Organic electroluminescent materials and devices

1. An organic light emitting device (OLED), comprising:

an anode;

a cathode; and

an organic emissive layer disposed between the anode and the cathode, the organic emissive layer comprising:

a first host having a highest occupied molecular orbital (HOMO) energy, a lowest unoccupied molecular orbital (LUMO) energy, and a T 1 triplet energy, wherein the first host is an electron transporting host; and

an emitter having a highest occupied molecular orbital (HOMO) energy, a lowest unoccupied molecular orbital (LUMO) energy, and a T 1 triplet energy, wherein the emitter is a blue emitter;

wherein the emitter is a phosphorescent metal complex;

wherein E H1T , the T 1 triplet energy of the first host, is higher than E ET , the T 1 triplet energy of the emitter;

wherein E ET is at least 2.50 eV;

wherein the LUMO energy of the first host is higher than the HOMO energy of the emitter;

wherein the absolute value of the difference between the HOMO energy of the emitter and the LUMO energy of the first host is ΔE1;

wherein a≤ΔE1−E ET ≤b;

wherein a≥0.05 eV, and b≤0.60 eV;

wherein the emitter is selected from the group consisting of:

wherein L is selected from the group consisting of BR, NR, PR, O, S, CRR′″, SiRR′″, alkyl, cycloalkyl, aryl, and heteroaryl,

wherein each R A to R F can represent from mono substitution to the possible maximum number of substitutions, or no substitution;

wherein R, R′″, R B to R F are each independently a hydrogen or a substitution selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, boryl, and combinations thereof;

wherein R A is aryl, which can be further substituted by one or more substitutions, each independently selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, boryl, and combinations thereof;

wherein any two R, R′″, R A to R F can be fused or joined to form a ring or form a multidentate ligand.

2. The OLED of claim 1 , wherein R, R′″, and R B to R F are each independently a hydrogen or a substituent selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, sulfanyl, nitrile, and combinations thereof.

3. The OLED of claim 1 , wherein at least one of R, R′″, R A to R F comprises a chemical group containing at least three 6-membered aromatic rings that are not fused next to each other.

4. The OLED of claim 1 , wherein the absolute value of the difference between the highest HOMO energy and the lowest LUMO energy among all components in the emissive layer is larger than E ET by at least a.

5. The OLED of claim 1 , wherein the OLED further comprises a second host;

wherein E H2T , the T 1 triplet energy of the second host, is higher than E ET .

6. The OLED of claim 5 , wherein the HOMO energy of the second host is lower than the HOMO energy of the first host, the LUMO energy of the second host is higher than the LUMO energy of the first host.

7. The OLED of claim 5 , wherein the HOMO energy of the second host is higher than the HOMO energy of the first host, the LUMO energy of the second host is higher than the LUMO energy of the first host.

8. The OLED of claim 5 , wherein the second host is a hole transporting host.

9. The OLED of claim 1 , wherein the first host comprises at least one chemical group selected from the group consisting of pyridine, pyrimidine, pyrazine, triazine, imidazole, aza-triphenylene, aza-carbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene.

10. The OLED of claim 1 , wherein the first host comprises at least one chemical group consisting 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group.

11. The OLED of claim 1 , wherein the emitter is selected from the group consisting of:

12. The OLED of claim 1 , wherein R A comprises a chemical group containing at least three 6-membered aromatic rings that are not fused next to each other.

13. The OLED of claim 1 , wherein a is 0.1 eV, and b is 0.50 eV.

14. The OLED of claim 1 , wherein E ET is at least 2.60 eV.

15. The OLED of claim 1 , wherein L is O.

16. The OLED of claim 1 , wherein the OLED further comprises a delayed fluorescent emitter.

17. An organic light emitting device (OLED), comprising:

an anode;

a cathode; and

an organic emissive layer disposed between the anode and the cathode, the organic emissive layer comprising:

a first host having a highest occupied molecular orbital (HOMO) energy, a lowest unoccupied molecular orbital (LUMO) energy, and a T 1 triplet energy, wherein the first host is an electron transporting host; and

an emitter having a highest occupied molecular orbital (HOMO) energy, a lowest unoccupied molecular orbital (LUMO) energy, and a T 1 triplet energy;

wherein the emitter is a delayed fluorescent emitter;

wherein E H1T , the T 1 triplet energy of the first host, is higher than E ET , the T 1 triplet energy of the emitter;

wherein E ET is at least 2.50 eV;

wherein the LUMO energy of the first host is higher than the HOMO energy of the emitter;

wherein the absolute value of the difference between the HOMO energy of the emitter and the LUMO energy of the first host is ΔE1;

wherein a≤ΔE1−E ET ≤b;

wherein a≥0.05 eV, and b≤0.60 eV.

18. The OLED of claim 17 , wherein the first host comprises at least one chemical group selected from the group consisting of pyridine, pyrimidine, pyrazine, triazine, imidazole, aza-triphenylene, aza-carbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, and a group consisting 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group.

19. The OLED of claim 17 , wherein the OLED further comprises a phosphorescent metal complex.

20. A consumer product comprising an organic light emitting device (OLED) comprising:

an anode;

a cathode; and

an organic emissive layer disposed between the anode and the cathode, the organic emissive layer comprising:

a first host having a highest occupied molecular orbital (HOMO) energy, a lowest unoccupied molecular orbital (LUMO) energy, and a T 1 triplet energy, wherein the first host is an electron transporting host; and

an emitter having a highest occupied molecular orbital (HOMO) energy, a lowest unoccupied molecular orbital (LUMO) energy, and a T 1 triplet energy, wherein the emitter is a blue emitter;

wherein the emitter is selected from the group consisting of a phosphorescent metal complex, and a delayed fluorescent emitter;

wherein E H1T , the T 1 triplet energy of the first host, is higher than E ET , the T 1 triplet energy of the emitter;

wherein E ET is at least 2.50 eV;

wherein the LUMO energy of the first host is higher than the HOMO energy of the emitter;

wherein the absolute value of the difference between the HOMO energy of the emitter and the LUMO energy of the first host is ΔE1;

wherein a≤ΔE1−E ET ≤b;

wherein a≥0.05 eV, and b≤0.60 eV;

wherein the phosphorescent metal complex is selected from the group consisting of:

wherein L is selected from the group consisting of BR, NR, PR, O, S, CRR′″, SiRR′″, alkyl, cycloalkyl, aryl, and heteroaryl,

wherein each R A to R F can represent from mono substitution to the possible maximum number of substitutions, or no substitution;

wherein R, R″″, R B to R F are each independently a hydrogen or a substitution selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, boryl, and combinations thereof;

wherein R A is aryl, which can be further substituted by one or more substitutions, each independently selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, boryl, and combinations thereof; and

wherein any two R, R′″, R A to R F can be fused or joined to form a ring or form a multidentate ligand.