Organic electroluminescent device emitting blue light

Abstract

The present invention relates to organic electroluminescent devices comprising a light-emitting layer B comprising a host material H.sup.B, a first thermally activated delayed fluorescence (TADF) material E.sup.B, and a depopulation agent S.sup.B.

Claims

1. An organic electroluminescent device comprising a light-emitting layer B comprising: (i) a host material H.sup.B, which has a lowest unoccupied molecular orbital LUMO(H.sup.B) having an energy E.sup.LUMO(H.sup.B) and a highest occupied molecular orbital HOMO(H.sup.B) having an energy E.sup.HOMO(H.sup.B); (ii) a thermally activated delayed fluorescence (TADF) material E.sup.B, which has a lowermost excited singlet state energy level S1.sup.E, a lowermost excited triplet state energy level T1.sup.E, a lowest unoccupied molecular orbital LUMO(E.sup.B) having an energy E.sup.LUMO(E.sup.B) and a highest occupied molecular orbital HOMO(E.sup.B) having an energy E.sup.HOMO(E.sup.B); and (iii) an depopulation agent S.sup.B, which has a lowermost excited singlet state energy level S1.sup.S, a lowermost excited triplet state energy level T1.sup.S, a lowest unoccupied molecular orbital LUMO(S.sup.B) having an energy E.sup.LUMO(S.sup.B) and a highest occupied molecular orbital HOMO(S.sup.B) having an energy E.sup.HOMO(S.sup.B), wherein E.sup.B emits thermally activated delayed fluorescence; and wherein the relations expressed by the following formulas (1) to (2) and either (3a) and (3b) or (4a) and (4b) apply:
S1.sup.S≥S1.sup.E  (1)
T1.sup.S≥2.5 eV  (2)
E.sup.LUMO(E.sup.B)<E.sup.LUMO(H.sup.B)  (3a)
0.2 eV<E.sup.LUMO(E.sup.B)−E.sup.LUMO(S.sup.B)<0.5 eV  (3b)
E.sup.LUMO(E.sup.B)>E.sup.LUMO(H.sup.B)  (4a)
0.2 eV<E.sup.LUMO(H.sup.B)−E.sup.LUMO(S.sup.B)<0.5 eV  (4b), and wherein the mass ratio of TADF material to depopulation agent (E.sup.B:S.sup.B) is >1.

2. The organic electroluminescent device according to claim 1, the TADF material E.sup.B is characterized in that it has a ΔE.sub.ST value, which corresponds to the energy difference between S1.sup.E and T1.sup.E, of less than 0.4 eV.

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 TADF material E.sup.B is an organic TADF emitter or a combination of two or more organic TADF emitters.

5. The organic electroluminescent device according to claim 1, wherein the depopulation agent S.sup.B is an organic TADF emitter or a combination of two or more organic TADF emitters.

6. The organic electroluminescent device according to claim 1, wherein the relation expressed by the following formula (5a) or (5b) applies:
E.sup.HOMO(E.sup.B)>E.sup.HOMO(H.sup.B)  (5a)
E.sup.HOMO(E.sup.B)<E.sup.HOMO(H.sup.B)  (5b).

7. The organic electroluminescent device according to claim 1, wherein the relation expressed by the following formula (6) applies:
E.sup.HOMO(S.sup.B)<E.sup.HOMO(H.sup.B)  (6).

8. The organic electroluminescent device according to claim 1, wherein the device exhibits an emission maximum λ.sub.max(D) of 440 to 480 nm.

9. The organic electroluminescent device according to claim 1, wherein the light-emitting layer B comprises: (i) 40-98% by weight of the host material H.sup.B; (ii) 1-50% by weight of the TADF material E.sup.B; and (iii) 1-10% by weight of the depopulation agent S.sup.B; and optionally (iv) 0-58% by weight of one or more further host materials H.sup.B2 differing from H.sup.B; and optionally (v) 0-58% by weight of one or more solvents.

10. The organic electroluminescent device according to claim 1, wherein the light-emitting layer B comprises the depopulation agent S.sup.B in 2-8% by weight.

