JP2002246181A - Organic light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic light-emitting element having improved driving durability. SOLUTION: In this organic light-emitting element, a transparent electrode 12 and a back surface electrode are arranged on a base board 10, and an organic light-emitting layer containing at least one fluorescent material and/or at least one phosphorescent material is arranged between the transparent electrode 12 and the back surface electrode. This organic light-emitting element emits light, when a voltage is impressed between the transparent electrode 12 and the back electrode. In the periphery of the light-emitting face of the transparent electrode 12, a layer 14 made of a material different in a refractive index from a material for the transparent electrode is arranged. The layer 14 arranged in the periphery of the light-emitting face of the transparent electrode 12 is made of a material, having light reflectance of 85% or higher at one wavelength at least in the EL spectrum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an organic light emitting device, and more particularly, to an organic light emitting device suitable for use in a planar light emitting device.

[0002]

2. Description of the Related Art An organic light emitting device using an organic substance has attracted attention as a new optical device because it can be easily applied to a planar light emitting device. Specifically, it is expected to be used as a solid-state light-emitting inexpensive large-area full-color display element or a writing light source array, and many developments have been made. In general, an organic light-emitting device includes a light-emitting layer and a pair of opposed electrodes (a back electrode and a transparent electrode) sandwiching the light-emitting layer. In the organic light emitting device, when an electric field is applied between the pair of opposed electrodes,
Electrons are injected from the back electrode and holes are injected from the transparent electrode. The electrons and holes are recombined in the light emitting layer, and when the energy level returns from the conduction band to the valence band, energy is emitted as light to emit light.
By the way, the conventional organic light emitting device has a problem that the driving voltage is high and the light emission luminance and the light emission efficiency are low. However, in recent years, it has been examined by many engineers and an efficiency comparable to an inorganic LED has been obtained. .

However, in an organic light emitting device,
The driving durability is inferior, and further improvement has been desired.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic light emitting device having improved driving durability.

[0005]

The object of the present invention has been attained by the following means. (1) having a transparent electrode and a back electrode on a substrate, and having an organic light emitting layer containing at least one fluorescent substance and / or at least one phosphorescent substance between the transparent electrode and the back electrode; An organic light emitting device which emits light when a voltage is applied between a transparent electrode and a back electrode, wherein a layer made of a material having a different refractive index from the transparent electrode is provided around a light emitting surface of the transparent electrode. . (2) a transparent electrode and a back electrode on the substrate, and an organic light-emitting layer containing at least one fluorescent substance and / or at least one phosphorescent substance between the transparent electrode and the back electrode; In an organic light-emitting device that emits light when a voltage is applied between a transparent electrode and a back electrode, a layer made of a material having a reflectance of 85% or more at at least one wavelength of an EL spectrum is provided around the light-emitting surface of the transparent electrode. An organic light emitting device, characterized in that: (3) When the peak intensity of the EL spectrum is adjusted to 100% of the absorbance of the at least one fluorescent substance or the phosphorescent substance, the area S overlaps the overlap between the EL spectrum and the absorbance spectrum of the fluorescent substance or the phosphorescent substance. Is less than or equal to 0.10 of the area S light of the EL spectrum, the organic light-emitting device according to the above (1) or (2). (4) The organic light-emitting device according to any one of (1) to (3), wherein at least one of the fluorescent substance and / or the phosphorescent substance is an orthometalated complex.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The organic light emitting device of the present invention has 1) a transparent electrode and a back electrode on a substrate, and at least one fluorescent substance and / or at least one between the transparent electrode and the back electrode. Having an organic light emitting layer containing one phosphorescent substance,
An organic light emitting device that emits light when a voltage is applied between the transparent electrode and the back electrode, wherein an organic light emitting device provided with a layer made of a material having a different refractive index from the material of the transparent electrode around the light emitting surface of the transparent electrode; and 3.) The organic light-emitting device according to claim 1, wherein a layer made of a material having a reflectance of 85% or more of light at at least one wavelength of the EL spectrum is provided around a light-emitting surface of the transparent electrode.

