Organic EL device having hole-injection layer doped with metallic oxide

1. An organic EL device comprising a substrate having at least a light-reflective anode, a hole-injection layer, a hole-transport layer, a light-emitting layer; an electron-transport layer and a light-transmitting cathode, which are sequentially laminated on the substrate, wherein the light-reflective anode side of hole-injection layer is doped with a metallic oxide, wherein the metallic oxide to be doped is V 2 O 5 or MoO3.

2. The organic EL device of claim 1 , wherein the light-reflective anode comprises Al or Al alloy.

3. The organic EL device of claim 1 , wherein an anode buffer layer comprising a metal having a work function of 4.3 eV or more or an oxide thereof is sandwiched between the light-reflective anode and the hole-injection layer.

4. The organic EL device of claim 3 , wherein an anode buffer layer comprising a material selected from the group consisting of MoO 3 , V 2 O 5 , NiO, Mo and Ni is sandwiched between the light-reflective anode and the hole-injection layer.

5. The organic EL device of claim 1 , wherein the light-reflective anode is subjected to a UV ozone surface treatment or an O 2 plasma surface treatment.

6. The organic EL device of claim 3 , wherein the anode buffer layer is subjected to a UV ozone surface treatment or an O 2 plasma surface treatment.

7. The organic EL device of claim 1 , wherein the doped metallic oxide is not present in the hole-transport layer side of the hole-injection layer.

8. The organic EL device of claim 1 , wherein the light-transmitting cathode is a semi-transparent cathode comprising Ag or Ag alloy.

9. The organic EL device of claim 8 , wherein the electron-injection layer comprising an alkaline metal compound and a thin film comprising Al having a thickness of 0.5 nm to 3 nm is sandwiched between the semi-transparent cathode comprising Ag or Ag alloy and the electron-transport layer.

10. The organic EL device of claim 8 , wherein a capping layer comprising ZnS is laminated on the semi-transparent cathode comprising Ag or Ag alloy.

11. The organic EL device of claim 1 , wherein the substrate is a flexible substrate.

12. An organic EL device comprising a substrate having at least a light-reflective anode, a hole-injection layer comprising a first hole-injection layer, and a second hole-injection layer, a hole-transport layer, a light-emitting layer, an electron-transport layer and a light-transmitting cathode, which are sequentially laminated in this order on the substrate, wherein the first hole-injection layer is doped with a metallic oxide.

13. The organic EL device of claim 12 , wherein the metallic oxide to be doped is V 2 O 5 or MoO 3 .

14. The organic EL device of claim 12 , wherein the light-reflective anode comprises Al or Al alloy.

15. The organic EL device of claim 12 , wherein an anode buffer layer comprising a metal having a work function of 4.3 eV or more or an oxide thereof is sandwiched between the light-reflective anode and the first hole-injection layer.

16. The organic EL device of claim 15 , wherein an anode buffer layer comprising a material selected from the group consisting of MoO 3 , V 2 O 5 , NiO, Mo and Ni is sandwiched between the light-reflective anode and the first hole-injection layer.

17. The organic EL device of claim 12 , wherein the light reflective anode is subjected to a UV ozone surface treatment or an O 2 plasma surface treatment.

18. The organic EL device of claim 15 , wherein the anode buffer layer is subjected to a UV ozone surface treatment or an O 2 plasma surface treatment.

19. The organic EL device of claim 12 , wherein the doped metallic oxide is not present in the second hole-injection layer.

20. The organic EL device of claim 12 , wherein the light-transmitting cathode is a semi-transparent cathode comprising Ag or Ag alloy.

21. The organic EL device of claim 12 , wherein the substrate is a flexible substrate.