11. The organic electroluminescent device according to claim 1, wherein the TADF material E.sup.B comprises a first chemical moiety comprising a structure of Formula I, ##STR00068## and one or two second chemical moieties comprising a structure of Formula II, ##STR00069## wherein the first chemical moiety is linked to each of the second chemical moiety via a single bond; Q.sup.I is either N or CH; Q.sup.II is either N or CH; T is selected from the group consisting of the binding site of a single bond linking the first chemical moiety to the second chemical moiety, hydrogen (H), deuterium (D), and R.sup.1; V is selected from the group consisting of the binding site of a single bond linking the first chemical moiety to the second chemical moiety, H, D, and R.sup.1; W is selected from the group consisting of the binding site of a single bond linking the first chemical moiety to the second chemical moiety, H, D, and R.sup.1; X is selected from the group consisting of the binding site of a single bond linking the first chemical moiety to the second chemical moiety, H, D, and R.sup.1; Y is selected from the group consisting of the binding site of a single bond linking the first chemical moiety to the second chemical moiety, H, D, and R.sup.1; # represents the binding site of a single bond linking the one or two second chemical moieties to the first chemical moiety; Z is at each occurrence independently from another selected from the group consisting of a direct bond, CR.sup.3R.sup.4, C═CR.sup.3R.sup.4, C═O, C═NR.sup.3, NR.sup.3, O, SiR.sup.3R.sup.4, S, S(O), and S(O).sub.2; R.sup.1 is selected from the group consisting of CN, CF.sub.3, SiPh.sub.3, GePh.sub.3, and a third chemical moiety comprising a structure of Formula Q: ##STR00070## wherein Q.sup.1 is selected from the group consisting of N and C—R.sup.I; Q.sup.2 is selected from the group consisting of N and C—R.sup.II; Q.sup.3 is selected from the group consisting of N and C—R.sup.III; Q.sup.5 is selected from the group consisting of N and C—R.sup.V; and $ represents the binding site of a single bond linking the third chemical moiety to the first chemical moiety; R.sup.I is selected from the group consisting of H, D, CN, CF.sub.3, SiPh.sub.3, GePh.sub.3, F, phenyl, which is optionally substituted with one or more substituents R.sup.6; triazinyl, which is optionally substituted with one or more substituents R.sup.6; pyridyl, which is optionally substituted with one or more substituents R.sup.6; pyrimidyl, which is optionally substituted with one or more substituents R.sup.6; and a fourth chemical moiety comprising or consisting of a structure of Formula IIQ: ##STR00071## § represents the binding site of a single bond linking the fourth chemical moiety to the third chemical moiety; Z.sup.§ is at each occurrence independently from another selected from the group consisting of a direct bond, CR.sup.3R.sup.4, C═CR.sup.3R.sup.4, C═O, C═NR.sup.3, NR.sup.3, O, SiR.sup.3R.sup.4, S, S(O), and S(O).sub.2; R.sup.II is at each occurrence independently from another selected from the group consisting of H, D, CN, CF.sub.3, SiPh.sub.3, GePh.sub.3, F, phenyl, which is optionally substituted with one or more substituents R.sup.6; triazinyl, which is optionally substituted with one or more substituents R.sup.6; pyridyl, which is optionally substituted with one or more substituents R.sup.6; pyrimidyl, which is optionally substituted with one or more substituents R.sup.6; and a fourth chemical moiety comprising or consisting of a structure of Formula IIQ; R.sup.III is at each occurrence independently from another selected from the group consisting of H, D, CN, CF.sub.3, SiPh.sub.3, GePh.sub.3, F, triazinyl, which is optionally substituted with one or more substituents R.sup.6; pyridyl, which is optionally substituted with one or more substituents R.sup.6; pyrimidyl, which is optionally substituted with one or more substituents R.sup.6; and a fourth chemical moiety comprising or consisting of a structure of Formula IIQ; R.sup.IV is at each occurrence independently from another selected from the group consisting of H, D, CN, CF.sub.3, SiPh.sub.3, GePh.sub.3, F, phenyl, which is optionally substituted with one or more substituents R.sup.6; triazinyl, which is optionally substituted with one or more