Organic light-emitting device with transparent electrode having both conductivity and optical transparency

1. An organic light-emitting device comprising:

an internal light extraction layer comprising a scattering layer and a smooth layer; and

a transparent electrode comprising an underlying layer and an electrode layer, wherein

the transparent electrode is provided on a smooth layer side of the internal light extraction layer,

the internal light extraction layer has a refractive index in the range of 1.7 to less than 2.5,

the smooth layer has a refractive index in the range of 1.7 or more, and

the electrode layer comprises silver or an alloy comprising silver as a main component.

2. The organic light-emitting device according to claim 1 , wherein

the scattering layer contains particles with an average particle size of 0.2 μm to less than 1 μm and a refractive index of 1.7 to less than 3.0.

3. The organic light-emitting device according to claim 1 , wherein

the scattering layer has a smooth layer-side surface formed to have a dip-and-bump structure.

4. The organic light-emitting device according to claim 1 , wherein

the underlying layer comprises a nitrogen atom-containing compound.

5. The organic light-emitting device according to claim 4 , wherein

the nitrogen atom-containing compound has a heterocyclic ring containing a nitrogen atom as a heteroatom.

6. The organic light-emitting device according to claim 4 , wherein

the nitrogen atom-containing compound has a pyridine group.

7. The organic light-emitting device according to claim 4 , wherein

the nitrogen atom-containing compound is a compound represented by formula (1):

[Chemical formula 1]

(Ar1) n 1-Y1  Formula (1)

wherein n1 represents an integer of 1 or more,

Y1 represents a substituent when n1 is 1 or Y1 represents a simple bond or a n1-valent linking group when n1 is 2 or more,

Ar1 represents a group represented by formula (A):

wherein X represents —N(R)—, —O—, —S—, or —Si(R)(R′)—, E1 to E8 each independently represent —C(R1)= or —N═, R, R′, and R1 each independently represent a hydrogen atom, a substituent, or a linking site to Y1, * represents a linking site to Y1, Y2 represents a simple bond or a divalent linking group, Y3 and Y4 each represent a group derived from a five- or six-membered aromatic ring, at least one of Y3 and Y4 represents a group derived from an aromatic heterocyclic ring containing a nitrogen atom as a ring-constituting atom, and n2 represents an integer of 1 to 4,

when n1 is 2 or more, a plurality of occurrences of Ar1 may be the same or different, and

the compound represented by formula (1) has, in its molecule, at least two condensed aromatic heterocyclic rings each formed by condensation of three or more rings.

8. The organic light-emitting device according to claim 2 , wherein

the underlying layer comprises a nitrogen atom-containing compound.

9. The organic light-emitting device according to claim 5 , wherein

the nitrogen atom-containing compound has a pyridine group.

10. The organic light-emitting device according to claim 5 , wherein

the nitrogen atom-containing compound is a compound represented by formula (1):

[Chemical formula 3]

(Ar1) n 1-Y1  Formula (1)

wherein n1 represents an integer of 1 or more,

Y1 represents a substituent when n1 is 1 or Y1 represents a simple bond or a n1-valent linking group when n1 is 2 or more,

Ar1 represents a group represented by formula (A):

wherein X represents —N(R)—, —O—, —S—, or —Si(R)(R′)—, E1 to E8 each independently represent —C(R1)= or —N═, R, R′, and R1 each independently represent a hydrogen atom, a substituent, or a linking site to Y1, * represents a linking site to Y1, Y2 represents a simple bond or a divalent linking group, Y3 and Y4 each represent a group derived from a five- or six-membered aromatic ring, at least one of Y3 and Y4 represents a group derived from an aromatic heterocyclic ring containing a nitrogen atom as a ring-constituting atom, and n2 represents an integer of 1 to 4,

when n1 is 2 or more, a plurality of occurrences of Ar1 may be the same or different, and

the compound represented by formula (1) has, in its molecule, at least two condensed aromatic heterocyclic rings each formed by condensation of three or more rings.

11. The organic light-emitting device according to claim 3 , wherein

the underlying layer comprises a nitrogen atom-containing compound.

12. The organic light-emitting device according to claim 6 , wherein

the nitrogen atom-containing compound is a compound represented by formula (1):

[Chemical formula 5]

(Ar1) n 1-Y1  Formula (1)

wherein n1 represents an integer of 1 or more,

Y1 represents a substituent when n1 is 1 or Y1 represents a simple bond or a n1-valent linking group when n1 is 2 or more,

Ar1 represents a group represented by formula (A):

wherein X represents —N(R)—, —O—, —S—, or —Si(R)(R′)—, E1 to E8 each independently represent —C(R1)= or —N═, R, R′, and R1 each independently represent a hydrogen atom, a substituent, or a linking site to Y1, * represents a linking site to Y1, Y2 represents a simple bond or a divalent linking group, Y3 and Y4 each represent a group derived from a five- or six-membered aromatic ring, at least one of Y3 and Y4 represents a group derived from an aromatic heterocyclic ring containing a nitrogen atom as a ring-constituting atom, and n2 represents an integer of 1 to 4,

when n1 is 2 or more, a plurality of occurrences of Ar1 may be the same or different, and

the compound represented by formula (1) has, in its molecule, at least two condensed aromatic heterocyclic rings each formed by condensation of three or more rings.