1) A material having a different refractive index from the material of the transparent electrode used in the periphery of the light emitting surface of the transparent electrode is made of a material having a refractive index relatively determined from the relationship with the refractive index of the transparent electrode. It is necessary that the material having a different refractive index is different from the material of the transparent electrode at least, but the difference between the material of the transparent electrode and the material of the transparent electrode is preferably 0.1 to 2.0.
And more preferably 0.2 to 1.0. It is desirable that the difference in the refractive index between the material of the transparent electrode and the material provided around the light emitting surface of the transparent electrode is large, but such a material is small, while if the difference is too small, it is taken out from the substrate side. The amount of light decreases.

As the material having a different refractive index, a material having the above-described refractive index, a small absorption coefficient, and a high density is desired. Therefore, metal oxides and alkali halides are preferred. Examples of the metal oxide include S
Examples of iO ₂ , Al ₂ O ₃ , MgO, TiO ₂ , and alkali halides include MgF ₂ , LiF, and CaF ₂ . Among these, from the viewpoint of denseness and durability, SiO 2 is particularly preferred.
₂ , TiO _{2 and the} like are preferable.

2) A material having a reflectance of 85% or more at at least one wavelength of the EL spectrum provided around the light emitting surface of the transparent electrode preferably has a reflectance of 90%.
As described above, the reflectance is preferably 95% or more. The material having a high light reflectance is preferably as high as possible. However, at least 85% or more is sufficient for exhibiting the effects of the present invention.

Materials having a light reflectance of 85% or more include metals such as Al, Cr, Au, In, Pt, and Z.
Examples include r, Ti, Ir, Cu, Zr, Ag, and Pa, and may be an alloy. Among these, Al, Cr, Au, and the like having high reflectivity over a wide wavelength range are preferable, and Al is particularly preferable.

Both the material described in 1) and the material described in 2) are formed in a layer around the light emitting surface of the transparent electrode. Here, the peripheral portion of the light emitting surface of the transparent electrode refers to the peripheral portion where the light emitting surface of light can be observed when viewed from a direction perpendicular to the transparent substrate surface. in this case,
The peripheral portion is preferably the peripheral edge of the transparent electrode and the outer peripheral portion of the peripheral edge. However, the peripheral portion does not necessarily mean the entire peripheral region, but also includes a case where a layer is formed in most of the peripheral region and there is a region where a layer is not formed partially in the peripheral region. The layer provided on the periphery is
Basically, it may be arranged at any distance from the light emitting surface. However, if the layer that reflects light with respect to the light emitting surface also covers the central portion of the light emitting surface too much, the amount of light extracted from the substrate side decreases, so it is desirable that the light emitting surface be as close as possible to the end surface. Specifically, the distance from the end face of the light emitting surface to the center of the light emitting surface is desirably 200 mm or less, more desirably 50 mm or less, and most desirably 1 mm or less.

In the case of the material described in 1) and the material described in 2), the thickness of each layer is preferably 0.02
０．５0.5 μm, preferably 0.2-0.4 μm.
The layer 14 can be formed by any means, but can be formed by a method such as vapor deposition, EB vapor deposition, and sputtering. In the present invention, the layer made of the above-described material is formed around the light-emitting surface of the transparent electrode as described above, thereby suppressing light propagating inside the transparent electrode and increasing the amount of light extracted from the substrate. be able to.

Further, in the present invention, one of the absorptivity of at least one fluorescent substance or phosphorescent substance contained in the element is one.
When the peak intensity of the EL spectrum is adjusted to the intensity of 00%, the area S overlap of the EL spectrum and the absorption spectrum of the fluorescent substance or the phosphorescent substance is 0.10 or less of the area S light of the EL spectrum. Is desirable, and 0.0
The value is more preferably 5 or less, further preferably 0.02 or less, and most preferably 0.01 or less. The absorptance is 1 when the incident light intensity is I input and the output light intensity is I output.
Given by -I out / I in.