substituents R.sup.6; pyridyl, which is optionally substituted with one or more substituents R.sup.6; pyrimidyl, which is optionally substituted with one or more substituents R.sup.6; R.sup.V is at each occurrence independently from another selected from the group consisting of H, D, CN, CF.sub.3, SiPh.sub.3, GePh.sub.3, F, triazinyl, which is optionally substituted with one or more substituents R.sup.6; pyridyl, which is optionally substituted with one or more substituents R.sup.6; pyrimidyl, which is optionally substituted with one or more substituents R.sup.6; R.sup.a, R.sup.3, and R.sup.4 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R.sup.5).sub.2, OR.sup.5, Si(R.sup.5).sub.3, B(OR.sup.5).sub.2, OSO.sub.2R.sup.5, CF.sub.3, CN, F, Br, I, C.sub.1-C.sub.40-alkyl, which is optionally substituted with one or more substituents R.sup.5 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5C═CR.sup.5, C≡C, Si(R.sup.5).sub.2, Ge(R.sup.5).sub.2, Sn(R.sup.5).sub.2, C═O, C═S, C═Se, C═NR.sup.5, P(═O)(R.sup.5), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5; C.sub.1-C.sub.40-alkoxy, which is optionally substituted with one or more substituents R.sup.5 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5C═CR.sup.5, C≡C, Si(R.sup.5).sub.2, Ge(R.sup.5).sub.2, Sn(R.sup.5).sub.2, C═O, C═S, C═Se, C═NR.sup.5, P(═O)(R.sup.5), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5; C.sub.1-C.sub.40-thioalkoxy, which is optionally substituted with one or more substituents R.sup.5 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5C═CR.sup.5, C≡C, Si(R.sup.5).sub.2, Ge(R.sup.5).sub.2, Sn(R.sup.5).sub.2, C═O, C═S, C═Se, C═NR.sup.5, P(═O)(R.sup.5), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5; C.sub.2-C.sub.40-alkenyl, which is optionally substituted with one or more substituents R.sup.5 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5C═CR.sup.5, C≡C, Si(R.sup.5).sub.2, Ge(R.sup.5).sub.2, Sn(R.sup.5).sub.2, C═O, C═S, C═Se, C═NR.sup.5, P(═O)(R.sup.5), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5; C.sub.2-C.sub.40-alkynyl, which is optionally substituted with one or more substituents R.sup.5 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5C═CR.sup.5, C≡C, Si(R.sup.5).sub.2, Ge(R.sup.5).sub.2, Sn(R.sup.5).sub.2, C═O, C═S, C═Se, C═NR.sup.5, P(═O)(R.sup.5), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5; C.sub.6-C.sub.60-aryl, which is optionally substituted with one or more substituents R.sup.5; and C.sub.3-C.sub.57-heteroaryl, which is optionally substituted with one or more substituents R.sup.5; R.sup.5 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R.sup.6).sub.2, OR.sup.6, Si(R.sup.6).sub.3, B(OR.sup.6).sub.2, OSO.sub.2R.sup.6; CF.sub.3, CN, F, Br, I, C.sub.1-C.sub.40-alkyl, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.1-C.sub.40-alkoxy, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.1-C.sub.40-thioalkoxy, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.2-C.sub.40-alkenyl, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.2-C.sub.40-alkynyl, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.6-C.sub.60-aryl, which is optionally substituted with one or more substituents R.sup.6; and C.sub.3-C.sub.57-heteroaryl, which is optionally substituted with one or more substituents R.sup.6; R.sup.f is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R.sup.5f).sub.2, OR.sup.5f, Si(R.sup.5f).sub.3, B(OR.sup.5f).sub.2, OSO.sub.2R.sup.5f, CF.sub.3, CN, F, Br, I, C.sub.1-C.sub.40-alkyl, which is optionally substituted with one or more substituents R.sup.5f and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5fC═CR.sup.5f, C≡C, Si(R.sup.5f).sub.2, Ge(R.sup.5f).sub.2, Sn(R.sup.5f).sub.2, C═O, C═S, C═Se, C═NR.sup.5f, P(═O)(R.sup.5f), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5f; C.sub.1-C.sub.40-alkoxy, which is optionally substituted with one or more substituents R.sup.5f and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5fC═CR.sup.5f, C≡C, Si(R.sup.5f).sub.2, Ge(R.sup.5f).sub.2, Sn(R.sup.5f).sub.2, C═O, C═S, C═Se, C═NR.sup.5f, P(═O)(R.sup.5f), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5f; C.sub.1-C.sub.40-thioalkoxy, which is optionally substituted with one or more substituents R.sup.5f