Organic EL element having one functional layer with NaF and the other functional layer with Yb

1. An organic electroluminescence element comprising:

an anode;

an organic light emitting layer disposed on an upper side of the anode;

a first functional layer disposed over the organic light emitting layer and including NaF;

a second functional layer disposed over the first functional layer and including an organic material containing Yb; and

a cathode disposed on an upper side of the second functional layer,

wherein the second functional layer includes a first layer section, a second layer section and a third layer section that are sequentially stacked in this order from a first functional layer side, and a relation of X2<X1<X3 is satisfied, where X1, X2 and X3 are Yb contents of the first layer section, the second layer section and the third layer section, respectively.

2. The organic electroluminescence element according to claim 1 ,

wherein the first functional layer has a film thickness of 0.1 to 20 nm.

3. The organic electroluminescence element according to claim 1 ,

wherein the second functional layer has a film thickness of 5 to 150 nm.

4. The organic electroluminescence element according to claim 1 ,

wherein a transparent conductive film is formed as a third functional layer between the second functional layer and the cathode.

5. The organic electroluminescence element according to claim 4 ,

wherein the third functional layer has a film thickness of not less than 15 nm.

6. The organic electroluminescence element according to claim 4 ,

wherein a thin film including Yb and having a thickness of 0.1 to 3 nm is formed between the second functional layer and the third functional layer.

7. The organic electroluminescence element according to claim 4 ,

wherein a thin film including Yb and having a thickness of 0.1 to 3 nm is formed between the third functional layer and the cathode.

8. The organic electroluminescence element according to claim 1 ,

wherein a thin film including Yb and having a thickness of 0.1 to 5 nm is formed on an opposite side of the cathode from the organic light emitting layer.

9. The organic electroluminescence element according to claim 1 ,

wherein the anode has a light reflecting property, and the cathode has a semi-transparent property.

10. The organic electroluminescence element according to claim 9 ,

wherein light emitted from the organic light emitting layer includes a first light flux going out directly from the cathode and a second light flux going out from the cathode after being reflected by respective surfaces on an organic light emitting layer side of the anode and the cathode, and a film thickness of at least one functional layer interposed in a range from the organic light emitting layer to the cathode is set according to a wavelength of a color in which the light is emitted in such a manner that the first light flux and the second light flux resonate.

11. An organic electroluminescence element comprising:

an anode;

an organic light emitting layer disposed on an upper side of the anode;

a first functional layer disposed over the organic light emitting layer and including NaF;

a second functional layer disposed over the first functional layer and including an organic material containing Yb; and

a cathode disposed on an upper side of the second functional layer,

wherein the second functional layer includes a first layer section disposed over the first functional layer, and a second layer section disposed over the first layer section, and

Yb content of the second layer section is greater than Yb content of the first layer section.

12. An organic electroluminescence element comprising:

an anode;

an organic light emitting layer disposed on an upper side of the anode;

a first functional layer disposed over the organic light emitting layer and including NaF;

a second functional layer disposed over the first functional layer and including an organic material containing Yb; and

a cathode disposed on an upper side of the second functional layer,

wherein Yb content of the second functional layer increases continuously in going from the first functional layer toward the cathode.

13. An electronic apparatus comprising:

an organic electroluminescence display device as an image display section, the organic electroluminescence display device including

an organic electroluminescence panel in which a plurality of organic electroluminescence elements are arranged in a matrix pattern on an upper side of a substrate, the plurality of organic electroluminescence elements each including an anode, an organic light emitting layer disposed on an upper side of the anode, a first functional layer disposed over the organic light emitting layer and including NaF, a second functional layer disposed over the first functional layer and including an organic material containing Yb, and a cathode disposed on an upper side of the second functional layer, and the organic light emitting layers in at least the organic electroluminescence elements adjacent to each other in a row direction are partitioned from each other by a partition wall extending in a column direction, and

a driving section driving the organic electroluminescence panel to display an image,

wherein the second functional layer includes a first layer section, a second layer section and a third layer section that are sequentially stacked in this order from a first functional layer side, and a relation of X2<X1<X3 is satisfied, where X1, X2 and X3 are Yb contents of the first layer section, the second layer section and the third layer section, respectively.