The effect of the present invention is very remarkable for an organic light emitting device containing an orthometalated complex. It is speculated that the orthometalated complex may have a CT transition at a portion overlapping with the EL spectrum, and that the excited state due to the CT transition in the thin film is more unstable than the excited state of the normal electronic transition. The orthometalated complex in the present invention is described, for example, in "Organometallic Chemistry-Fundamentals and Applications-" by Akio Yamamoto, pp. 150, 232, Shokabosha (published in 1982).
And H. Yersin, Photochemistry and Photophysics of C
oordination Compounds ", pp. 71-77, 135-14
6 is a generic term for a group of compounds described in Springer-Verlag (issued in 1987) and the like. There are various ligands forming an orthometalated complex, and these ligands are also described in the above literature. Preferred ligands are 2
-Phenylpyridine derivative, 7,8-benzoquinoline derivative, 2- (2-thienyl) pyridine derivative, 2- (1
-Naphthyl) pyridine derivative, 2-phenylquinoline derivative and the like. These derivatives may have a substituent as needed. Examples of the metal forming the orthometalated complex include Ir, Pd, and Pt.
Iridium (Ir) complexes are particularly preferred. The ortho-metalated complex used in the present invention may have other ligands in addition to the ligand necessary for forming the ortho-metalated complex. Incidentally, the ortho-metalated complex used in the present invention,
A compound that emits light from a triplet exciton is also included, which is preferable from the viewpoint of improving luminous efficiency.

The structure of the organic light emitting layer in the present invention, that is, the structure between the electrodes will be described. Specific configurations include a transparent electrode / light-emitting layer / electron transport layer / back electrode, and a transparent electrode / hole transport layer / light-emitting layer / electron transport layer / back electrode, and the like (the reverse configuration is also possible). Further, a plurality of light-emitting layers and hole transport layers may be provided, or a hole injection layer or an electron injection layer may be provided.

The electron transporting organic material which can be used for the electron transporting layer in the present invention includes oxadiazole derivatives, triazole derivatives, triazine derivatives, nitro-substituted fluorenone derivatives, thiopyrandioxide derivatives, diphenylquinone derivatives, perylenetetracarboxyl derivatives. And anthraquinodimethane derivatives, fluorenylidenemethane derivatives, anthrone derivatives, perinone derivatives, oxine derivatives, quinoline complex derivatives and the like. Of course, organic materials other than those described above may be used.

In the present invention, it is very desirable to provide an insulating layer thin film as an electron injection layer. As a preferable material, a layer of aluminum oxide or lithium fluoride having a thin layer of about 0.01 to 10 nm is known. Of course, other materials may be used.

Examples of the hole-transporting compound used in the hole-transporting layer include polymers such as poly-N-vinylcarbazole, polyphenylenevinylene derivatives, polyphenylene, polythiophene, polymethylphenylsilane, and polyaniline; triazole derivatives; oxadiazole derivatives;
Imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, carbazole derivatives,
Styryl anthracene derivative, fluorenone derivative, hydrazone derivative, stilbene derivative, porphyrin derivative such as phthalocyanine, aromatic tertiary amine compound and styrylamine compound, butadiene compound, benzidine derivative, polystyrene derivative, triphenylmethane derivative, tetraphenylbenzine derivative, Starburst polyamine derivatives and the like can be used.

The compound used in the light-emitting layer of the organic light-emitting device of the present invention is not particularly limited as long as it can be excited to emit fluorescence. For example, oxinoid compounds, perylene compounds, coumarins Compound, azacoumarin compound, oxazole compound, oxadiazole compound, perinone compound, pyrrolopyrrole compound, naphthalene compound, anthracene compound, fluorene compound, fluoranthene compound, tetracene compound, pyrene compound, coronene compound, quinolone compound and azaquinolone compound, pyrazoline derivative and Pyrazolone derivatives, rhodamine compounds, chrysene compounds, phenanthrene compounds, cyclopentadiene compounds, stilbene compounds, diphenylquinone compounds, styryl compounds,
Distyrylbenzene compounds, butadiene compounds, dicyanomethylenepyran compounds, dicyanomethylenethiopyran compounds, fluorescein compounds, pyrylium compounds, thiapyrylium compounds, selenapyrylium compounds, telluropyrylium compounds, aromatic aldadienes, oligophenylene compounds, xanthene compounds, and thioxanthenes Compounds, cyanine compounds, acridine compounds, acridone compounds, quinoline compounds, metal complexes of 8-hydroxyquinoline compounds, benzoquinolinol beryllium complexes, metal complexes of 2,2'-bipyridine compounds, complexes of Schiff salts with Group III metals, oxa A metal complex of a diazole compound, a rare earth complex, or the like is used.

These luminescent materials may be used alone or in combination. Further, a polymer light emitting material may be used. Examples of the polymer light-emitting material include a π-conjugated system such as a poly-p-phenylenevinylene derivative, a polyfluorene derivative, and a polythiophene derivative, and a low-molecular dye and tetraphenyldiamine or triphenylamine introduced into a main chain or a side chain. And the like. It is also possible to use a mixture of a high molecular light emitting material and a low molecular light emitting material.