and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5fC═CR.sup.5f, C≡C, Si(R.sup.5f).sub.2, Ge(R.sup.5f).sub.2, Sn(R.sup.5f).sub.2, C═O, C═S, C═Se, C═NR.sup.5f, P(═O)(R.sup.5f), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5f; C.sub.2-C.sub.40-alkenyl, which is optionally substituted with one or more substituents R.sup.5f and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5fC═CR.sup.5f, C≡C, Si(R.sup.5f).sub.2, Ge(R.sup.5f).sub.2, Sn(R.sup.5f).sub.2, C═O, C═S, C═Se, C═NR.sup.5f, P(═O)(R.sup.5f), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5f; C.sub.2-C.sub.40-alkynyl, which is optionally substituted with one or more substituents R.sup.5f and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5fC═CR.sup.5f, C≡C, Si(R.sup.5f).sub.2, Ge(R.sup.5f).sub.2, Sn(R.sup.5f).sub.2, C═O, C═S, C═Se, C═NR.sup.5f, P(═O)(R.sup.5f), SO, SO.sub.2, NR.sup.5, O, S, or CONR.sup.5f; C.sub.6-C.sub.60-aryl, which is optionally substituted with one or more substituents R.sup.5f; and C.sub.3-C.sub.57-heteroaryl, which is optionally substituted with one or more substituents R.sup.5f; R.sup.5f is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R.sup.6).sub.2, OR.sup.6, Si(R.sup.6).sub.3, B(OR.sup.6).sub.2, OSO.sub.2R.sup.6, CF.sub.3, CN, F, Br, I, C.sub.1-C.sub.40-alkyl, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.1-C.sub.40-alkoxy, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.1-C.sub.40-thioalkoxy, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.2-C.sub.40-alkenyl, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.2-C.sub.40-alkynyl, which is optionally substituted with one or more substituents R.sup.6 and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6C═CR.sup.6, C≡C, Si(R.sup.6).sub.2, Ge(R.sup.6).sub.2, Sn(R.sup.6).sub.2, C═O, C═S, C═Se, C═NR.sup.6, P(═O)(R.sup.6), SO, SO.sub.2, NR.sup.6, O, S, or CONR.sup.6; C.sub.6-C.sub.60-aryl, which is optionally substituted with one or more substituents R.sup.6; and C.sub.3-C.sub.57-heteroaryl, which is optionally substituted with one or more substituents R.sup.6; R.sup.6 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, OPh, CF.sub.3, CN, F, C.sub.1-C.sub.5-alkyl, wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF.sub.3, or F; C.sub.1-C.sub.5-alkoxy, wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF.sub.3, or F; C.sub.1-C.sub.5-thioalkoxy, wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF.sub.3, or F; C.sub.2-C.sub.5-alkenyl, wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF.sub.3, or F; C.sub.2-C.sub.5-alkynyl, wherein optionally one or more hydrogen atoms are independently from each other substituted by deuterium, CN, CF.sub.3, or F; C.sub.6-C.sub.18-aryl, which is optionally substituted with one or more C.sub.1-C.sub.5-alkyl substituents; C.sub.3-C.sub.17-heteroaryl, which is optionally substituted with one or more C.sub.1-C.sub.5-alkyl substituents; N(C.sub.6-C.sub.18-aryl).sub.2; N(C.sub.3-C.sub.17-heteroaryl).sub.2; and N(C.sub.3-C.sub.17-heteroaryl)(C.sub.6-C.sub.18-aryl); R.sup.Tz is at each occurrence independently from another selected from the group consisting of CN, CF.sub.3, SiPh.sub.3, F, phenyl, which is optionally substituted with one or more substituents R.sup.6; triazinyl, which is optionally substituted with one or more substituents R.sup.6; pyridyl, which is optionally substituted with one or more substituents R.sup.6; pyrimidyl, which is optionally substituted with one or more substituents R.sup.6; wherein the substituents R.sup.a, R.sup.3, R.sup.4, or R.sup.5 independently from each other optionally form a mono- or polycyclic, (hetero)aliphatic, (hetero)aromatic, benzo-fused ring system, or a combination thereof with one or more substituents R.sup.a, R.sup.3, R.sup.4, or R.sup.5; wherein the substituents R.sup.f or R.sup.5f independently from each other optionally form a mono- or polycyclic, (hetero)aliphatic, (hetero)aromatic, benzo-fused ring system, or a combination thereof with one or more substituents R.sup.f or R.sup.5f; wherein at least one of Q.sup.I and Q.sup.II is N; wherein one or two substituents selected from the group consisting of T, V, W, X, and Y represent the binding site of a single bond linking the first chemical moiety and the second chemical moiety; wherein exactly one substituent selected from the group consisting of T, V, W, X, and Y is R.sup.1.

