Organic electroluminescence device, organic electroluminescence unit, and electronic apparatus
An organic electroluminescence device includes, in order, a first electrode, a hole transport layer, an organic light-emitting layer, an electron transport layer, and a second electrode. The hole transport layer is configured by a coated film. The organic light-emitting layer is configured by a coated film. 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′ satisfies an inequality: 0.66<S′<0.75, provided that S′={(2×ko)/(ke+2ko)}. In this expression, 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.
1. An organic electroluminescence device comprising, in order:
a first electrode;
a hole transport layer configured by a coated film;
an organic light-emitting layer configured by a coated film;
an electron transport layer; and
a second electrode,
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.
2. The organic electroluminescence device according to claim 1 , wherein the parameter S′ satisfies an inequality: 0.66<S′<0.72.
3. The organic electroluminescence device according to claim 2 , wherein the parameter S′ satisfies an inequality: 0.66<S′<0.69.
4. The organic electroluminescence device according to claim 1 , wherein a position of the light emission region provided in the organic light-emitting layer comes closer to the electron transport layer, as the parameter S′ comes closer to 0.66.
5. The organic electroluminescence device according to claim 1 , wherein the hole transport layer comprises an insolubilized hole transport layer.
6. The organic electroluminescence device according to claim 5 , wherein the electron transport layer has an energy gap that is larger than an energy gap of the organic light-emitting layer.
7. The organic electroluminescence device according to claim 6 , wherein the electron transport layer comprises a deposited film.
8. An organic electroluminescence unit provided with 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 configured by a coated film;
an organic light-emitting layer configured by a coated film;
an electron transport layer; and
a second electrode,
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.
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 configured by a coated film;
an organic light-emitting layer configured by a coated film;
an electron transport layer; and
a second electrode,
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.