expressed by the following formulas (1) to (3) apply:

S 1 E >S 1 S   (1)

S 1 N >S 1 S   (2)

S 1 S <2.95 eV  (3),

wherein the first compound H N is an anthracene derivative.

9 . The organic electroluminescent device according to claim 1 , wherein the third compound S B comprises a structure according to Formula I-NRCT:

wherein

o is 0 or 1;

m=1-o;

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 3S ) 2 , C(R 3S ) 2 and BR 3S ;

each of R 1S , R 2S and R 3S is independently selected from the group consisting of:

C 1 -C 5 -alkyl,

which is optionally substituted with one or more substituents R 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 6 S;

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 selected from the group consisting of:

hydrogen, deuterium, N(R 5S ) 2 , OR 5S , Si(R 5S ) 3 , B(OR 5S ) 2 , OSO 2 R 5S , CF 3 , CN, halogen,

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 each 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 -alkoxy,

which is optionally substituted with one or more substituents R 5S and

wherein one or more non-adjacent CH 2 -groups are each 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 each 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 2 -C 40 -alkenyl,

which is optionally substituted with one or more substituents R 5S and

wherein one or more non-adjacent CH 2 -groups are each 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 2 -C 40 -alkynyl,

which is optionally substituted with one or more substituents R 5S and

wherein one or more non-adjacent CH 2 -groups are each 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 6 -C 60 -aryl,

which is optionally substituted with one or more substituents R 5S ; and

C 3 -C 57 -heteroaryl,

which is optionally substituted with one or more substituents R 5S ;

R 5S is at each occurrence independently from 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 6S is at each occurrence independently from 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 VI , R VII , R VIII , R IX , R X , and R XI that are positioned adjacent to another may optionally each form a ring system with another, wherein the ring system is selected from the group consisting of mono- or polycyclic ring system, aliphatic ring system, aromatic ring system, benzo-fused ring system and combinations thereof; and

wherein at least one of X 1 , X 2 and X 3 is B and at least one of X 1 , X 2 and X 3 is N.

10 . The organic electroluminescent device according to claim 9 , wherein X 1 and X 3 each are N and X 2 is B.

11 . The organic electroluminescent device according to claim 9 , wherein X 1 and X 3 each are B and X 2 is N.

12 . The organic electroluminescent device according to claim 9 , wherein o=0.

13 . The organic electroluminescent device according to claim 9 , wherein 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 selected from the group consisting of:

hydrogen, deuterium, halogen, Me, i Pr, t Bu, CN, CF 3 ,

Ph, which is optionally substituted with one or more substituents independently 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 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 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 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 selected from the group consisting of Me, i Pr, t Bu, CN, CF 3 , and Ph,

and N(Ph) 2 ; and

R 1S and R 2S are each independently selected from the group consisting of C 1 -C 5 -alkyl,

which is optionally substituted with one or more substituents R 6S ;

C 6 -C 30 -aryl,

which is optionally substituted with one or more substituents R 6S ; and

C 3 -C 30 -heteroaryl,

which is optionally substituted with one or more substituents R 6S .

14 . The organic electroluminescent device according to claim 1 , wherein the device exhibits an emission maximum λ max (D) of 450 to 470 nm.

15 . The organic electroluminescent device according to claim 1 , wherein the device exhibits a CIEx color coordinate of between 0.02 and 0.30 and/or a CIEy color coordinate of between 0.00 and 0.45.

16 . The organic electroluminescent device according to claim 1 , wherein the third compound S B is an organic material.

17 . The organic electroluminescent device according to claim 8 , wherein the device exhibits a CIEx color coordinate of between 0.02 and 0.30 and/or a CIEy color coordinate of between 0.00 and 0.45.

18 . An organic electroluminescent device comprising a light-emitting layer B comprising:

(i) a first compound H N , which has a lowermost excited singlet state energy level S1 N , a lowermost excited triplet state energy level T1 N ,

(ii) a second compound E B , which has a lowermost excited singlet state energy level S1 E and a lowermost excited triplet state energy level T1 E , and

(iii) a third compound S B , which has a lowermost excited singlet state energy level S1 S and a lowermost excited triplet state energy level T1 S

wherein the relations expressed by the following formulas (1) to (3) apply:

S 1 E >S 1 S   (1)

S 1 N >S 1 S   (2)

S 1 S <2.95 eV  (3),

wherein the second compound E B is a carbazole derivative.

19 . The organic electroluminescent device according to claim 18 , wherein the device exhibits a CIEx color coordinate of between 0.02 and 0.30 and/or a CIEy color coordinate of between 0.00 and 0.45.