12. The organic electroluminescent device according to claim 11, wherein the TADF material E.sup.B consists of a structure of Formula Ia: ##STR00072## wherein R.sup.1, Q.sup.I, and Q.sup.II are defined as in claim 11; T.sup.# is selected from the group consisting of the binding site of a single bond linking the first chemical moiety to the second chemical moiety, H, D, and R.sup.1; W.sup.# is selected from the group consisting of the binding site of a single bond linking the first chemical moiety to the second chemical moiety, H, D, and R.sup.1; wherein exactly one substituent selected from the group consisting of T.sup.# and W.sup.# represents the binding site of a single bond linking the first chemical moiety and the second chemical moiety.

13. The organic electroluminescent device according to claim 11, wherein Z is a direct bond at each occurrence.

14. The organic electroluminescent device according to claim 11, wherein R.sup.a is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, Ph, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; pyridinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; pyrimidinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; carbazolyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; triazinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; and N(Ph).sub.2.

15. The organic electroluminescent device according to claim 1, wherein the depopulation agent S.sup.B consists of a structure according to Formula 1s ##STR00073## wherein n is at each occurrence independently from another 1 or 2; X.sup.s is at each occurrence independently from another selected CN or CF.sub.3; Ar.sup.EWG is at each occurrence independently from another a structure according to one of Formulas IIsa to IIsm ##STR00074## wherein #.sup.s represents the binding site of the single bond linking Ar.sup.EWG to the substituted central phenyl ring of Formula 1s; R.sup.t is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, C.sub.1-C.sub.5-alkyl, wherein one or more hydrogen atoms are optionally substituted by deuterium, and C.sub.6-C.sub.18-aryl, which is optionally substituted with one or more substituents R.sup.6s; R.sup.s is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R.sup.5s).sub.2, OR.sup.5s, SR.sup.5s, Si(R.sup.5s).sub.3, CF.sub.3, CN, F, C.sub.1-C.sub.40-alkyl which is optionally substituted with one or more substituents R.sup.5s and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5sC═CR.sup.5s, C≡C, Si(R.sup.5s).sub.2, Ge(R.sup.5s).sub.2, Sn(R.sup.5s).sub.2, C═O, C═S, C═Se, C═NR.sup.5s, P(═O)(R.sup.5s), SO, SO.sub.2, NR.sup.5s, O, S, or CONR.sup.5s; C.sub.1-C.sub.40-thioalkoxy which is optionally substituted with one or more substituents R.sup.5s and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5sC═CR.sup.5s, C≡C, Si(R.sup.5s).sub.2, Ge(R.sup.5s).sub.2, Sn(R.sup.5s).sub.2, C═O, C═S, C═Se, C═NR.sup.5s, P(═O)(R.sup.5s), SO, SO.sub.2, NR.sup.5s, O, S, or CONR.sup.5s; and C.sub.6-C.sub.60-aryl which is optionally substituted with one or more substituents R.sup.5s; C.sub.3-C.sub.57-heteroaryl which is optionally substituted with one or more substituents R.sup.5s; R.sup.5s is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R.sup.6s).sub.2, OR.sup.6s, SR.sup.6s, Si(R.sup.6s).sub.3, CF.sub.3, CN, F, C.sub.1-C.sub.40-alkyl which is optionally substituted with one or more substituents R.sup.6s