According to the present invention, in addition to these constitutions, a conductive polymer layer may be provided between the transparent electrode and the hole transport layer (the light emitting layer when no hole transport layer is provided) in contact with the transparent electrode. Good. By providing this layer, the thickness of the organic compound layer can be increased with almost no increase in drive voltage, and uneven brightness and short-circuit are improved. As the conductive polymer, polyaniline derivatives, polythiophene derivatives and polypyrrole derivatives described in WO-98 / 05187 and the like are preferable. These derivatives are protonic acids (for example, camphor sulfonic acid, p-toluene sulfonic acid, styrene sulfonic acid, polystyrene sulfonic acid, etc.)
And can be used in a mixed state. These derivatives can be used by mixing with other polymers (for example, polymethyl methacrylate (PMMA), poly-N-vinylcarbazole (PVCz), etc.) as necessary. The surface resistance of the conductive polymer layer is desirably 10,000 Ω / □ or less. The thickness of the conductive polymer layer is 10 nm to 100
0 nm, particularly 20 nm to 200 nm, is desirable.

Organic compound layers such as a hole transporting layer, an electron transporting layer, a light emitting layer, and a conductive polymer layer are formed by vacuum deposition, sputtering, dipping, spin coating, casting, bar coating, roll coating, and the like. And the like, using a known method. Multilayer coating is also possible by using different solvents.

Next, the electrode material in the present invention will be described. As a transparent electrode material, tin oxide, indium tin oxide (ITO), indium zinc oxide and the like are well known. A metal thin film having a large work function such as gold or platinum may be used. Further, an organic material such as polyaniline, polythiophene, polypyrrole, or a derivative thereof may be used. The transparent conductive film is described in detail in "New Development of Transparent Conductive Film", supervised by Yutaka Sawada, published by CMC (1999), and can be applied to the present invention.

As a back electrode material, L having a low work function is used.
Alkali metals such as i and K and alkaline earth metals such as Mg and Ca are desirable from the viewpoint of electron injection. Further, Al or the like, which is hardly oxidized and stable, is also desirable. In order to achieve both stability and electron injecting property, a layer containing two or more kinds of materials may be used, and those materials are described in detail in JP-A-2-15595 and JP-A-5-121172.

Surface of back electrode (opposite side of organic compound layer)
May be provided with a protective layer for blocking moisture and air. Regarding the protective layer for this purpose, see JP-A-7-85974.
No. etc. Furthermore, it is desirable to seal using glass or a poly (chlorotrifluoroethylene) sheet. A desiccant, a water-repellent fluorine-based inert liquid, or the like may be inserted therein. The inorganic layer such as the transparent electrode and the back electrode can be formed by a known method such as a vacuum evaporation method, a sputtering method, and an ion plating method.

In the present invention, a transparent substrate is suitably used as the substrate, and a plastic substrate can be used in addition to a normal glass substrate. The plastic substrate needs to be excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, workability, low air permeability, and low moisture absorption. Examples of such a material include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polystyrene, polycarbonate, polyether sulfone, polyarylate, allyl diglycol carbonate, and polyimide. It is preferable to provide a moisture permeation preventing layer (gas barrier layer) on the surface of these substrates or on the surface opposite to the electrodes (the back surface). The moisture permeation preventing layer (gas barrier layer) is preferably made of an inorganic substance such as silicon nitride or silicon oxide, and can be formed by, for example, a high frequency sputtering method. Further, a hard coat layer or an undercoat layer may be provided as necessary.

In general, a light emitting element is used for an organic light emitting element.
To prevent moisture and oxygen from entering the constituent layers
Is provided. These sealing materials include
Trafluoroethylene and at least one comonomer
A copolymer containing a cyclic structure
Copolymer, polyethylene, polypropylene, polymethyl
Methacrylate, polyimide, polyurea, polyteto
Lafluoroethylene, polychlorotrifluoroethylene
, Polydichlorodifluoroethylene, chlorotrifur
Select from ethylene and dichlorodifluoroethylene
Two or more copolymers, water-absorbing material with water absorption of 1% or more
Substance with water quality and water absorption of 0.1% or less, In, S
gold such as n, Pb, Au, Cu, Ag, Al, Ti, Ni
Genus, MgO, SiO, SiO_Two, Al_TwoO_Three, GeO, N
iO, CaO, BaO, Fe_TwoO_Three, Y_TwoO _Three, TiO_Twoetc
Metal oxide, MgF_Two, LiF, AlF_Three, CaF_Twoetc
Metal fluoride, perfluoroalkane, perfluoro
Liquid fluorinated carbon such as amines and perfluoroethers
And adsorption of water and oxygen to the liquid fluorinated carbon
An agent in which an agent is dispersed is used.

