Organic light emitting display device having layer to control charge transfer

1. An organic light emitting display device, comprising:

an anode on a substrate;

a first emission part on the anode, the first emission part including a first emission layer and a first electron transfer layer;

a second emission part on the first emission part, the second emission part including a second emission layer and a second electron transfer layer;

an N-type charge generation layer between the first emission part and the second emission part; and

a cathode on the second emission part,

wherein at least one among the first electron transfer layer and the second electron transfer layer comprises a first material and a second material, and an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level of the first material is larger than an absolute value of a LUMO energy level of the second material,

wherein the first material has an absolute value of the LUMO energy level within a first range of 2.91 eV to 3.40 eV and the second material has an absolute value of the LUMO energy level within a second range of 2.60 eV to 2.90 eV,

wherein the first range and the second range do not overlap,

wherein the first electron transfer layer comprises one among the first material and the second material, and the second electron transfer layer comprises the first material and the second material, and

wherein a difference between a LUMO energy level of the first electron transfer layer and a LUMO energy level of the N-type charge generation layer is 0.50 eV to 1.00 eV.

2. The organic light emitting display device of claim 1 , wherein an amount of the second material is higher than an amount of the first material.

3. The organic light emitting display device of claim 1 , wherein in the first electron transfer layer or the second electron transfer layer, a content of the second material is more than 50 wt %.

4. The organic light emitting display device of claim 1 , wherein the first material and the second material are mixed through co-deposition.

5. The organic light emitting display device of claim 1 , further comprising:

a second hole transfer layer on the first electron transfer layer; and

a second emission control layer between the second hole transfer layer and the second emission layer.

6. The organic light emitting display device of claim 5 , wherein an absolute value of a highest occupied molecular orbital (HOMO) energy level of the second emission control layer is 0.10 eV to 0.50 eV larger than an absolute value of a HOMO energy level of the second hole transfer layer.

7. The organic light emitting display device of claim 5 , wherein a hole mobility of the second emission control layer is 1.0×10 −1 to 1.0×10 −2 times lower than a hole mobility of the second hole transfer layer.

8. The organic light emitting display device of claim 1 ,

wherein the first electron transfer layer comprises the first material and the second material.

9. The organic light emitting display device of claim 8 , further comprising:

a first hole transfer layer on the anode; and

a first emission control layer between the first hole transfer layer and the first emission layer.

10. The organic light emitting display device of claim 9 , wherein an absolute value of a highest occupied molecular orbital (HOMO) energy level of the first emission control layer is 0.10 eV to 0.50 eV larger than an absolute value of a HOMO energy level of the first hole transfer layer.

11. The organic light emitting display device of claim 9 , wherein a hole mobility of the first emission control layer is 1.0×10 −1 to 1.0×10 −2 times lower than a hole mobility of the first hole transfer layer.

12. The organic light emitting display device of claim 8 , further comprising:

a second hole transfer layer on the first electron transfer layer; and

a second emission control layer between the second hole transfer layer and the second emission layer.

13. The organic light emitting display device of claim 12 , wherein an absolute value of a highest occupied molecular orbital (HOMO) energy level of the second emission control layer is 0.10 eV to 0.50 eV larger than an absolute value of a HOMO energy level of the second hole transfer layer.

14. The organic light emitting display device of claim 12 , wherein a hole mobility of the second emission control layer is 1.0×10 −1 to 1.0×10 −2 times lower than a hole mobility of the second hole transfer layer.

15. The organic light emitting display device of claim 1 , wherein an absolute value of the LUMO energy level of the first electron transfer layer is within a range of 2.00 eV to 2.50 eV, and an absolute value of the LUMO energy level of the N-type charge generation layer is within a range of 2.90 eV to 3.20 eV.

16. The organic light emitting display device of claim 1 , further comprising:

an emission control layer under at least one of the first emission layer and the second emission layer.

17. The organic light emitting display device of claim 1 , wherein the first emission layer and the second emission layer emit light having the same color.

18. The organic light emitting display device of claim 1 , wherein a ratio of the first material and the second material is 1:1 in wt %.

19. An organic light emitting display device, comprising:

an anode on a substrate;

a first emission part on the anode, the first emission part including a first hole transfer layer, a first emission layer, and a first electron transfer layer;

a second emission part on the first emission part, the second emission part including a second hole transfer layer, a second emission layer, and a second electron transfer layer;

an N-type charge generation layer between the first emission part and the second emission part; and

a cathode on the second emission part,

wherein at least one among the first emission part and the second emission part comprises an emission control layer having an absolute value of a highest occupied molecular orbital (HOMO) energy level which is larger than an absolute value of a HOMO energy level of the first hole transfer layer or the second hole transfer layer,

wherein at least one among the first electron transfer layer and the second electron transfer layer includes at least two materials that are mixed through co-deposition,

wherein a first material of the at least two materials has an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level within a first range of 2.91 eV to 3.40 eV and a second material of the at least two materials has an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level within a second range of 2.60 eV to 2.90 eV,

wherein the first range and the second range do not overlap,

wherein the first electron transfer layer comprises one among the at least two materials, and the second electron transfer layer comprises the at least two materials, and

wherein a difference between a LUMO energy level of the first electron transfer layer and a LUMO energy level of the N-type charge generation layer is 0.50 eV to 1.00 eV.

20. The organic light emitting display device of claim 19 , wherein the absolute value of the HOMO energy level of the emission control layer is 0.10 eV to 0.50 eV larger than the absolute value of the HOMO energy level of the first hole transfer layer or the second hole transfer layer.

21. The organic light emitting display device of claim 19 , wherein a hole mobility of the emission control layer is 1.0×10 −1 to 1.0×10 −2 times lower than a hole mobility of the first hole transfer layer or the second hole transfer layer.

22. The organic light emitting display device of claim 19 , wherein a material having a small absolute value of the LUMO energy level among the at least two materials is higher in amount than another material having a large absolute value of the LUMO energy level among the at least two materials.

23. The organic light emitting display device of claim 22 , wherein the emission control layer is provided in the second emission part and between the second hole transfer layer and the second emission layer.

24. The organic light emitting display device of claim 19 , wherein each of the first electron transfer layer and the second electron transfer layer comprises the at least two materials, and a material having a small absolute value of the LUMO energy level among the at least two materials is higher in amount than another material having a large absolute value of the LUMO energy level among the at least two materials.

25. The organic light emitting display device of claim 24 , wherein the emission control layer is provided in the first emission part and the second emission part, between the first hole transfer layer and the first emission layer, and between the second hole transfer layer and the second emission layer.

26. The organic light emitting display device of claim 19 , wherein the emission control layer is provided in the first emission part and between the first hole transfer layer and the first emission layer.

27. The organic light emitting display device of claim 19 , wherein the emission control layer is provided in the second emission part and between the second hole transfer layer and the second emission layer.

28. The organic light emitting display device of claim 19 , wherein the first electron transfer layer comprises one among anthracene derivatives, triazine derivatives, and carbozole derivatives.

29. The organic light emitting display device of claim 19 , wherein a ratio of the first material and the second material is 1:1 in wt %.