and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.6sC═CR.sup.6s, C≡C, Si(R.sup.6s).sub.2, Ge(R.sup.6s).sub.2, Sn(R.sup.6s).sub.2, C═O, C═S, C═Se, C═NR.sup.6s, P(═O)(R.sup.6s), SO, SO.sub.2, NR.sup.6s, O, S, or CONR.sup.6s; C.sub.6-C.sub.60-aryl which is optionally substituted with one or more substituents R.sup.6s; and C.sub.3-C.sub.57-heteroaryl which is optionally substituted with one or more substituents R.sup.6s; R.sup.6s is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, OPh, CF.sub.3, CN, F; C.sub.1-C.sub.5-alkyl, wherein one or more hydrogen atoms are optionally, independently from each other substituted by deuterium, CN, CF.sub.3, or F; C.sub.1-C.sub.5-alkoxy, wherein one or more hydrogen atoms are optionally, independently from each other substituted by deuterium, CN, CF.sub.3, or F; C.sub.1-C.sub.5-thioalkoxy, wherein one or more hydrogen atoms are optionally, independently from each other substituted by deuterium, CN, CF.sub.3, or F; C.sub.6-C.sub.18-aryl which is optionally substituted with one or more C.sub.1-C.sub.5-alkyl substituents; C.sub.3-C.sub.17-heteroaryl which is optionally substituted with one or more C.sub.1-C.sub.5-alkyl substituents; N(C.sub.6-C.sub.18-aryl).sub.2; N(C.sub.3-C.sub.17-heteroaryl).sub.2; and N(C.sub.3-C.sub.17-heteroaryl)(C.sub.6-C.sub.18-aryl); R.sup.d is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R.sup.5s).sub.2, OR.sup.5s, SR.sup.5s, Si(R.sup.5s).sub.3, CF.sub.3, CN, F, C.sub.1-C.sub.40-alkyl which is optionally substituted with one or more substituents R.sup.5s and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5sC═CR.sup.5s, C≡C, Si(R.sup.5s).sub.2, Ge(R.sup.5s).sub.2, Sn(R.sup.5s).sub.2, C═O, C═S, C═Se, C═NR.sup.5s, P(═O)(R.sup.5s), SO, SO.sub.2, NR.sup.5s, O, S, or CONR.sup.5s; C.sub.1-C.sub.40-thioalkoxy which is optionally substituted with one or more substituents RSs and wherein one or more non-adjacent CH.sub.2-groups are optionally substituted by R.sup.5sC═CR.sup.5s, C≡C, Si(R.sup.5s).sub.2, Ge(R.sup.5s).sub.2, Sn(R.sup.5s).sub.2, C═O, C═S, C═Se, C═NR.sup.5s, P(═O)(R.sup.5s), SO, SO.sub.2, NR.sup.5s, O, S, or CONR.sup.5s; and C.sub.6-C.sub.60-aryl which is optionally substituted with one or more substituents R.sup.5s; C.sub.3-C.sub.57-heteroaryl which is optionally substituted with one or more substituents R.sup.5s; wherein the substituents R.sup.s or R.sup.5s independently from each other optionally may form a mono- or polycyclic, (hetero)aliphatic, (hetero)aromatic, benzo-fused ring system, or a combination thereof with one or more substituents R.sup.s or R.sup.5s; and wherein the one or more substituents R.sup.d independently from each other optionally may form a mono- or polycyclic, (hetero)aliphatic, (hetero)aromatic benzo-fused ring system, or a combination thereof with one or more substituents R.sup.d.

16. The organic electroluminescent device according to claim 15, wherein n=2 and X.sup.s is CN.

17. The organic electroluminescent device according to claim 15, wherein R.sup.s is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, Me, .sup.iPr, .sup.tBu, CN, CF.sub.3; Ph, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; pyridinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; pyrimidinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; carbazolyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; triazinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph; and N(Ph).sub.2.

