Organic electroluminescence device, organic electroluminescence unit, and electronic apparatus

1. An organic electroluminescence device comprising, in order:

a first electrode;

a hole transport layer, that is a coated film, which is formed by coating and drying a solution containing, as a solute, a hole transporting material having an insoluble group, the hole transport layer being insoluble to an organic solvent or water;

a single organic light-emitting layer that is another coated film;

an electron transport layer; and

a second electrode, wherein

the organic light-emitting layer has a light emission region and a non-emission region,

the light emission region and the non-emission region each include a host material and a dopant material, and

greater than 50% of the light emission region is in a half of the organic light-emitting layer that is closer to the electron transport layer than to the hole transport layer.

2. The organic electroluminescence device according to claim 1 , wherein the electron transport layer has an energy gap that is larger than an energy gap of the organic light-emitting layer.

3. The organic electroluminescence device according to claim 2 , wherein the electron transport layer is a deposited film.

4. The organic electroluminescence device according to claim 1 , wherein the organic light-emitting layer has hole mobility that is larger than electron mobility.

5. The organic electroluminescence device according to claim 1 , wherein the organic light-emitting layer has a hole current that is larger than an electron current of the organic light-emitting layer.

6. The organic electroluminescence device according to claim 5 , wherein a position of the light emission region becomes closer to an interface of the organic light-emitting layer and the electron transport layer as a quotient of the hole current divided by the electron current becomes larger.

7. The organic electroluminescence device according to claim 1 , wherein the organic light-emitting layer is made of an organic light-emitting material that has a molecular orientation degree specified by a parameter S′, the parameter S′ satisfying the following inequality:

0.66< S′< 0.75, provided that

S ′={(2× ko )/( ke+ 2 ko )}

where ko denotes an extinction coefficient in a film-plane direction of the organic light-emitting layer, and ke denotes an extinction coefficient in a film-thickness direction of the organic light-emitting layer.

8. The organic electroluminescence device according to claim 7 , wherein a position of the light emission region becomes closer to an interlace of the organic light-emitting layer and the electron transport layer as the parameter S′ comes closer to 0.66.

9. An electronic apparatus provided with an organic electroluminescence unit, the organic electroluminescence unit having a plurality of organic electroluminescence devices, one or more of the plurality of organic electroluminescence devices comprising, in order:

a first electrode;

a hole transport layer, that is a coated film, which is formed by coating and drying a solution containing, as a solute, a hole transporting material having an insoluble group, the hole transport layer being insoluble to an organic solvent or water;

a single organic light-emitting layer that is another coated film;

an electron transport layer; and

a second electrode, wherein

the organic light-emitting layer has a light emission region and a non-emission region,

the light emission region and the non-emission region each include a host material and a dopant material, and

greater than 50% of the light emission region is in a half of the organic light-emitting layer that is closer to the electron transport layer than to the hole transport layer.

10. The organic electroluminescence device according to claim 1 , wherein the hole transport layer has an energy gap that is substantially the same as an energy gap of the organic light-emitting layer.

11. The organic electroluminescence device according to claim 1 , wherein the insoluble group is selected from a group consisting of a cross-linking group and a thermal dissociation soluble group.

12. The electronic apparatus according to claim 9 , wherein the hole transport layer has an energy gap that is substantially the same as an energy gap of the organic light-emitting layer.

13. The electronic apparatus according to claim 9 , wherein the insoluble group is selected from a group consisting of a cross-linking group and a thermal dissociation soluble group.

14. The organic electroluminescence device according to claim 1 , wherein at least 90% of the light emission region is in the half of the organic light-emitting layer that is closer to the electron transport layer than to the hole transport layer.

15. An organic electroluminescence device comprising, in order:

a first electrode:

a hole transport layer, that is a coated film, which is formed by coating and drying a solution containing, as a solute, a hole transporting material having an insoluble group, the hole transport layer being insoluble to an organic solvent or water;

a single organic light-emitting layer that is another coated film;

an electron transport layer; and

a second electrode, wherein

the organic light-emitting layer has a light emission region and a non-emission region,

the light emission region and the non-emission region each include a host material and a dopant material,

the organic light-emitting layer includes a first region extending from a middle of the organic light emitting layer to the electron transport layer, and a second region extending from the middle of the organic light-emitting layer to the hole transport layer, and

greater than 50% of the light emission region is in the first region.

16. The organic electroluminescence device according to claim 15 , wherein the light emission region extends from the first region to at least a part of the second region.

17. The organic electroluminescence device according to claim 1 , wherein the light emission region is smaller than an entirety of the organic light-emitting layer.