Organic light emitting display device having layer to control charge transfer
Discussed is an organic light emitting display device. The organic light emitting display device may include an anode on a substrate, a first emission part that is disposed on the anode and includes a first emission layer and a first electron transfer layer, a second emission part that is disposed on the first emission part and includes a second emission layer and a second electron transfer layer, and a cathode on the second emission part. At least one among the first electron transfer layer and the second electron transfer layer may include a first material and a second material, and an absolute value of a LUMO energy level of the first material may be larger than an absolute value of a LUMO energy level of the second material.
1. An organic light emitting display device, comprising:
an anode on a substrate;
a first hole transfer layer on the anode;
an emission control layer on the first hole transfer layer;
a first emission layer on the emission control layer;
a first electron transfer layer on the first emission layer;
an N-type charge generation layer on the first electron transfer layer;
a second hole transfer layer on the N-type charge generation layer;
a second emission layer on the second hole transfer layer;
a second electron transfer layer on the second emission layer, the second electron transfer layer having a first material and a second material; and
a cathode on the second electron transfer layer,
wherein a difference between a lowest unoccupied molecular orbital (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 absolute value of a LUMO energy level of the first material is within a range of 2.91 eV to 3.40 eV and an absolute value of a LUMO energy level of the second material is within a range of 2.60 eV to 2.90 eV.
3. 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.
4. The organic light emitting display device of claim 1 , wherein a content of the second material is more than 50 wt % of a content of the first material.
5. The organic light emitting display device of claim 1 , wherein an absolute value of a highest occupied molecular orbital (HOMO) energy level of the emission control layer is 0.10 eV to 0.50 eV greater than an absolute value of a HOMO energy level of the first hole transfer layer.
6. The organic light emitting display device of claim 1 , 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.
7. 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.
8. The organic light emitting display device of claim 1 , wherein the first hole transfer layer includes a P-type hole transfer layer doped with a P-type dopant.
9. The organic light emitting display device of claim 1 , wherein the first emission layer and the second emission layer include one among a red emitting layer, a green emitting layer, and a blue emitting layer.
10. The organic light emitting display device of claim 1 , wherein the first emission layer and the second emission layer emit light having a same color.
11. An organic light emitting display device, comprising:
a plurality of pixels on a substrate, a plurality of pixels having a red subpixel, a green subpixel, and a blue subpixel;
an anode on the substrate;
a first hole transfer layer on the anode;
an emission control layer on the first hole transfer layer;
a first emission layer on the emission control layer in the red subpixel, the green subpixel, and the blue subpixel, the red subpixel having a first red emission layer,
a first electron transfer layer on first emission layer;
an N-type charge generation layer on the first electron transfer layer;
a second hole transfer layer on the N-type charge generation layer;
a second emission layer on the second hole transfer layer in the red subpixel, the green subpixel, and the blue subpixel;
a second electron transfer layer on the second emission layer, the second electron transfer layer having a first material and a second material; and
a cathode on the second electron transfer layer,
wherein a difference between a lowest unoccupied molecular orbital (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.
12. The organic light emitting display device of claim 11 , wherein an absolute value of a highest occupied molecular orbital (HOMO) energy level of the emission control layer is 0.10 eV to 0.50 eV greater than an absolute value of a HOMO energy level of the first hole transfer layer.
13. The organic light emitting display device of claim 11 , 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.
14. The organic light emitting display device of claim 11 , 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.
15. The organic light emitting display device of claim 11 , wherein an absolute value of a LUMO energy level of the first material is within a range of 2.91 eV to 3.40 eV and an absolute value of a LUMO energy level of the second material is within a range of 2.60 eV to 2.90 eV.
16. The organic light emitting display device of claim 11 , wherein the first material comprises one among anthracene derivatives, triazine derivatives, and carbozole derivatives.
17. The organic light emitting display device of claim 11 , wherein a ratio of the first material and the second material is 1:1 in wt %.
18. The organic light emitting display device of claim 11 , wherein a content of the second material is more than 50 wt % of a content of the first material.
19. The organic light emitting display device of claim 11 , further comprising a capping layer on the cathode.
20. An organic light emitting display device, comprising:
an anode on a substrate;
a first hole transfer layer on the anode;
a first emission control layer on the first hole transfer layer;
a first emission layer on the first emission control layer;
a first electron transfer layer on the first emission layer;
an N-type charge generation layer on the first electron transfer layer;
a second hole transfer layer on the N-type charge generation layer;
a second emission control layer on the second hole transfer layer;
a second emission layer on the second emission control layer;
a second electron transfer layer on the second emission layer, the second electron transfer layer having a first material and a second material; and
a cathode on the second electron transfer layer,
wherein a difference between a lowest unoccupied molecular orbital (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.
21. The organic light emitting display device of claim 20 , 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 greater than an absolute value of a HOMO energy level of the first hole transfer layer.
22. The organic light emitting display device of claim 20 , 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.
23. The organic light emitting display device of claim 20 , 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 greater than an absolute value of a HOMO energy level of the second hole transfer layer.
24. The organic light emitting display device of claim 20 , 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.
25. The organic light emitting display device of claim 20 , 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.
26. The organic light emitting display device of claim 20 , wherein an absolute value of a LUMO energy level of the first material is within a range of 2.91 eV to 3.40 eV and an absolute value of a LUMO energy level of the second material is within a range of 2.60 eV to 2.90 eV.
27. The organic light emitting display device of claim 20 , wherein a content of the second material is more than 50 wt % of a content of the first material.
28. The organic light emitting display device of claim 20 , wherein the first emission layer and the second emission layer include one among a red emitting layer, a green emitting layer, and a blue emitting layer.
29. The organic light emitting display device of claim 20 , wherein the first emission layer and the second emission layer emit light having a same color.