Description

EXAMPLES

(1) Cyclic Voltammetry

(2) Cyclic voltammograms of solutions having concentration of 10-3 mol/1 of the organic molecules in dichloromethane or a suitable solvent and a suitable supporting electrolyte (e.g. 0.1 mol/1 of tetrabutylammonium hexafluorophosphate) are measured. The measurements are conducted at room temperature and under nitrogen atmosphere with a three-electrode assembly (Working and counter electrodes: Pt wire, reference electrode: Pt wire) and calibrated using FeCp.sub.2/FeCp.sub.2.sup.+ as internal standard. HOMO data was corrected using ferrocene as internal standard against SCE.

(3) Density Functional Theory Calculation

(4) Molecular structures are optimized employing the BP86 functional and the resolution of identity approach (RI). Excitation energies are calculated using the (BP86) optimized structures employing Time-Dependent DFT (TD-DFT) methods. Orbital and excited state energies are calculated with the B3LYP functional. Def2-SVP basis sets (and a m4-grid for numerical integration were used. The Turbomole program package was used for all calculations.

(5) Photophysical Measurements

(6) Sample pretreatment: Spin-coating

(7) Apparatus: Spin150, SPS euro.

(8) The sample concentration is 10 mg/ml, dissolved in a suitable solvent.

(9) Program: 1) 3 s at 400 U/min, 20 s at 1000 U/min at 1000 Upm/s. 3) 10 s at 4000 U/min at 1000 Upm/s. After coating, the films are tried at 70° C. for 1 min. Photoluminescence spectroscopy and TCSPC (Time-correlated single-photon counting)

(10) Steady-state emission spectroscopy is recorded using a Horiba Scientific, Modell FluoroMax-4 equipped with a 150 W Xenon-Arc lamp, excitation- and emissions monochromators and a Hamamatsu R928 photomultiplier and a time-correlated single-photon counting option. Emissions and excitation spectra are corrected using standard correction fits.

(11) Excited state lifetimes are determined employing the same system using the TCSPC method with FM-2013 equipment and a Horiba Yvon TCSPC hub.

(12) Excitation Sources:

(13) NanoLED 370 (wavelength: 371 nm, puls duration: 1.1 ns)

(14) NanoLED 290 (wavelength: 294 nm, puls duration: <1 ns)

(15) SpectraLED 310 (wavelength: 314 nm)

(16) SpectraLED 355 (wavelength: 355 nm).

(17) Data analysis (exponential fit) was done using the software suite DataStation and DAS6 analysis software. The fit is specified using the chi-squared-test.

(18) Photoluminescence Quantum Yield Measurements

(19) For photoluminescence quantum yield (PLQY) measurements an Absolute PL Quantum Yield Measurement C9920-03G system (Hamamatsu Photonics) is used. Quantum yields and CIE coordinates were determined using the software U6039-05 version 3.6.0.

(20) Emission maxima are given in nm, quantum yields Φ in % and CIE coordinates as x,y values.

(21) PLQY was determined using the following protocol: 1) Quality assurance: Anthracene in ethanol (known concentration) is used as reference 2) Excitation wavelength: the absorption maximum of the organic molecule is determined and the molecule is excited using this wavelength 3) Measurement Quantum yields are measured for sample of solutions or films under nitrogen atmosphere. The yield is calculated using the equation:

(22) ${\Phi }_{\mathrm{PL}}=\frac{n_{\mathrm{photon}},\mathrm{emited}}{n_{\mathrm{photon}},\mathrm{absorbed}}=\frac{\int \frac{\lambda }{\mathrm{hc}}\left[{\mathrm{Int}}_{\mathrm{emitted}}^{\mathrm{sample}}\left(\lambda \right)-{\mathrm{Int}}_{\mathrm{absorbed}}^{\mathrm{sample}}\left(\lambda \right)\right]d\lambda }{\int \frac{\lambda }{\mathrm{hc}}\left[{\mathrm{Int}}_{\mathrm{emitted}}^{\mathrm{reference}}\left(\lambda \right)-{\mathrm{Int}}_{\mathrm{absorbed}}^{\mathrm{reference}}\left(\lambda \right)\right]d\lambda }$ wherein n.sub.photon denotes the photon count and Int. is the intensity.
Production and Characterization of Organic Electroluminescence Devices

(23) Via vacuum-deposition methods OLED devices comprising organic molecules according to the invention can be produced. If a layer contains more than one compound, the weight-percentage of one or more compounds is given in %. The total weight-percentage values amount to 100%, thus if a value is not given, the fraction of this compound equals to the difference between the given values and 100%.