The patterning of the electrode can be performed by chemical etching such as photolithography, or can be physically etched by using a laser or the like. Alternatively, vacuum evaporation, sputtering, or the like may be performed with a mask overlapped. In the present invention, the organic EL element can be used in a single pixel, but is preferably used as a dot array provided in a plurality of rows for each emission color. Each emission color may be one line or a plurality of lines.
The size of one pixel is 10 to 500 μm, preferably 50 μm.
３００300 μm.

[0029]

EXAMPLE (Preparation of Substrate) As shown in FIG. 1, a 2.5 cm square glass substrate 10 having a thickness of 0.2 cm was washed with ITO.
The transparent electrode 12 was obtained by sputtering at 2 μm and patterning it. A material having a refractive index as shown in Table 1 and a material having a reflectance as shown in Table 2 were formed on the transparent substrate 12 by a layer forming method shown in Table 1 to have a thickness of 0.22 μm. Next, patterning was performed as shown in FIG. 2, and layers 14 made of the above-mentioned materials were formed on the periphery of the transparent electrode 12, thereby forming substrates A to G. As a comparative example, as shown in FIG.
A substrate in which only O was patterned was used for comparison.

[0030]

[Table 1]

[0031]

[Table 2]

(Preparation of Organic Layer) The substrates A to G and the comparative substrate were ultrasonically cleaned with acetone and IPA. Finally I
After PA boiling cleaning, UV / O ₃ cleaning was performed. Using the above substrate, the following device was produced. 4,4
'-Bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD) was deposited at a deposition rate of 3 to 4 / sec.
c to a thickness of 400 °, compound 1 is deposited at a deposition rate of 3 to 4 ° / sec to a thickness of 200 °, and tris (8-quinolylato) aluminum (Alq) is deposited at a deposition rate of 3 to 6 ° / sec. 400mm thick in sec
Vapor deposition was performed so that From above, the cathode (back electrode)
Was deposited at a molar ratio of Mg / Ag = 10: 1 and a thickness of 0.6 μm. Thereafter, Ag alone was vapor-deposited on the cathode (back electrode) to a thickness of 0.5 μm to produce a device 1.

Further, compounds 2 and 3 shown below were vapor-deposited in place of compound 1 to prepare devices 2 and 3. The absorption spectra of Compounds 1 to 3 and the EL spectra of Devices 1 to 3 are shown in FIGS. 4 to 6, compounds 1 to
3 is shown by a solid line, and the EL
The spectrum is shown by the dashed line.

[0034]

Embedded image

The devices 4 and 5 were prepared in exactly the same manner except that Compound 4 was used as a host material and Compounds 5 and 6 were doped as doping materials at 6% by mass instead of Compound 1 described above.
Was prepared. In addition, an element 6 was produced in exactly the same manner except that the compound 7 was used as a host material and the compound 8 was doped as a dope material. The absorption spectra of Compounds 5, 6, and 8 and the EL spectra of Devices 4 to 6 are shown in FIGS. 7 to 9, the absorption spectra of Compounds 4 to 6 are shown by solid lines, and the EL spectra of Devices 4 to 6 are shown by broken lines.

[0036]

Embedded image

(Evaluation of Driving Durability) The driving durability of the organic light emitting device was evaluated as follows. Output power is 12
A constant current drive was performed so that the output power became W / m ² , and the time when the output power became half was measured. Table 3 shows the results.

[0038]

[Table 3]

From Table 3, it can be seen that an organic light-emitting device in which a layer made of a material having a different refractive index is formed around the light-emitting surface of the transparent electrode, or the reflectance of light at at least one wavelength of the EL spectrum at the light-emitting surface of the transparent electrode. , An organic light-emitting device having a layer made of a material of 85% or more has the same output power even when using the same light-emitting material as compared to an organic light-emitting device manufactured by a comparative substrate having no layer. This shows that the driving durability is improved.