(24) The not fully optimized OLEDs are characterized using standard methods and measuring electroluminescence spectra, the external quantum efficiency (in %) in dependency on the intensity, calculated using the light detected by the photodiode, and the current. The OLED device lifetime is extracted from the change of the luminance during operation at constant current density. The LT50 value corresponds to the time, where the measured luminance decreased to 50% of the initial luminance, analogously LT80 corresponds to the time point, at which the measured luminance decreased to 80% of the initial luminance, LT97 to the time point, at which the measured luminance decreased to 97% of the initial luminance etc.

(25) Accelerated lifetime measurements are performed (e.g. applying increased current densities). Exemplarily LT80 values at 500 cd/m.sup.2 are determined using the following equation:

(26) $\mathrm{LT}80\left(500\frac{{\mathrm{cd}}^2}{m^2}\right)=\mathrm{LT}80\left(L_0\right){\left(\frac{L_0}{500\frac{{\mathrm{cd}}^2}{m^2}}\right)}^{1.6}$
wherein L.sub.0 denotes the initial luminance at the applied current density.

(27) The values correspond to the average of several pixels (typically two to eight), the standard deviation between these pixels is given. Figures show the data series for one OLED pixel.

Examples D1 and D2 and Comparative Examples C1

(28) ##STR00067##

(29) TABLE-US-00001 λ.sub.max.sup.PMMA [nm] HOMO [eV] LUMO [eV] S1 [eV] T1 [eV] mCBP −6.02 −2.34 3.60 2.95 TADF1 469 −5.81 −2.86 2.94 MAT1 450 −6.14 −3.11 3.03 2.75 MAT2 465 −6.16 −3.16 2.94 2.83

(30) TABLE-US-00002 Layer Thickness D1 D2 C2 10  100 nm  Al Al Al 9  2 nm Liq Liq Liq 8 20 nm NBPhen NBPhen NBPhen 7 10 nm HBL1 HBL1 HBL1 6 50 nm TADF1 (20%): TADF1 (20%): TADF1 (20%): MAT1 (5%): MAT2 (5%): mCBP (80%) mCBP (75%) mCBP (75%) 5 10 nm mCBP mCBP mCBP 4 10 nm TCTA TCTA TCTA 3 40 nm NPB NPB NPB 2  5 nm HAT-CN HAT-CN HAT-CN 1 50 nm ITO ITO ITO substrate glass glass glass

(31) Device D1 yielded an external quantum efficiency (EQE) at 1000 cd/m.sup.2 of 15.4±0.5%. The LT80 value at 500 cd/m.sup.2 was determined to be 81 h from accelerated lifetime measurements. The emission maximum is at 472 nm with a FWHM of 67 nm at 10 mA/cm.sup.2. The corresponding CIEy value is 0.24.

(32) Device D2 yielded an external quantum efficiency (EQE) at 1000 cd/m.sup.2 of 12.6±0.2%. The LT80 value at 500 cd/m.sup.2 was determined to be 57 h from accelerated lifetime measurements. The emission maximum is at 471 nm with a FWHM of 67 nm at 10 mA/cm.sup.2. The corresponding CIEy value is 0.25.

(33) Comparative device C1 comprises an emitting layer containing only TADF1 as emitter and mCBP as host material. The EQE at 1000 cd/m.sup.2 is at 9.5±0.1%, thus lower than for D1 and D2 and the lifetime is significantly shorter (LT80 at 500 cd/m.sup.2=29 h). The emission maximum appears at 475 nm with a FWHM of 68 nm at 10 mA/cm.sup.2. The corresponding CIEy value is 0.24.