Further, when the peak intensity of the EL spectrum is adjusted to 100% of the absorbance of at least one fluorescent substance or phosphorescent substance, the area S overlap of the EL spectrum and the absorbance spectrum of the substance becomes It can be seen that the effect of the above-described invention is more remarkably obtained in the element (element 1 and element 6) using a light-emitting material having an area S light of the EL spectrum of 0.10 or less. Furthermore, it can be seen that the elements 4 to 6 using the ortho-metalated complex have extremely large effects. As described above, the effect of the present invention was confirmed.

Next, an organic light emitting device was manufactured in which the distance between the transparent electrode and the back electrode was changed by changing the amount of the organic substance to be deposited and changing the thickness of the organic layer.
The half-life of the output power was measured in the same manner as described above. Table 4 shows the results.

[0042]

[Table 4]

From the results shown in Table 4, it was confirmed that the organic light-emitting device of the present invention has a long output power half-life and high driving durability even when the distance between the transparent electrode and the back electrode is changed. did it.

[0044]

As described above, according to the present invention, it is possible to provide an organic light emitting device having improved driving durability.

[Brief description of the drawings]

FIG. 1A is a plan view of a component in a manufacturing process of an organic light-emitting device of the present invention, and FIG. 1B is a cross-sectional view taken along line aa ′ of FIG.

FIG. 2A is a plan view of a component in another manufacturing process of the organic light emitting device of the present invention, and FIG. 2B is aa of FIG.
FIG. 3C is a cross-sectional view taken along line bb ′ of FIG.

FIG. 3A is a plan view of components of an organic light-emitting device according to a comparative example, and FIG. 3B is a cross-sectional view taken along line aa ′ of FIG.

FIG. 4 is a spectrum diagram showing an area S overlap of an absorption spectrum / an area S light of an EL spectrum in the organic light emitting device (element 1) of the present invention.

FIG. 5 is a spectrum diagram showing an area S overlap of an absorption spectrum / an area S light of an EL spectrum in the organic light emitting device (element 2) of the present invention.

FIG. 6 is a spectrum diagram showing an area S overlap of an absorption spectrum / an area S light of an EL spectrum in the organic light emitting device (element 3) of the present invention.

FIG. 7 is a spectrum diagram showing the area S overlap of the absorption spectrum / the area S light of the EL spectrum in the organic light emitting device (element 4) of the present invention.

FIG. 8 is a spectrum diagram showing an area S overlap of an absorption spectrum / an area S light of an EL spectrum in the organic light emitting device (element 5) of the present invention.

FIG. 9 is a spectrum diagram showing an area S overlap of an absorption spectrum / an area S light of an EL spectrum in the organic light emitting device (element 6) of the present invention.

[Explanation of symbols]

 10 Glass substrate 12 Transparent electrode (ITO) 14 layer (peripheral part)

Claims (4)

[Claims] A transparent electrode and a back electrode on a substrate,
An organic light emitting device having an organic light emitting layer containing at least one fluorescent substance and / or at least one phosphorescent substance between the transparent electrode and the back electrode, and emitting light when a voltage is applied between the transparent electrode and the back electrode 3. The organic light-emitting device according to claim 1, wherein a layer made of a material having a different refractive index from the material of the transparent electrode is provided around a light-emitting surface of the transparent electrode. 2. A transparent electrode and a back electrode on a substrate,
An organic light emitting device having an organic light emitting layer containing at least one fluorescent substance and / or at least one phosphorescent substance between the transparent electrode and the back electrode, and emitting light when a voltage is applied between the transparent electrode and the back electrode 3. The organic light-emitting device according to claim 1, wherein a layer made of a material having a reflectance of 85% or more of light at at least one wavelength of the EL spectrum is provided around the light-emitting surface of the transparent electrode. 3. The area where the EL spectrum overlaps with the absorption spectrum of the fluorescent substance or the phosphorescent substance when the peak intensity of the EL spectrum is adjusted to 100% of the absorption rate of the at least one fluorescent substance or the phosphorescent substance. S heavy,
The organic light-emitting device according to claim 1, wherein the area S light of the EL spectrum is 0.10 or less. 4. The organic light-emitting device according to claim 1, wherein at least one of the fluorescent substance and / or the phosphorescent substance is an ortho-metallated complex.